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Articles 1 - 30 of 35
Full-Text Articles in Social and Behavioral Sciences
The Influence Of A Short-Stay International Trip On Chaperones’ Attitudes Toward Traveling Students, Co-Chaperones, And The Destination Culture: A Case Study, Frederick N. Mbayu
The Influence Of A Short-Stay International Trip On Chaperones’ Attitudes Toward Traveling Students, Co-Chaperones, And The Destination Culture: A Case Study, Frederick N. Mbayu
Doctor of Education (Ed.D)
Chaperones are adults who accompany, look after, and supervise traveling students. This case study examined the influence of an urban middle school short-stay international trip to France on chaperones’ perceptions and attitudes toward traveling students, co-chaperones, and the destination culture. Five chaperones on spring break trips from 2014 to 2017 provided data during individual ex post facto semi-structured interviews. Trip-related documents and trip vendor participant online accounts were analyzed to corroborate and augment the interview data. Participants developed a positive view of the traveling students after traveling together for ten days. Chaperones increased their understanding of diversity, developed a deeper …
Patients' Attitudes Towards Chaperone Use For Intimate Physical Examinations In General Practice, Lucie C. Stanford, Andrew D. Bonney, Rowena G. Ivers, Judy Mullan, Warren C. Rich, Bridget R. Dijkmans-Hadley
Patients' Attitudes Towards Chaperone Use For Intimate Physical Examinations In General Practice, Lucie C. Stanford, Andrew D. Bonney, Rowena G. Ivers, Judy Mullan, Warren C. Rich, Bridget R. Dijkmans-Hadley
Faculty of Science, Medicine and Health - Papers: part A
BACKGROUND: The objective of this article is to investigate patients' attitudes to the use of chaperones for intimate physical examinations (IPEs) in a sample of Australian general practices. METHODS: A cross-sectional survey of adult patients from 13 randomly selected general practices in regional New South Wales was conducted between September and November 2012. Generalised linear mixed models were used for analysis. RESULTS: Of 780 surveys distributed, 687 (88%) were returned; the age range was 18-91 years and 356 (52%) were from female patients. Most women had never had a chaperone present for a Papanicolaou (Pap) smear (82.6%). Between 23% and …
Structural Characterization Of Clusterin-Chaperone Client Protein Complexes, Amy Wyatt, Justin Yerbury, Mark Wilson
Structural Characterization Of Clusterin-Chaperone Client Protein Complexes, Amy Wyatt, Justin Yerbury, Mark Wilson
Mark R Wilson
Clusterin (CLU) is a potent extracellular chaperone that inhibits protein aggregation and precipitation otherwise caused by physical or chemical stresses (e.g. heat, reduction). This action involves CLU forming soluble high molecular weight (HMW) complexes with the client protein. Other than their unquantified large size, the physical characteristics of these complexes were previously unknown. In this study, HMW CLU-citrate synthase (CS), HMW CLU-fibrinogen (FGN), and HMW CLU-glutathione S-transferase (GST) complexes were generated in vitro, and their structures studied using size exclusion chromatography (SEC), ELISA, SDS-PAGE, dynamic light scattering (DLS), bisANS fluorescence, and circular dichroism spectrophotometry (CD). Densitometry of …
Identification Of Human Plasma Proteins As Major Clients For The Extracellular Chaperone Clusterin, Amy R. Wyatt, Mark R. Wilson
Identification Of Human Plasma Proteins As Major Clients For The Extracellular Chaperone Clusterin, Amy R. Wyatt, Mark R. Wilson
Mark R Wilson
Clusterin (CLU) is an extracellular chaperone that is likely to play an important role in protein folding quality control. This study identified three deposition disease-associated proteins as major plasma clients for clusterin by studying CLU-client complexes formed in response to physiologically relevant stress (shear stress, similar to 36 dynes/cm(2) at 37 degrees C). Analysis of plasma samples by size exclusion chromatography indicated that (i) relative to control plasma, stressed plasma contained proportionally more soluble protein species of high molecular weight, and (ii) high molecular weight species were far more abundant when proteins purified by anti-CLU immunoaffinity chromatography from stressed plasma …
Binding Of The Molecular Chaperone Alphab-Crystallin To Abeta Amyloid Fibrils Inhibits Fibril Elongation, Sarah L. Shammas, Christopher A. Waudby, Shuyu Wang, Alexander K. Buell, Tuomas P. Knowles, Heath W. Ecroyd, Mark E. Welland, John A. Carver, Christopher M. Dobson, Sarah Meehan
Binding Of The Molecular Chaperone Alphab-Crystallin To Abeta Amyloid Fibrils Inhibits Fibril Elongation, Sarah L. Shammas, Christopher A. Waudby, Shuyu Wang, Alexander K. Buell, Tuomas P. Knowles, Heath W. Ecroyd, Mark E. Welland, John A. Carver, Christopher M. Dobson, Sarah Meehan
Heath Ecroyd
The molecular chaperone αB-crystallin is a small heat-shock protein that is upregulated in response to a multitude of stress stimuli, and is found colocalized with Aβ amyloid fibrils in the extracellular plaques that are characteristic of Alzheimer's disease. We investigated whether this archetypical small heat-shock protein has the ability to interact with Aβ fibrils in vitro. We find that αB-crystallin binds to wild-type Aβ42 fibrils with micromolar affinity, and also binds to fibrils formed from the E22G Arctic mutation of Aβ42. Immunoelectron microscopy confirms that binding occurs along the entire length and ends of the fibrils. Investigations into the effect …
Nmr Spectroscopy Of 14-3-3zeta Reveals A Flexible C-Terminal Extension: Differentiation Of The Chaperone And Phosphoserine-Binding Activities Of 14-3-3zeta, H Fu, Danielle Williams, Heath Ecroyd, John Carver, Lixin Zhang, Huanqin Dai, Joanna Woodcock, K Goodwin
Nmr Spectroscopy Of 14-3-3zeta Reveals A Flexible C-Terminal Extension: Differentiation Of The Chaperone And Phosphoserine-Binding Activities Of 14-3-3zeta, H Fu, Danielle Williams, Heath Ecroyd, John Carver, Lixin Zhang, Huanqin Dai, Joanna Woodcock, K Goodwin
Heath Ecroyd
Intracellular 14-3-3 proteins bind to many proteins, via a specific phosphoserine motif, regulating diverse cellular tasks including cell signalling and disease progression. The 14-3-3 isoform is a molecular chaperone, preventing the stressinduced aggregation of target proteins in a manner comparable with that of the unrelated sHsps (small heat-shock proteins). 1H-NMR spectroscopy revealed the presence of a flexible and unstructured C-terminal extension, 12 amino acids in length, which protrudes from the domain core of 14-3-3 and is similar in structure and length to the C-terminal extension of mammalian sHsps. The extension stabilizes 14-3-3, but has no direct role in chaperone action. …
Enhanced Molecular Chaperone Activity Of The Small Heat-Shock Protein Alphab-Cystallin Following Covalent Immobilization Onto A Solid-Phase Support, V Bellotti, Heath Ecroyd, J Carver, H J Griesser, B Thierry, J G Shapter, S S Griesser, S Giorgetti, M R Nussio, J A Gerrard, J Garvey
Enhanced Molecular Chaperone Activity Of The Small Heat-Shock Protein Alphab-Cystallin Following Covalent Immobilization Onto A Solid-Phase Support, V Bellotti, Heath Ecroyd, J Carver, H J Griesser, B Thierry, J G Shapter, S S Griesser, S Giorgetti, M R Nussio, J A Gerrard, J Garvey
Heath Ecroyd
The well-characterized small heat-shock protein, alphaB-crystallin, acts as a molecular chaperone by interacting with unfolding proteins to prevent their aggregation and precipitation. Structural perturbation (e.g., partial unfolding) enhances the in vitro chaperone activity of alphaB-crystallin. Proteins often undergo structural perturbations at the surface of a synthetic material, which may alter their biological activity. This study investigated the activity of alphaB-crystallin when covalently bound to a support surface; alphaB-crystallin was immobilized onto a range of solid material surfaces, and its characteristics and chaperone activity were assessed. Immobilization was achieved via a plasma-deposited thin polymeric interlayer containing aldehyde surface groups and reductive …
Evidence For Specific Subunit Distribution And Interactions In The Quaternary Structure Of Α-Crystallin, Amie M. Morris, J. Andrew Aquilina
Evidence For Specific Subunit Distribution And Interactions In The Quaternary Structure Of Α-Crystallin, Amie M. Morris, J. Andrew Aquilina
J. A. Aquilina
The quaternary structure of α-crystallin is dynamic, a property which has thwarted crystallographic efforts towards structural characterization. In this study, we have used collision-induced dissociation mass spectrometry to examine the architecture of the polydisperse assemblies of α-crystallin. For total α-crystallin isolated directly from fetal calf lens using size-based chromatography, the αB-crystallin subunit was found to be preferentially dissociated from the oligomers, despite being significantly less abundant overall than the αA-crystallin subunits. Furthermore, upon mixing molar equivalents of purified αA- and αB-crystallin, the levels of their dissociation were found to decrease and increase, respectively, with time. Interestingly though, dissociation of subunits …
Effects Of Glycosylation On The Structure And Function Of The Extracellular Chaperone Clusterin, Elise Stewart, Andrew Aquilina, Simon B Easterbrook-Smith, D Murphy-Durland, C Jacobsen, S Moestrup, Mark Wilson
Effects Of Glycosylation On The Structure And Function Of The Extracellular Chaperone Clusterin, Elise Stewart, Andrew Aquilina, Simon B Easterbrook-Smith, D Murphy-Durland, C Jacobsen, S Moestrup, Mark Wilson
J. A. Aquilina
Clusterin is the first well characterized, constitutively secreted extracellular chaperone that binds to exposed regions of hydrophobicity on non-native proteins. It may help control the folding state of extracellular proteins by targeting them for receptor-mediated endocytosis and intracellular lysosomal degradation. A notable feature of secreted clusterin is its heavy glycosylation. Although carbohydrate comprises approximately 20−25% of the total mass of the mature molecule, its function is unknown. Results from the current study demonstrate that deglycosylation of human serum clusterin had little effect on its overall secondary structure content but produced a small increase in solvent-exposed hydrophobicity and enhanced the propensity …
Corrigendum To ‘‘The Chaperone Action Of Bovine Milk As1- And As2-Caseins And Their Associated Form As-Casein’’ [Arch. Biochem. Biophys. 510 (2011) 42–52], Teresa M. Treweek, David C. Thorn, William E. Price, John A. Carver
Corrigendum To ‘‘The Chaperone Action Of Bovine Milk As1- And As2-Caseins And Their Associated Form As-Casein’’ [Arch. Biochem. Biophys. 510 (2011) 42–52], Teresa M. Treweek, David C. Thorn, William E. Price, John A. Carver
William E. Price
No abstract provided.
The Small Heat-Shock Protein Αb-Crystallin Uses Different Mechanisms Of Chaperone Action To Prevent The Amorphous Versus Fibrillar Aggregation Of Α-Lactalbumin, Melissa Kulig, Heath Ecroyd
The Small Heat-Shock Protein Αb-Crystallin Uses Different Mechanisms Of Chaperone Action To Prevent The Amorphous Versus Fibrillar Aggregation Of Α-Lactalbumin, Melissa Kulig, Heath Ecroyd
Faculty of Science, Medicine and Health - Papers: part A
Stress conditions can destabilize proteins, promoting them to unfold and adopt intermediately folded states. Partially folded protein intermediates are unstable and prone to aggregation down off-folding pathways leading to the formation of either amorphous or amyloid fibril aggregates. The sHsp (small heat-shock protein) αB-crystallin acts as a molecular chaperone to prevent both amorphous and fibrillar protein aggregation; however, the precise molecular mechanisms behind its chaperone action are incompletely understood. To investigate whether the chaperone activity of αB-crystallin is dependent upon the form of aggregation (amorphous compared with fibrillar), bovine α-lactalbumin was developed as a model target protein that could be …
Small Heat Shock Protein Activity Is Regulated By Variable Oligomeric Substructure, J. L. Benesch, M. Ayoub, C. V. Robinson, J. A. Aquilina
Small Heat Shock Protein Activity Is Regulated By Variable Oligomeric Substructure, J. L. Benesch, M. Ayoub, C. V. Robinson, J. A. Aquilina
J. A. Aquilina
The alpha-crystallins are members of the small heat shock protein (sHSP) family of molecular chaperones which have evolved to minimize intracellular protein aggregation, however they are also implicated in a number of protein deposition diseases. In this study we have employed novel mass spectrometry techniques to investigate the changes in quaternary structure associated with this switch from chaperone to adjuvant of aggregation. We have replicated the oligomeric rearrangements observed for in vivo disease-related modifications, without altering the protein sequence, by refolding the alpha-crystallins in vitro. This refolding results in a loss of dimeric substructure concomitant with an augmentation of substrate …
Evidence For Specific Subunit Distribution And Interactions In The Quaternary Structure Of Α-Crystallin, Amie M. Morris, J. Andrew Aquilina
Evidence For Specific Subunit Distribution And Interactions In The Quaternary Structure Of Α-Crystallin, Amie M. Morris, J. Andrew Aquilina
J. A. Aquilina
The quaternary structure of α-crystallin is dynamic, a property which has thwarted crystallographic efforts towards structural characterization. In this study, we have used collision-induced dissociation mass spectrometry to examine the architecture of the polydisperse assemblies of α-crystallin. For total α-crystallin isolated directly from fetal calf lens using size-based chromatography, the αB-crystallin subunit was found to be preferentially dissociated from the oligomers, despite being significantly less abundant overall than the αA-crystallin subunits. Furthermore, upon mixing molar equivalents of purified αA- and αB-crystallin, the levels of their dissociation were found to decrease and increase, respectively, with time. Interestingly though, dissociation of subunits …
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
J. A. Aquilina
No abstract provided.
The Extracellular Chaperone Clusterin Sequesters Oligomeric Forms Of The Amyloid-Beta 1-40 Peptide, Priyanka Narayan, Angel Orte, Richard W. Clarke, Benedetta Bolognesi, Sharon Hook, Kristina A. Ganzinger, Sarah Meehan, Mark R. Wilson, Christopher M. Dobson, David Klenerman
The Extracellular Chaperone Clusterin Sequesters Oligomeric Forms Of The Amyloid-Beta 1-40 Peptide, Priyanka Narayan, Angel Orte, Richard W. Clarke, Benedetta Bolognesi, Sharon Hook, Kristina A. Ganzinger, Sarah Meehan, Mark R. Wilson, Christopher M. Dobson, David Klenerman
Faculty of Science - Papers (Archive)
In recent genome-wide association studies, the extracellular chaperone protein, clusterin, has been identified as a newly-discovered risk factor in Alzheimer's disease. We have examined the interactions between human clusterin and the Alzheimer's disease-associated amyloid-β 1-40 peptide (Aβ 1-40), which is prone to aggregate into an ensemble of oligomeric intermediates implicated in both the proliferation of amyloid fibrils and in neuronal toxicity. Using highly sensitive single-molecule fluorescence methods, we have found that Aβ 1-40 forms a heterogeneous distribution of small oligomers (from dimers to 50-mers), all of which interact with clusterin to form long-lived, stable complexes. Consequently, clusterin is able …
The Extracellular Chaperone Clusterin Sequesters Oligomeric Forms Of The Amyloid-Beta 1-40 Peptide, Priyanka Narayan, Angel Orte, Richard Clarke, Benedetta Bolognesi, Sharon Hook, Kristina Ganzinger, Sarah Meehan, Mark Wilson, Christopher Dobson, David Klenerman
The Extracellular Chaperone Clusterin Sequesters Oligomeric Forms Of The Amyloid-Beta 1-40 Peptide, Priyanka Narayan, Angel Orte, Richard Clarke, Benedetta Bolognesi, Sharon Hook, Kristina Ganzinger, Sarah Meehan, Mark Wilson, Christopher Dobson, David Klenerman
Mark R Wilson
In recent genome-wide association studies, the extracellular chaperone protein, clusterin, has been identified as a newly-discovered risk factor in Alzheimer's disease. We have examined the interactions between human clusterin and the Alzheimer's disease-associated amyloid-β 1-40 peptide (Aβ 1-40), which is prone to aggregate into an ensemble of oligomeric intermediates implicated in both the proliferation of amyloid fibrils and in neuronal toxicity. Using highly sensitive single-molecule fluorescence methods, we have found that Aβ 1-40 forms a heterogeneous distribution of small oligomers (from dimers to 50-mers), all of which interact with clusterin to form long-lived, stable complexes. Consequently, clusterin is able to …
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 …
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 …
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.
Corrigendum To ‘‘The Chaperone Action Of Bovine Milk As1- And As2-Caseins And Their Associated Form As-Casein’’ [Arch. Biochem. Biophys. 510 (2011) 42–52], Teresa M. Treweek, David C. Thorn, William E. Price, John A. Carver
Corrigendum To ‘‘The Chaperone Action Of Bovine Milk As1- And As2-Caseins And Their Associated Form As-Casein’’ [Arch. Biochem. Biophys. 510 (2011) 42–52], Teresa M. Treweek, David C. Thorn, William E. Price, John A. Carver
Faculty of Science - Papers (Archive)
No abstract provided.
Binding Of The Molecular Chaperone Alphab-Crystallin To Abeta Amyloid Fibrils Inhibits Fibril Elongation, Sarah L. Shammas, Christopher A. Waudby, Shuyu Wang, Alexander K. Buell, Tuomas P. Knowles, Heath W. Ecroyd, Mark E. Welland, John A. Carver, Christopher M. Dobson, Sarah Meehan
Binding Of The Molecular Chaperone Alphab-Crystallin To Abeta Amyloid Fibrils Inhibits Fibril Elongation, Sarah L. Shammas, Christopher A. Waudby, Shuyu Wang, Alexander K. Buell, Tuomas P. Knowles, Heath W. Ecroyd, Mark E. Welland, John A. Carver, Christopher M. Dobson, Sarah Meehan
Faculty of Science - Papers (Archive)
The molecular chaperone αB-crystallin is a small heat-shock protein that is upregulated in response to a multitude of stress stimuli, and is found colocalized with Aβ amyloid fibrils in the extracellular plaques that are characteristic of Alzheimer's disease. We investigated whether this archetypical small heat-shock protein has the ability to interact with Aβ fibrils in vitro. We find that αB-crystallin binds to wild-type Aβ42 fibrils with micromolar affinity, and also binds to fibrils formed from the E22G Arctic mutation of Aβ42. Immunoelectron microscopy confirms that binding occurs along the entire length …
Identification Of Human Plasma Proteins As Major Clients For The Extracellular Chaperone Clusterin, Amy R. Wyatt, Mark R. Wilson
Identification Of Human Plasma Proteins As Major Clients For The Extracellular Chaperone Clusterin, Amy R. Wyatt, Mark R. Wilson
Faculty of Science - Papers (Archive)
Clusterin (CLU) is an extracellular chaperone that is likely to play an important role in protein folding quality control. This study identified three deposition disease-associated proteins as major plasma clients for clusterin by studying CLU-client complexes formed in response to physiologically relevant stress (shear stress, similar to 36 dynes/cm(2) at 37 degrees C). Analysis of plasma samples by size exclusion chromatography indicated that (i) relative to control plasma, stressed plasma contained proportionally more soluble protein species of high molecular weight, and (ii) high molecular weight species were far more abundant when proteins purified by anti-CLU immunoaffinity chromatography from stressed plasma …
Evidence For Specific Subunit Distribution And Interactions In The Quaternary Structure Of Α-Crystallin, Amie M. Morris, J. Andrew Aquilina
Evidence For Specific Subunit Distribution And Interactions In The Quaternary Structure Of Α-Crystallin, Amie M. Morris, J. Andrew Aquilina
Faculty of Science - Papers (Archive)
The quaternary structure of α-crystallin is dynamic, a property which has thwarted crystallographic efforts towards structural characterization. In this study, we have used collision-induced dissociation mass spectrometry to examine the architecture of the polydisperse assemblies of α-crystallin. For total α-crystallin isolated directly from fetal calf lens using size-based chromatography, the αB-crystallin subunit was found to be preferentially dissociated from the oligomers, despite being significantly less abundant overall than the αA-crystallin subunits. Furthermore, upon mixing molar equivalents of purified αA- and αB-crystallin, the levels of their dissociation were found to decrease and increase, respectively, with time. Interestingly though, dissociation of subunits …
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
Faculty of Science - Papers (Archive)
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 …
Structural Characterization Of Clusterin-Chaperone Client Protein Complexes, Amy R. Wyatt, Justin J. Yerbury, Mark R. Wilson
Structural Characterization Of Clusterin-Chaperone Client Protein Complexes, Amy R. Wyatt, Justin J. Yerbury, Mark R. Wilson
Faculty of Science - Papers (Archive)
Clusterin (CLU) is a potent extracellular chaperone that inhibits protein aggregation and precipitation otherwise caused by physical or chemical stresses (e.g. heat, reduction). This action involves CLU forming soluble high molecular weight (HMW) complexes with the client protein. Other than their unquantified large size, the physical characteristics of these complexes were previously unknown. In this study, HMW CLU-citrate synthase (CS), HMW CLU-fibrinogen (FGN), and HMW CLU-glutathione S-transferase (GST) complexes were generated in vitro, and their structures studied using size exclusion chromatography (SEC), ELISA, SDS-PAGE, dynamic light scattering (DLS), bisANS fluorescence, and circular dichroism spectrophotometry (CD). Densitometry of …
The Chaperone Action Of Clusterin And Its Putative Role In Quality Control Of Extracellular Protein Folding, Amy Wyatt, Justin Yerbury, Stephen Poon, Rebecca Dabbs, Mark Wilson
The Chaperone Action Of Clusterin And Its Putative Role In Quality Control Of Extracellular Protein Folding, Amy Wyatt, Justin Yerbury, Stephen Poon, Rebecca Dabbs, Mark Wilson
Mark R Wilson
The function(s) of clusterin may depend upon its topological location. A variety of intracellular "isoforms" of clusterin have been reported but further work is required to better define their identity. The secreted form of clusterin has a potent ability to inhibit both amorphous and amyloid protein aggregation. In the case of amorphous protein aggregation, clusterin forms stable, soluble high-molecular-weight complexes with misfolded client proteins. Clusterin expression is increased during many types of physiological and pathological stresses and is thought to function as an extracellular chaperone (EC). The pathology of a variety of serious human diseases is thought to arise as …
Small Heat Shock Protein Activity Is Regulated By Variable Oligomeric Substructure, J. L. Benesch, M. Ayoub, C. V. Robinson, J. A. Aquilina
Small Heat Shock Protein Activity Is Regulated By Variable Oligomeric Substructure, J. L. Benesch, M. Ayoub, C. V. Robinson, J. A. Aquilina
Faculty of Science - Papers (Archive)
The alpha-crystallins are members of the small heat shock protein (sHSP) family of molecular chaperones which have evolved to minimize intracellular protein aggregation, however they are also implicated in a number of protein deposition diseases. In this study we have employed novel mass spectrometry techniques to investigate the changes in quaternary structure associated with this switch from chaperone to adjuvant of aggregation. We have replicated the oligomeric rearrangements observed for in vivo disease-related modifications, without altering the protein sequence, by refolding the alpha-crystallins in vitro. This refolding results in a loss of dimeric substructure concomitant with an augmentation of substrate …
Protease Activation Of A2-Macroglobulin Modulates A Chaperone-Like Action With Broad Specificity, Katie French, Justin Yerbury, Mark Wilson
Protease Activation Of A2-Macroglobulin Modulates A Chaperone-Like Action With Broad Specificity, Katie French, Justin Yerbury, Mark Wilson
Mark R Wilson
α2-Macroglobulin (α2M) is a major human blood glycoprotein best known for its ability to inhibit a broad spectrum of proteases by a unique trapping method. This action induces an “activated” conformation of α2M with an exposed binding site for the low density lipoprotein receptor, facilitating clearance of α2M-protease complexes from the body. This report establishes that protease activation also modulates a potent chaperone-like action of α2M which has broad specificity for proteins partly unfolded as a result of heat or oxidative stress. Protease-mediated activation of α2M abolishes its chaperone-like activity. However, native α2M is able to form soluble complexes with …
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
Faculty of Science - Papers (Archive)
No abstract provided.