Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Biology (134)
- Social and Behavioral Sciences (134)
- Medicine and Health Sciences (97)
- Physical Sciences and Mathematics (97)
- Biochemistry, Biophysics, and Structural Biology (86)
-
- Pharmacology, Toxicology and Environmental Health (62)
- Microbiology (52)
- Ecology and Evolutionary Biology (45)
- Arts and Humanities (43)
- Animal Sciences (39)
- Genetics and Genomics (30)
- Neuroscience and Neurobiology (30)
- Biochemistry (26)
- Immunology and Infectious Disease (26)
- Molecular Biology (26)
- Kinesiology (25)
- Zoology (22)
- Plant Sciences (21)
- Cell and Developmental Biology (20)
- Medical Sciences (20)
- Physiology (18)
- Psychology (16)
- Chemistry (15)
- Evolution (15)
- Engineering (14)
- Agriculture (13)
- Genetics (13)
- Nutrition (13)
- Agricultural and Resource Economics (12)
- Keyword
-
- Humans (40)
- HIV Protease (31)
- HIV Protease Inhibitors (29)
- CMMB (26)
- HIV-1 (26)
-
- Models, Molecular (25)
- Crystallography, X-Ray (22)
- Protein Conformation (21)
- Binding Sites (19)
- Drug Resistance, Viral (17)
- Mutation (17)
- Course Materials (16)
- Animals (15)
- Molecular Sequence Data (13)
- Substrate Specificity (13)
- Amino Acid Sequence (12)
- Structure-Activity Relationship (12)
- Mice (11)
- Articles (10)
- Hydrogen Bonding (10)
- Proteins (9)
- Thermodynamics (9)
- Amyloid (8)
- Biology (8)
- Cell Line (8)
- Fibril (8)
- Protein Binding (8)
- Sulfonamides (8)
- Casein (7)
- Drug Design (7)
- Publication
-
- Celia A. Schiffer (73)
- Heath Ecroyd (29)
- Dennis G. Searcy (22)
- Jean J. Huang (16)
- Katherine A. Fitzgerald (12)
-
- Briana Eileen Timmerman (11)
- Sandra Jones (11)
- Lesley Head (10)
- Emma Barkus (9)
- Marcel Adam Just (8)
- Mike Climstein (7)
- Pr. Mamoudou H. DICKO, PhD (7)
- Erik Edward Nordman (6)
- Ahmed Mustafa Dr. (5)
- Ed L. Frederickson (5)
- Frederick M. Cohan (5)
- Mark A. Jordan (5)
- Michael A. Rogawski (5)
- Ryan Kerney (5)
- Sharon Robinson (5)
- Kim Lewis (4)
- Mark S. Miller (4)
- Philip T. Reiss (4)
- Soam Prakash (4)
- Stephen T Asma (4)
- Wendy M Schluchter (4)
- Xuemin (Sam) Wang (4)
- Yan Lu (4)
- Amru Bin Nasrulhaq Boyce (3)
- Ann E Williams (3)
Articles 1 - 30 of 536
Full-Text Articles in Life Sciences
Economic And Social Impacts Of Wildfires And Invasive Plants In American Deserts: Lessons From The Great Basin, Mark Brunson, John Tanaka
Economic And Social Impacts Of Wildfires And Invasive Plants In American Deserts: Lessons From The Great Basin, Mark Brunson, John Tanaka
John A Tanaka
Research on the impacts of wildfire and invasive plants in rangelands has focused on biophysical rather than human dimensions of these environmental processes. We offer a synthetic perspective on economic and social aspects of wildfire and invasive plants in American deserts, focusing on the Great Basin because greater research attention has been given to the effects of cheatgrass expansion than to other desert wildfire/invasion cycles. We focus first on impacts at the level of the individual decision-maker, then on impacts experienced at the human community or larger socio-political scales. Economic impacts of wildfire differ from those of invasive grasses because …
Chapter 9. A Social And Economic Assessment Of Rangeland Conservation Practices, John Tanaka, Mark Brunson, L. Allen Torell
Chapter 9. A Social And Economic Assessment Of Rangeland Conservation Practices, John Tanaka, Mark Brunson, L. Allen Torell
John A Tanaka
In this chapter, we examine the literature related to the economic and social aspects of ecosystem services impacted by the conservation practices of the Natural Resources Conservation Service (NRCS) of prescribed grazing, prescribed burning, brush management, upland wildlife habitat, riparian management, and range planting. In addition, we examine the social and economic aspects of invasive species management that cross different conservation practices...
Alterg Anti-Gravity Treadmill Walking Program On An Extremely Obese Female, Jane Shimon, Shawn Simonson, Elaine Long, Brooke Lester
Alterg Anti-Gravity Treadmill Walking Program On An Extremely Obese Female, Jane Shimon, Shawn Simonson, Elaine Long, Brooke Lester
Elaine M. Long
No abstract provided.
Genome-Scale Dynamics Modeling Of The Competition Between Rhodoferax And Geobacter In Anoxic Subsurface Environments, Derek Lovley, Kai Zhuang, Mounir Izallalen, Paula Museor, Hanno Richter, Carla Risso, Radhakrishnan Mahadevan
Genome-Scale Dynamics Modeling Of The Competition Between Rhodoferax And Geobacter In Anoxic Subsurface Environments, Derek Lovley, Kai Zhuang, Mounir Izallalen, Paula Museor, Hanno Richter, Carla Risso, Radhakrishnan Mahadevan
Carla Risso
The advent of rapid complete genome sequencing, and the potential to capture this information in genome-scale metabolic models, provide the possibility of comprehensively modeling microbial community interactions. For example, Rhodoferax and Geobacter species are acetate-oxidizing Fe(III)-reducers that compete in anoxic subsurface environments and this competition may have an influence on the in situ bioremediation of uranium-contaminated groundwater. Therefore, genome-scale models of Geobacter sulfurreducens and Rhodoferax ferrireducens were used to evaluate how Geobacter and Rhodoferax species might compete under diverse conditions found in a uranium-contaminated aquifer in Rifle, CO. The model predicted that at the low rates of acetate flux expected …
A Review Of Baobab (Adansonia Digitata) Products: Effect Of Processing Techniques, Medicinal Properties And Uses, Donatien Kabore, Hagrétou Sawadogo-Lingani, Bréhima Diawara, Clarise Compaoré, Mamoudou H. Dicko Prof., Mogens Jacobsen
A Review Of Baobab (Adansonia Digitata) Products: Effect Of Processing Techniques, Medicinal Properties And Uses, Donatien Kabore, Hagrétou Sawadogo-Lingani, Bréhima Diawara, Clarise Compaoré, Mamoudou H. Dicko Prof., Mogens Jacobsen
Pr. Mamoudou H. DICKO, PhD
A general literature review including the effect of processing techniques, medicinal value and uses of baobab tree is reported in this manuscript. Baobab tree has multi-purpose uses, as it produces food and non-food products such as medicines, fuel, timber, fodder. Every part of the baobab tree is reported to be useful. The seeds, leaves, roots, flowers, fruit pulp and bark of baobab are edible. Baobab leaves are used in the preparation of soup. Seeds are used as a thickening agent in soups, but they can be fermented and used as a flavouring agent or roasted and eaten as snacks. The …
Identifying Characteristics Of Effective Small Group Learning Valued By Medical Students And Facilitators, Diana T. Robillard, Laura M. Spring, Susan J. Pasquale, Judith A. Savageau
Identifying Characteristics Of Effective Small Group Learning Valued By Medical Students And Facilitators, Diana T. Robillard, Laura M. Spring, Susan J. Pasquale, Judith A. Savageau
Judith A. Savageau
Background: Small group teaching is an important part of undergraduate medical education, providing the ideal setting for learners to clarify misunderstandings, test hypotheses and evaluate ideas. Many schools undergoing curriculum reform have increased the time students spend in small group learning. However, there is an overall paucity of literature examining case-based small group sessions in medical school.
Objective: This study was designed to examine student and facilitator perceptions of effective case-based small group teaching in the pre-clinical years and compare results in order to identify similarities and differences and identify key areas of disconnect so that the small …
Improving Prenatal Education In A Health Center: A Pilot Study, Marcy Keddy Boucher, Hugh Silk, Judith A. Savageau, Katharine C. Barnard, Mary Flynn
Improving Prenatal Education In A Health Center: A Pilot Study, Marcy Keddy Boucher, Hugh Silk, Judith A. Savageau, Katharine C. Barnard, Mary Flynn
Judith A. Savageau
Background: Currently, the timing and variety of health education topics that are covered during prenatal visits are decided upon by the individual physician caring for the patient. Consequently, some patients do not gain exposure to important subject matter that could potentially improve their satisfaction and pregnancy outcomes. Previously reported studies have found evidence that improved patient education may increase rates of breastfeeding (as well as duration), seat belt use during pregnancy, and decrease preterm low birth weight infants. In addition, one study has shown that when prenatal visits are targeted to specific objectives, the number of prenatal visits can …
Assessment Of Client Satisfaction In Six Urban Wic Clinics, Catherine Christie, Julia A. Watkins, Anita Martin, Helen Jackson, Judy E. Perkin, Jacquie Fraser
Assessment Of Client Satisfaction In Six Urban Wic Clinics, Catherine Christie, Julia A. Watkins, Anita Martin, Helen Jackson, Judy E. Perkin, Jacquie Fraser
Catherine Christie
Customer service is a measure of support and courtesy provided to individuals who patronize an organization, and is a factor vital to the success of any business. Programs that strive to meet critical needs of at risk populations, such as the Special Supplementation Nutrition Program for Women, Infants, and Children (WIC), may also benefit from assessment of client satisfaction. The purpose of the study was to examine factors related to customer satisfaction in Duval County Florida WIC clinics and identify potential barriers to participation through a two-year project initiated by the health department and the state university. The study examined …
Public Health Practitioner Expert Opinion For Recommending Revisions To A Community Nutrition Mph Curriculum, Judy E. Perkin, Catherine Christie, Desiree Hayes
Public Health Practitioner Expert Opinion For Recommending Revisions To A Community Nutrition Mph Curriculum, Judy E. Perkin, Catherine Christie, Desiree Hayes
Catherine Christie
Soliciting practitioner input into the planning or revision of Master of Public Health programs is desirable to ensure that students are adequately prepared for public health practice. Members of the American Dietetic Association Public Health/Community Nutrition Dietetic Practice Group (ADA-PH/CNDPG) were surveyed regarding the structure of, as well as the knowledge and skills desirable for, inclusion in a Master of Public Health community nutrition program. A total of 998 surveys were mailed in June 2001 with a return rate of 34%. Approximately 73% of respondents indicated public health employment. The average response regarding optimal time for full-time degree completion was …
Cyp704b1 Is A Long-Chain Fatty Acid V-Hydroxylase Essential For Sporopollenin Synthesis In Pollen Of Arabidopsis, Anna A. Dobritsa, Jay Shrestha, Marc Morant, Franck Pinot, Michiyo Matsuno, Rob Swanson, Birger Lindberg Møller, Daphne Preuss
Cyp704b1 Is A Long-Chain Fatty Acid V-Hydroxylase Essential For Sporopollenin Synthesis In Pollen Of Arabidopsis, Anna A. Dobritsa, Jay Shrestha, Marc Morant, Franck Pinot, Michiyo Matsuno, Rob Swanson, Birger Lindberg Møller, Daphne Preuss
Rob Swanson
Sporopollenin is the major component of the outer pollen wall (exine). Fatty acid derivatives and phenolics are thought to be itsmonomeric building blocks, but the precise structure, biosynthetic route, and genetics of sporopollenin are poorly understood.Based on a phenotypic mutant screen in Arabidopsis (Arabidopsis thaliana), we identified a cytochrome P450, designatedCYP704B1, as being essential for exine development. CYP704B1 is expressed in the developing anthers. Mutations in CYP704B1result in impaired pollen walls that lack a normal exine layer and exhibit a characteristic striped surface, termed zebraphenotype. Heterologous expression of CYP704B1 in yeast cells demonstrated that it catalyzes v-hydroxylation of long-chainfatty acids, …
Fairmount Greenway - A Community Initative, Leah H. Bamberger, Liliana Carvajal, Mary F. Dehais, Yuanfang Gong, John E. Hulsey, Eric C. Kells, Kimberley Klosterman, Pamela Jo Landi, Adam G. Monroy, Seth A. Morrow, Bryan O'Bara, Jie Su, Arianna Thompson, Owen M. White
Fairmount Greenway - A Community Initative, Leah H. Bamberger, Liliana Carvajal, Mary F. Dehais, Yuanfang Gong, John E. Hulsey, Eric C. Kells, Kimberley Klosterman, Pamela Jo Landi, Adam G. Monroy, Seth A. Morrow, Bryan O'Bara, Jie Su, Arianna Thompson, Owen M. White
jie su
This studio was based on the Fairmount Greenway that was developed through a series of public meetings with the neighborhood community and with consultants from the firm Crosby, Schlessinger and Smallridge (CSS). The Fairmount Greenway, while drawing its identity from the traditional greenway model is in fact a reinterpretation of an urban greenway. The greenway path follows along both primary and secondary city streets because of the lack of space along the rail right-of-way. The Fairmount Greenway begins at what will be a new station stop at New Market South Bay near Upham’s Corner in northern Dorchester. The greenway follows …
Map Kinases Couple Hindbrain-Derived Catecholamine Signals To Hypothalamic Adrenocortical Control Mechanisms During Glycemia-Related Challenges, Arshad M. Khan, Kimberly L. Kaminski, Graciela Sanchez-Watts, Todd A. Ponzio, J. Brent Kuzmiski, Jaideep S. Bains, Alan G. Watts
Map Kinases Couple Hindbrain-Derived Catecholamine Signals To Hypothalamic Adrenocortical Control Mechanisms During Glycemia-Related Challenges, Arshad M. Khan, Kimberly L. Kaminski, Graciela Sanchez-Watts, Todd A. Ponzio, J. Brent Kuzmiski, Jaideep S. Bains, Alan G. Watts
Arshad M. Khan, Ph.D.
No abstract provided.
Model For Amorphous Aggregation Processes, Samual Stranks, Heath Ecroyd, Steve Van Sluyter, Elizabeth J. Waters, John A. Carver, Lorenz Von Smekal
Model For Amorphous Aggregation Processes, Samual Stranks, Heath Ecroyd, Steve Van Sluyter, Elizabeth J. Waters, John A. Carver, Lorenz Von Smekal
Heath Ecroyd
The amorphous aggregation of proteins is associated with many phenomena, ranging from the formation of protein wine haze to the development of cataract in the eye lens and the precipitation of recombinant proteins during their expression and purification. While much literature exists describing models for linear protein aggregation, such as amyloid fibril formation, there are few reports of models which address amorphous aggregation. Here, we propose a model to describe the amorphous aggregation of proteins which is also more widely applicable to other situations where a similar process occurs, such as in the formation of colloids and nanoclusters. As first …
Endogenous Redox Activity In Mouse Spermatozoa And Its Role In Regulating The Tyrosine Phosphorylation Events Associated With Sperm Capacitation, Heath W. Ecroyd, Russell C. Jones, Robert J. Aitken
Endogenous Redox Activity In Mouse Spermatozoa And Its Role In Regulating The Tyrosine Phosphorylation Events Associated With Sperm Capacitation, Heath W. Ecroyd, Russell C. Jones, Robert J. Aitken
Heath Ecroyd
We investigated the role of endogenous redox activity in regulating the signal transduction pathway leading to tyrosine phosphorylation in mouse spermatozoa. Endogenous redox activity was monitored using a luminol-peroxidase chemiluminescent probe. Chemiluminescence increased in spermatozoa that were actively undergoing cAMP-mediated tyrosine phosphorylation events associated with capacitation and was inhibited in a dose-dependent manner by addition of catalase or diphenylene iodonium, both of which also inhibited tyrosine phosphorylation within the cell at points downstream of cAMP. Excluding bicarbonate from the incubation medium reduced the redox activity of sperm by 80-90% and dramatically reduced tyrosine phosphorylation. This study provides the first evidence …
Role Of The Epididymis In Sperm Competition, Russell Jones, Jl Dacheux, Brett Nixon, Heath Ecroyd
Role Of The Epididymis In Sperm Competition, Russell Jones, Jl Dacheux, Brett Nixon, Heath Ecroyd
Heath Ecroyd
Although it is generally understood that the testes recruited kidney ducts for reproductive function during the evolution of vertebrates, little is understood of the biological significance of the adaptation. In the context of the evolution of the mammalian epididymis, this report provides evidence that a major role of the epididymis is to enhance a male's chance of achieving paternity in a competitive mating system. A unique example of sperm cooperation, in monotremes is used as evidence that the epididymis produces sperm competition proteins to form groups of 100 sperm into bundles that have a forward motility nearly thrice that of …
Carboxymethylated-K-Casein: A Convenient Tool For The Identification Of Polyphenolic Inhibitors Of Amyloid Fibril Formation, John A. Carver, Peter J. Duggan, Heath Ecroyd, Yanqin Liu, Adam G. Meyer, C E. Tranberg
Carboxymethylated-K-Casein: A Convenient Tool For The Identification Of Polyphenolic Inhibitors Of Amyloid Fibril Formation, John A. Carver, Peter J. Duggan, Heath Ecroyd, Yanqin Liu, Adam G. Meyer, C E. Tranberg
Heath Ecroyd
Reduced and carboxymethylated-κ-casein (RCM-κ-CN) is a milk-derived amyloidogenic protein that readily undergoes nucleation-dependent aggregation and amyloid fibril formation via a similar pathway to disease-specific amyloidogenic peptides like amyloid beta (Aβ), which is associated with Alzheimer’s disease. In this study, a series of flavonoids, many known to be inhibitors of Aβ fibril formation, were screened for their ability to inhibit RCM-κ-CN fibrilisation, and the results were compared with literature data on Aβ inhibition. Flavonoids that had a high degree of hydroxylation and molecular planarity gave good inhibition of RCM-κ-CN fibril formation. IC50 values were between 10- and 200-fold higher with RCM-κ-CN …
Tyrosine Phosphorylation Of Hsp-90 During Mammalian Sperm Capacitation, Heath Ecroyd, Russell Jones, Robert Aitken
Tyrosine Phosphorylation Of Hsp-90 During Mammalian Sperm Capacitation, Heath Ecroyd, Russell Jones, Robert Aitken
Heath Ecroyd
The process of sperm capacitation is correlated with activation of a signal transduction pathway leading to protein tyrosine phosphorylation. Whereas phosphotyrosine expression is an essential prerequisite for fertilization, the proteins that are phosphorylated during capacitation have not yet been identified. In the present study, we observed that a major target of this signaling pathway is the molecular chaperone protein, heat shock protein (HSP)-86, a member of the HSP-90 family of HSPs. We used cross-immunoprecipitation experiments to confirm the tyrosine phosphorylation of HSP-86, a process that is not inhibited by the ansamycin antibiotic, geldanamycin. The general significance of these findings was …
Dissociation From The Oligomeric State Is The Rate-Limiting Step In Fibril Formation By Kappa-Casein, Heath Ecroyd, Tomas Koudelka, David Thorn, Danielle Williams, Glyn Devlin, Peter Hoffmann, John Carver
Dissociation From The Oligomeric State Is The Rate-Limiting Step In Fibril Formation By Kappa-Casein, Heath Ecroyd, Tomas Koudelka, David Thorn, Danielle Williams, Glyn Devlin, Peter Hoffmann, John Carver
Heath Ecroyd
Amyloid fibrils are aggregated and precipitated forms of protein in which the protein exists in highly ordered, long, unbranching threadlike formations that are stable and resistant to degradation by proteases. Fibril formation is an ordered process that typically involves the unfolding of a protein to partially folded states that subsequently interact and aggregate through a nucleation-dependent mechanism. Here we report on studies investigating the molecular basis of the inherent propensity of the milk protein, kappa-casein, to form amyloid fibrils. Using reduced and carboxymethylated kappa-casein ( RCM kappa-CN), we show that fibril formation is accompanied by a characteristic increase in thioflavin …
An Epididymal Form Of Cauxin, A Carboxylesterase-Like Enzyme, Is Present And Active In Mammalian Male Reproductive Fluids, Heath W. Ecroyd, Maya Belghazi, Jl Dacheux, M Miyazaki, T Yamashita, Jl Gatti
An Epididymal Form Of Cauxin, A Carboxylesterase-Like Enzyme, Is Present And Active In Mammalian Male Reproductive Fluids, Heath W. Ecroyd, Maya Belghazi, Jl Dacheux, M Miyazaki, T Yamashita, Jl Gatti
Heath Ecroyd
Mass spectrometric analysis of a prion protein (PrP)-containing complex isolated from ram cauda epididymal fluid revealed a protein that showed homology to a carboxylesterase-like protein previously identified in cat urine (cauxin). Using anticauxin antibodies, immunoreactive bands were detected in corpus and cauda epididymal fluid from all mammals tested (ram, boar, mouse, and cat). In the ram, the protein was also present in seminal fluid but not found to be associated with sperm. The bands reacting with the anti-cauxin antibody coincided with those having esterase activity in a zymographic assay and its levels paralleled the esterase activity of native epididymal fluids. …
The Dissociated Form Of Kappa-Casein Is The Precursor To Its Amyloid Fibril Formation, Heath Ecroyd, David Thorn, Yanqin Liu, John Carver
The Dissociated Form Of Kappa-Casein Is The Precursor To Its Amyloid Fibril Formation, Heath Ecroyd, David Thorn, Yanqin Liu, John Carver
Heath Ecroyd
Bovine milk kappa-casein forms a self-associating oligomeric micelle-like species, in equilibrium with dissociated forms. In its native form, intra- and inter-molecular disulfide bonds lead to the formation of multimeric species ranging from monomers to decamers. When incubated under conditions of physiological pH and temperature, both reduced and non-reduced kappa-casein form highly structured beta-sheet amyloid fibrils. We investigated whether the precursor to kappa-casein fibril formation is a dissociated state of the protein or its oligomeric micelle-like form. We show that reduced kappa-casein is capable of forming fibrils well below its critical micelle concentration, i.e. at concentrations where only dissociated forms of …
The Effect Of Small Molecules In Modulating The Chaperone Activity Of Alpha B-Crystallin Against Ordered And Disordered Protein Aggregation, Heath Ecroyd, John Carver
The Effect Of Small Molecules In Modulating The Chaperone Activity Of Alpha B-Crystallin Against Ordered And Disordered Protein Aggregation, Heath Ecroyd, John Carver
Heath Ecroyd
Protein aggregation can proceed via disordered or ordered mechanisms, with the latter being associated with amyloid fibril formation, which has been linked to a number of debilitating conditions including Alzheimer's, Parkinson's and Creutzfeldt-Jakob diseases. Small heat-shock proteins (sHsps), such as alpha B-crystallin, act as chaperones to prevent protein aggregation and are thought to play a key role in the prevention of protein-misfolding diseases. In this study, we have explored the potential for small molecules such as arginine and guanidine to affect the chaperone activity of alpha B-crystallin against disordered (amorphous) and ordered (amyloid fibril) forms of protein aggregation. The effect …
The Interaction Of Unfolding Α-Lactalbumin And Malate Dehydrogenase With The Molecular Chaperone Αb-Crystallin: A Light And X-Ray Scattering Investigation, J W. Regini, Heath Ecroyd, Sarah Meehan, Kristen Bremmell, Matthew J. Clarke, Donna Lammie, Tim Wess, John A. Carver
The Interaction Of Unfolding Α-Lactalbumin And Malate Dehydrogenase With The Molecular Chaperone Αb-Crystallin: A Light And X-Ray Scattering Investigation, J W. Regini, Heath Ecroyd, Sarah Meehan, Kristen Bremmell, Matthew J. Clarke, Donna Lammie, Tim Wess, John A. Carver
Heath Ecroyd
Purpose: The molecular chaperone αB-crystallin is found in high concentrations in the lens and is present in all major body tissues. Its structure and the mechanism by which it protects its target protein from aggregating and precipitating are not known. Methods: Dynamic light scattering and X-ray solution scattering techniques were used to investigate structural features of the αB-crystallin oligomer when complexed with target proteins under mild stress conditions, i.e., reduction of α- lactalbumin at 37 °C and malate dehydrogenase when heated at 42 °C. In this investigation, the size, shape and particle distribution of the complexes were determined in real-time …
Analysis Of The Mechanism By Which Calcium Negatively Regulates The Tyrosine Phosphorylation Cascade Associated With Sperm Capacitation, Mark Baker, Louise Hethrington, Heath Ecroyd, Shaun Roman, Robert Aitken
Analysis Of The Mechanism By Which Calcium Negatively Regulates The Tyrosine Phosphorylation Cascade Associated With Sperm Capacitation, Mark Baker, Louise Hethrington, Heath Ecroyd, Shaun Roman, Robert Aitken
Heath Ecroyd
The capacitation of mammalian spermatozoa involves the activation of a cAMP-mediated signal transduction pathway that drives tyrosine phosphorylation via mechanisms that are unique to this cell type. Controversy surrounds the impact of extracellular calcium on this process, with positive and negative effects being recorded in independent publications. We clearly demonstrate that the presence of calcium in the external medium decreases tyrosine phosphorylation in both human and mouse spermatozoa. Under these conditions, a rise in intracellular pH was recorded, however, this event was not responsible for the observed changes in phosphotyrosine expression. Rather, the impact of calcium on tyrosine phosphorylation in …
(-)-Epigallocatechin-3-Gallate (Egcg) Maintains K-Casein In Its Pre-Fibrillar State Without Redirecting Its Aggregation Pathway, Sean A. Hudson, Heath Ecroyd, Francis C. Dehle, Ian F. Musgrave, John Carver
(-)-Epigallocatechin-3-Gallate (Egcg) Maintains K-Casein In Its Pre-Fibrillar State Without Redirecting Its Aggregation Pathway, Sean A. Hudson, Heath Ecroyd, Francis C. Dehle, Ian F. Musgrave, John Carver
Heath Ecroyd
The polyphenol (-)-epigallocatechin-3-gallate (EGCG) has recently attracted much research interest in the field of protein-misfolding diseases because of its potent anti-amyloid activity against amyloid-beta, alpha-synuclein and huntingtin, the amyloid-fibril-forming proteins involved in Alzheimer's, Parkinson's and Huntington's diseases, respectively. EGCG redirects the aggregation of these polypeptides to a disordered off-folding pathway that results in the formation of non-toxic amorphous aggregates. whether this anti-fibril activity is specific to these disease-related target proteins or ismore generic remains to be established. In addition, the mechanism by which EGCG exerts its effects, as with all anti-amyloidogenic polyphenols, remains unclear. To address these aspects, we have …
The Two Faced Nature Of Milk Casein Proteins: Amyloid Fibril Formation And Chaperone-Like Activity, David Thorn, Heath Ecroyd, John Carver
The Two Faced Nature Of Milk Casein Proteins: Amyloid Fibril Formation And Chaperone-Like Activity, David Thorn, Heath Ecroyd, John Carver
Heath Ecroyd
Molecular chaperones are a diverse group of proteins that stabilise partially folded target proteins to prevent their misfolding, aggregation and potential precipitation under conditions of cellular stress, e.g. elevated temperature. Protein aggregation, particularly the formation of highly ordered protein aggregates termed amyloid fibrils, is of considerable research interest because of its intimate association with a wide range of debilitating diseases, including Alzheimer's, Parkinson's and Huntington's diseases and type II diabetes. In this review, we discuss the ability of the milk casein proteins to act in a chaperone-like manner. This property is of biological importance since at least two of the …
New Proteins Identified In Epididymal Fluid From The Platypus (Ornithorhynchus Anatinus), Jean-Louis Dacheux, Francoise Dacheux, Valerie Labas, Heath Ecroyd, Brett Nixon, Russell C. Jones
New Proteins Identified In Epididymal Fluid From The Platypus (Ornithorhynchus Anatinus), Jean-Louis Dacheux, Francoise Dacheux, Valerie Labas, Heath Ecroyd, Brett Nixon, Russell C. Jones
Heath Ecroyd
The platypus epididymal proteome is being studied because epididymal proteins are essential for male fertility in mammals and it is considered that knowledge of the epididymal proteome in an early mammal would be informative in assessing the convergence and divergence of proteins that are important in the function of the mammalian epididymis. Few of the epididymal proteins that have been identified in eutherian mammals were found in platypus caudal epididymal fluid, and the major epididymal proteins in the platypus (PXN-FBPL, SPARC and E-OR20) have never been identified in the epididymis of any other mammal.
Mimicking Phosphorylation Of Alphab-Crystallin Affects Its Chaperone Activity, Heath W. Ecroyd, Sarah Meehan, J Horwitz, Andrew Aquilina, J L Benesch, C V Robinson, Cait Macphee, John Carver
Mimicking Phosphorylation Of Alphab-Crystallin Affects Its Chaperone Activity, Heath W. Ecroyd, Sarah Meehan, J Horwitz, Andrew Aquilina, J L Benesch, C V Robinson, Cait Macphee, John Carver
Heath Ecroyd
No abstract provided.
The Thioflavin T Fluorescence Assay For Amyloid Fibril Detection Can Be Biased By The Presence Of Exogenous Compounds, Sean A. Hudson, Heath Ecroyd, Tak W. Kee, John A. Carver
The Thioflavin T Fluorescence Assay For Amyloid Fibril Detection Can Be Biased By The Presence Of Exogenous Compounds, Sean A. Hudson, Heath Ecroyd, Tak W. Kee, John A. Carver
Heath Ecroyd
Thioflavin T (ThT) dye fluorescence is used regularly to quantify the formation and inhibition of amyloid fibrils in the presence of anti-amyloidogenic compounds such as polyphenols. However, in this study, it was shown, using three polyphenolics (curcumin, quercetin and resveratrol), that ThT fluorescence should be used with caution in the presence of such exogenous compounds. The strong absorptive and fluorescent properties of quercetin and curcumin were found to significantly bias the ThT fluorescence readings in both in situ real-time ThT assays and single time-point dilution ThT-type assays. The presence of curcumin at concentrations as low as 0.01 and 1 uM …
Unraveling The Mysteries Of Protein Folding And Misfolding, Heath Ecroyd, John A. Carver
Unraveling The Mysteries Of Protein Folding And Misfolding, Heath Ecroyd, John A. Carver
Heath Ecroyd
This mini-review focuses on the processes and consequences of protein folding and misfolding. The latter process often leads to protein aggregation and precipitation with the aggregates adopting either highly ordered (amyloid fibril) or disordered (amorphous) forms. In particular, the amyloid fibril is discussed because this form has gained considerable notoriety due to its close links to a variety of debilitating diseases including Alzheimer's, Parkinson's, Huntington's, and Creutzfeldt-Jakob diseases, and type-II diabetes. In each of these diseases a different protein forms fibrils, yet the fibrils formed have a very similar structure. The mechanism by which fibrils form, fibril structure, and the …
Crystallin Proteins And Amyloid Fibrils, Heath Ecroyd, John A. Carver
Crystallin Proteins And Amyloid Fibrils, Heath Ecroyd, John A. Carver
Heath Ecroyd
Improper protein folding (misfolding) can lead to the formation of disordered (amorphous) or ordered (amyloid fibril) aggregates. The major lens protein, alpha-crystallin, is a member of the small heat-shock protein (sHsp) family of intracellular molecular chaperone proteins that prevent protein aggregation. Whilst the chaperone activity of sHsps against amorphously aggregating proteins has been well studied, its action against fibril-forming proteins has received less attention despite the presence of sHsps in deposits found in fibril-associated diseases (e.g. Alzheimer's and Parkinson's). In this review, the literature on the interaction of alpha B-crystallin and other sHsps with fibril-forming proteins is summarized. In particular, …