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Full-Text Articles in Medicine and Health Sciences

Ip And The Global Public Interest: Challenges And Opportunities, Jon R. Cavicchi, Stanley P. Kowalski Jan 2007

Ip And The Global Public Interest: Challenges And Opportunities, Jon R. Cavicchi, Stanley P. Kowalski

Law Faculty Scholarship

[Excerpt from article] Intellectual property (IP) capacity is essential for economic development, particularly as countries transition into the higher technology sectors, for example biotechnology. For developing countries, a commitment to minimal IP rights protection will determine inclusion in the World Trade Organization (WTO), facilitate access to foreign-direct investment, and accelerate economic development. However, on a more fundamental level, capacity in IP management will affect whether a country can provide basic health and nutritional needs for its citizens. For example, sustainable food security presents a serious challenge in many developing countries; as their economies rapidly emerge, urban centers expand, arable land …


Retrocyclin Rc-101 Overcomes Cationic Mutations On The Heptad Repeat 2 Of Hiv-1 Gp41, Christopher Fuhrman Jan 2007

Retrocyclin Rc-101 Overcomes Cationic Mutations On The Heptad Repeat 2 Of Hiv-1 Gp41, Christopher Fuhrman

Electronic Theses and Dissertations

Retrocyclin RC-101, a θ-defensin with lectin-like properties, potently inhibits infection by many HIV-1 subtypes by binding to the heptad repeat (HR)-2 region of gp41 and preventing six-helix bundle formation. In the present study, we used in silico computational exploration to identify residues of HR2 that interacted with RC-101 and then analyzed the HIV-1 Sequence Database at LANL for residue variations in the HR1 and HR2 segments that could plausibly impart in vivo resistance. Docking RC-101 to gp41 peptides in silico confirmed its strong preference for HR2 over HR1, and implicated residues crucial for its ability to bind HR2. We mutagenized …


Activating Gene Expression In Mammalian Cells With Promoter-Targeted Duplex Rnas, Daniel Hardy Jan 2007

Activating Gene Expression In Mammalian Cells With Promoter-Targeted Duplex Rnas, Daniel Hardy

Data and Test Instruments

No abstract provided.


Benjamin In Paris: Weak Messianism And Memories Of The Oppressed, Jules Simon Jan 2007

Benjamin In Paris: Weak Messianism And Memories Of The Oppressed, Jules Simon

Selected Works Temporary Series

No abstract provided.


Public Health Performance, F. Douglas Scutchfield Md Jan 2007

Public Health Performance, F. Douglas Scutchfield Md

Preventive Medicine and Environmental Health Presentations

No abstract provided.


An Hsus Report: Human Health Implications Of U.S. Live Bird Markets In The Spread Of Avian Influenza, The Humane Society Of The United States Jan 2007

An Hsus Report: Human Health Implications Of U.S. Live Bird Markets In The Spread Of Avian Influenza, The Humane Society Of The United States

Impact of Animal Agriculture

After millions of years of existing as a harmless infection of aquatic birds, some strains of avian flu have developed the ability to mutate into highly pathogenic forms that may not only be deadly for birds, but potentially more dangerous for humans as well. Experts from the World Health Organization, the World Organization for Animal Health, and the Food and Agriculture Organization of the United Nations have joined leading scientists in implicating industrialized poultry production for providing fertile ground for the transformation of benign bird flu into highly pathogenic strains.

Live bird markets can be the conduit by which waterfowl …


Their Bugs Are Worse Than Their Bite: Emerging Infectious Disease And The Human-Animal Interface, Michael Greger Jan 2007

Their Bugs Are Worse Than Their Bite: Emerging Infectious Disease And The Human-Animal Interface, Michael Greger

State of the Animals 2007

In the twenty-five years since that announcement, what we now know as AIDS has killed 20 million people (National AIDS Trust 2005). Where did the AIDS virus— and other emerging diseases, such as severe acute respiratory syndrome (SARS), Ebola, mad cow— come from?


The Human/Animal Interface: Emergence And Resurgence Of Zoonotic Infectious Diseases, Michael Greger Jan 2007

The Human/Animal Interface: Emergence And Resurgence Of Zoonotic Infectious Diseases, Michael Greger

Transgenesis Collection

Emerging infectious diseases, most of which are considered zoonotic in origin, continue to exact a significant toll on society. The origins of major human infectious diseases are reviewed and the factors underlying disease emergence explored. Anthropogenic changes, largely in land use and agriculture, are implicated in the apparent increased frequency of emergence and reemergence of zoonoses in recent decades. Special emphasis is placed on the pathogen with likely the greatest zoonotic potential, influenzavirus A.


A Holistic Approach To Taking Research Animal Suffering Seriously, Martin Stephens, Kathleen Conlee Jan 2007

A Holistic Approach To Taking Research Animal Suffering Seriously, Martin Stephens, Kathleen Conlee

Experimentation Collection

It is widely agreed, and often legally required, that distress and pain in research animals should be minimized--for the sake of animal welfare, ethical obligation, and public concern, as well as scientific quality. As testimony to the importance of distress and pain to stakeholders interested in research animals, many countries compile and publish annual statistics documenting overall patterns and trends on distress and pain in research animals.

We argue for a holistic approach to minimizing research animal suffering, with all relevant parties sharing in this responsibility. Researchers, laboratory personnel, oversight committees, and facility administrators are central to day-to-day animal care. …


Of Mice And Men, Bernard E. Rollin Jan 2007

Of Mice And Men, Bernard E. Rollin

Experimentation Collection

No abstract provided.


Chimpanzee Research: An Examination Of Its Contribution To Biomedical Knowledge And Efficacy In Combating Human Diseases, Jarrod Bailey, Jonathan Balcombe, Theodora Capaldo Jan 2007

Chimpanzee Research: An Examination Of Its Contribution To Biomedical Knowledge And Efficacy In Combating Human Diseases, Jarrod Bailey, Jonathan Balcombe, Theodora Capaldo

Experimentation Collection

Research on captive chimpanzees incurs considerable animal welfare, ethical and financial costs. Advocates of such research claim these costs are outweighed by substantial advancements in biomedical knowledge, and that the genetic similarity of chimpanzees to humans enables the former to make critical contributions to preventing, diagnosing and combating human diseases. To assess these claims, we examined the disciplines investigated in 749 studies of captive chimpanzees published from 1995-2004 inclusive, and subjected 95 randomly selected papers to a detailed citation analysis:

49.5% (47/95) of papers had not been cited at the time of this study; 38.5% (34/95) were cited by 116 …


Cranial Duplication (Dicephalus) In A Lamb, Özkan Ünver, Mehmet Kilinç, Ni̇hat Özyurtlu Jan 2007

Cranial Duplication (Dicephalus) In A Lamb, Özkan Ünver, Mehmet Kilinç, Ni̇hat Özyurtlu

Turkish Journal of Veterinary & Animal Sciences

A case of cranial duplication (Dicephalus) was described in a newborn lamb. The radiographic and macroscopic examination was performed after the cesarean section. The lamb´s heads were not completely separated. A complete nasopharynx, oropharynx, laringopharynx, and normal tongue were present in each head. The lamb died shortly after birth.


Erythropoietin Improves Skeletal Muscle Microcirculation And Tissue Bioenergetics In A Mouse Sepsis Model, Raymod Kao, Anargyros Xenocostas, Tao Rui, Weixiong Huang, James Rose, Claudio M. Martin Jan 2007

Erythropoietin Improves Skeletal Muscle Microcirculation And Tissue Bioenergetics In A Mouse Sepsis Model, Raymod Kao, Anargyros Xenocostas, Tao Rui, Weixiong Huang, James Rose, Claudio M. Martin

Anatomy and Cell Biology Publications

Introduction The relationship between oxygen delivery and consumption in sepsis is impaired, suggesting a microcirculatory perfusion defect. Recombinant human erythropoietin ( rHuEPO) regulates erythropoiesis and also exerts complex actions promoting the maintenance of homeostasis of the organism under stress. The objective of this study was to test the hypothesis that rHuEPO could improve skeletal muscle capillary perfusion and tissue oxygenation in sepsis. Methods Septic mice in three experiments received rHu-EPO 400 U/kg subcutaneously 18 hours after cecal ligation and perforation ( CLP). The first experiment measured the acute effects of rHuEPO on hemodynamics, blood counts, and arterial lactate level. The …


Role Of Mhc Antigens And Immunoregulation In Graft Survival In Autoimmunity, Bhagirath Singh Jan 2007

Role Of Mhc Antigens And Immunoregulation In Graft Survival In Autoimmunity, Bhagirath Singh

Microbiology & Immunology Publications

Using a syngeneic islet transplantation model system we have showed that in autoimmune type 1 diabetes transplanted islets are destroyed by the host immune system unless the transplanted islets lack class I major histocompatibility complex (MHC) molecules. Alternatively, immunomodulation of the host by induction of regulatory T cells prevented the destruction of autologous islet graft. We conclude that these approaches will allow successful transplantation of autologous islets derived from the host by stem cell or other technology without immunosuppression to reverse autoimmune type 1 diabetes.


The Impact Of Nutrition On Academic Achievement, Julie A. Long Jan 2007

The Impact Of Nutrition On Academic Achievement, Julie A. Long

Graduate Research Papers

The recent increase of obesity and malnourishment among students has prompted many researchers to question the effects of such lifestyles on the students' health and academic areas. Many factors are to be associated with the lack of knowledge and initiative to make amendments within the system. In addition, many steps can be taken to implement the correct changes. This paper outlines the causes of malnutrition, the affects of poor nutrients, the vitality of specific nutrient, and ways to help the problems cease. Attention to the strong research and statistics, leads to transformation of the traditions and barriers of individuals choosing …


An Ectopic Case Of Psoroptes Cuniculi Infestation In A Pet Rabbit, Abuzer Acar, Ari̇f Kurtdede, Kerem Ural, Cenker Çağri Cingi, Mehmet Çağri Karakurum, Buğrahan Beki̇r Yağci, Bariş Sari Jan 2007

An Ectopic Case Of Psoroptes Cuniculi Infestation In A Pet Rabbit, Abuzer Acar, Ari̇f Kurtdede, Kerem Ural, Cenker Çağri Cingi, Mehmet Çağri Karakurum, Buğrahan Beki̇r Yağci, Bariş Sari

Turkish Journal of Veterinary & Animal Sciences

A 2-year-old female New Zealand rabbit was admitted to Ankara University Veterinary Faculty, Department of Internal Medicine. Upon physical examination crustaceous auricular lesions, and erythematous and exudative pruritic skin lesions, both on the ventral abdomen and on extremities were detected. Microscopic examination of skin scrapings taken from pinnae and hair plucked from the ventral abdominal region revealed the presence of Psoroptes cuniculi. The ventral abdominal localization of P. cuniculi was evaluated as an ectopic infestation. Despite the injection of ivermectin 400 µg/kg and daily supportive therapy the rabbit died on the fifth day of hospitalization.


The Birth Of A Wild Ass (Equus Hemionus Khur) In India’S Little Rann Of Kutch, Gertrud Neumann-Denzau Jan 2007

The Birth Of A Wild Ass (Equus Hemionus Khur) In India’S Little Rann Of Kutch, Gertrud Neumann-Denzau

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

The birth of a wild ass was completely described and photographed in the wild for the first time. It happened in the daytime, in the open desert, and in the vicinity of other wild asses. The mother isolated her foal afterwards for an entire day. After birthing she drove away her male yearling, which did not join her any longer from this moment on.


Poxviral B1 Kinase Overcomes Barrier To Autointegration Factor, A Host Defense Against Virus Replication, Matthew S. Wiebe, Paula Traktman Jan 2007

Poxviral B1 Kinase Overcomes Barrier To Autointegration Factor, A Host Defense Against Virus Replication, Matthew S. Wiebe, Paula Traktman

Nebraska Center for Virology: Faculty Publications

Barrier to autointegration factor (BAF) is a DNA-binding protein found in the nucleus and cytoplasm of eukaryotic cells that functions to establish nuclear architecture during mito-sis. Herein, we demonstrate a cytoplasmic role for BAF in host defense during poxviral infections. Vaccinia is the prototypic poxvirus, a family of DNA viruses that replicate ex-clusively in the cytoplasm of infected cells. Mutations in the vaccinia B1 kinase (B1) com-promise viral DNA replication, but the mechanism by which B1 achieves this has remained elusive. We now show that BAF acts as a potent inhibitor of poxvirus replication unless its DNA-binding activity is blocked …


Vitamin Status In Yearling Rams With Growth Failure, Handan Mert, Süleyman Kozat, Ni̇hat Mert, Yeter Değer Jan 2007

Vitamin Status In Yearling Rams With Growth Failure, Handan Mert, Süleyman Kozat, Ni̇hat Mert, Yeter Değer

Turkish Journal of Veterinary & Animal Sciences

This study was performed to investigate the serum levels of vitamins in yearling rams with growth failure. A total of 70 yearling rams of Akkaraman breed, 50 of which were classified as growth-failure with an average body weight of 37.30 ± 1.1 kg (test) and the remaining 20 were classified as normal with an average body weight of 67.80 ± 2.2 kg (control), were included in the study. There were significant differences between the yearling rams with and without growth failure in terms of serum levels of vitamin C, \beta-carotene, and vitamins A and E (P < 0.001, P < 0.01, P < 0.001, and P < 0.001, respectively). The levels of all analyzed vitamins were lower compared to controls in yearling rams with growth failure.


Environmental And Genetic Effects On Birth Weight And Survival Rate In Holstein Calves, Serdar Koçak, Mustafa Tekerli̇, Ceyhan Özbeyaz, Banu Yüceer Jan 2007

Environmental And Genetic Effects On Birth Weight And Survival Rate In Holstein Calves, Serdar Koçak, Mustafa Tekerli̇, Ceyhan Özbeyaz, Banu Yüceer

Turkish Journal of Veterinary & Animal Sciences

This study was undertaken to investigate the effects of certain factors on birth weight and survival rate, utilizing the records of 8399 Holstein calves maintained at the Ceylanpınar State Farm in southeastern Anatolia. The data were collected from the calf barn sheets, including birth weight, pedigree details, and calf fate. The survival rate was scored as 1 (alive) or 0 (died) in accordance with the records. Analysis of variance indicated that the effects of year, season, parity, and calf sex on birth weight were significant (P < 0.01). Only calf sex had a significant (P < 0.01) influence on survival rate. The least squares means of birth weight for all calves averaged 38.79 ± 0.171 kg. The survival rates were 0.95 ± 0.004, 0.94 ± 0.004, and 0.92 ± 0.005 at 3, 6, and 12 months of life, respectively. Heritabilities were 0.115 ± 0.0023 for birth weight and 0.020 ± 0.009, 0.011 ± 0.008, and 0.011 ± 0.008 for 3-month, 6-month, and 12-month survival rates. Genetic correlations between birth weight and every rate of survival were estimated as -0.113, -0.012, and 0.106. The corresponding phenotypic correlations were 0.022, 0.014, and -0.013. It was concluded that the birth weight and survival rates of Holstein calves reared at Ceylanpınar State Farm were acceptable. However, further improvements can be accomplished by more effective feeding and management based on the low heritabilities.


The Status Of Childhood Lead Poisoning And Prevention In Nevada, Usa, Anne Rothweiler, Elena E. Cabb, Shawn Gerstenberger Jan 2007

The Status Of Childhood Lead Poisoning And Prevention In Nevada, Usa, Anne Rothweiler, Elena E. Cabb, Shawn Gerstenberger

Environmental & Global Health Faculty Research

One of the first steps in addressing the problem of childhood lead poisoning is to identify the possible sources of exposure in specific communities and target high-risk populations with appropriate interventions. Due to several factors, such as lack of funding and lack of blood lead reporting, little information exists regarding the occurrence of childhood lead poisoning and the prevalence of potential exposure sources in the state of Nevada. Following the recent establishment of a Nevada-based Lead Poisoning Program, we compiled the most current information available on Nevadans, and use this knowledge to suggest future research objectives and outreach activities for …


Aids-Associated Viral Oncogenesis: Overview, Charles Wood Jan 2007

Aids-Associated Viral Oncogenesis: Overview, Charles Wood

Nebraska Center for Virology: Faculty Publications

It has been 25 years since the acquired immunodeficiency syndrome (AIDS) was first described and over 23 years since the human immunodeficiency virus (HIV) associated with the disease was first discovered. In spite of the tremendous progress that was made in understanding both the disease and the virus, there are still millions of people infected, died, or living with the disease. As for the year 2005 alone, the Joint United Nations Programme on HIV/AIDS (http://www.UNAIDS.org) estimates that there are about 40 million people living with HIV/AIDS globally, and approximately 3 million people died from AIDS in the year. Globally, it …


Modulation Of Retroviral Restriction And Proteasome Inhibitor-Resistant Turnover By Changes In The Trim5Α B-Box 2 Domain, Felipe Diaz-Griffero, Alak Kar, Michel Perron, Shi-Hua Xiang, Hassan Javanbakht, Xing Li, Joseph Sodroski Jan 2007

Modulation Of Retroviral Restriction And Proteasome Inhibitor-Resistant Turnover By Changes In The Trim5Α B-Box 2 Domain, Felipe Diaz-Griffero, Alak Kar, Michel Perron, Shi-Hua Xiang, Hassan Javanbakht, Xing Li, Joseph Sodroski

Nebraska Center for Virology: Faculty Publications

An intact B-box 2 domain is essential for the antiretroviral activity of TRIM5α. We modeled the structure of the B-box 2 domain of TRIM5α based on the existing three-dimensional structure of the B-box 2 domain of human TRIM29. Using this model, we altered the residues predicted to be exposed on the surface of this globular structure. Most of the alanine substitutions in these residues exerted little effect on the antiretroviral activity of human TRIM5αhu or rhesus monkey TRIM5αrh. However, alteration of arginine 119 of TRIM5αhu or the corresponding arginine 121 of TRIM5αrh diminished the abilities of …


Autoregulation Of Gld-2 Cytoplasmic Poly(A) Polymerase, Labib Rouhana, Marvin Wickens Jan 2007

Autoregulation Of Gld-2 Cytoplasmic Poly(A) Polymerase, Labib Rouhana, Marvin Wickens

Biological Sciences Faculty Publications

Cytoplasmic polyadenylation regulates mRNA stability and translation and is required for early development and synaptic plasticity. The GLD-2 poly(A) polymerase catalyzes cytoplasmic polyadenylation in the germline of metazoa. Among vertebrates, the enzyme is encoded by two isoforms of mRNA that differ only in the length of their 3′-UTRs. Here we focus on regulation of vertebrateGLD-2 mRNA. We show that the 3′-UTR of GLD-2 mRNA elicits its own polyadenylation and translational activation during frog oocyte maturation. We identify the sequence elements responsible for repression and activation, and demonstrate that CPEB and PUF proteins likely mediate repression in the resting oocyte. …


Structure And Function Of A Chlorella Virus Encoded Glycosyltransferase, Ying Zhang, Ye Xiang, James L. Van Etten, Michael G. Rossmann Jan 2007

Structure And Function Of A Chlorella Virus Encoded Glycosyltransferase, Ying Zhang, Ye Xiang, James L. Van Etten, Michael G. Rossmann

James Van Etten Publications

Paramecium bursaria chlorella virus-1 encodes at least 5 putative glycosyltransferases that are probably involved in the synthesis of the glycan components of the viral major capsid protein. The 1.6 Å crystal structure of one of these glycosyltransferases (A64R) has a mixed α/β fold containing a central, six-stranded β-sheet flanked by α-helices. Crystal structures of A64R, complexed with UDP, CMP, or GDP, established that only UDP bound to A64R in the presence of Mn2+, consistent with its high structural similarity to glycosyltransferases which utilize UDP as the sugar carrier. The structure of the complex of A64R, UDP-glucose, and Mn2+ showed that …


Sequence And Annotation Of The 288-Kb Atcv-1 Virus That Infects An Endosymbiotic Chlorella Strain Of The Heliozoon Acanthocystis Turfacea, Lisa A. Fitzgerald, Michael V. Graves, Xiao Li, James Hartigan, Artur J.P. Pfitzner, Ella Hoffart, James L. Van Etten Jan 2007

Sequence And Annotation Of The 288-Kb Atcv-1 Virus That Infects An Endosymbiotic Chlorella Strain Of The Heliozoon Acanthocystis Turfacea, Lisa A. Fitzgerald, Michael V. Graves, Xiao Li, James Hartigan, Artur J.P. Pfitzner, Ella Hoffart, James L. Van Etten

James Van Etten Publications

Acanthocystis turfacea chlorella virus (ATCV-1), a prospective member of the family Phycodnaviridae, genus Chlorovirus, infects a unicellular, eukaryotic, chlorella-like green alga, Chlorella SAG 3.83, that is a symbiont in the heliozoon A. turfacea. The 288,047-bp ATCV-1 genome is the first virus to be sequenced that infects Chlorella SAG 3.83. ATCV-1 contains 329 putative protein-encoding and 11 tRNA-encoding genes. The protein-encoding genes are almost evenly distributed on both strands and intergenic space is minimal. Thirty-four percent of the viral gene products resemble entries in the public databases, including some that are unexpected for a virus. For example, these …


Chlorella Viruses Contain Genes Encoding A Complete Polyamine Biosynthetic Pathway, Sascha Baumann, Adrienne Sander, James Gurnon, Giane M. Yanai-Balser, James L. Van Etten, Markus Piotrowski Jan 2007

Chlorella Viruses Contain Genes Encoding A Complete Polyamine Biosynthetic Pathway, Sascha Baumann, Adrienne Sander, James Gurnon, Giane M. Yanai-Balser, James L. Van Etten, Markus Piotrowski

James Van Etten Publications

Two genes encoding the putative polyamine biosynthetic enzymes agmatine iminohydrolase (AIH) and N-carbamoylputrescine amidohydrolase (CPA) were cloned from the chloroviruses PBCV-1, NY-2A and MT325. They were expressed in Escherichia coli to form C-terminal (His)6-tagged proteins and the recombinant proteins were purified by Ni2+- binding affinity chromatography. The biochemical properties of the two enzymes are similar to AIH and CPA enzymes from Arabidopsis thaliana and Pseudomonas aeruginosa. Together with the previously known virus genes encoding ornithine/arginine decarboxlyase (ODC/ADC) and homospermidine synthase, the chloroviruses have genes that encode a complete set of functional enzymes that synthesize the rare polyamine homospermidine from arginine …


The Prevalence Of Eimeria Species In Goats In Iğdır, Abdurrahman Gül Jan 2007

The Prevalence Of Eimeria Species In Goats In Iğdır, Abdurrahman Gül

Turkish Journal of Veterinary & Animal Sciences

This study was conducted to identify Eimeria species in goats in 5 districts of Iğdır province in Turkey. Faecal specimens (approximately 3-5 g) were obtained from the rectums of 212 goats. In the laboratory examination of faecal samples, 10 different Eimeria species were identified in 82.55% of the specimens: E. arloingi (47.43%), E. christenseni (45.14%), E. ninakohlyakimovae (36.00%), E. alijevi (26.85%), E. hirci (23.42%), E. caprina (18.28%), E. caprovina (16.57%), E. pallida (13.14%), E. jolchijevi (10.28%), and E. apsheronica (3.42%). E. caprina and E. caprovina are reported for the first time in the Iğdır province of Turkey.


Synthesis And Antifungal Properties Of Alpha-Methoxy And Alpha-Hydroxyl Substituted 4-Thiatetradecanoic Acids, Nestor Carballeira, Rosann O'Neill, Keykavous Parang Jan 2007

Synthesis And Antifungal Properties Of Alpha-Methoxy And Alpha-Hydroxyl Substituted 4-Thiatetradecanoic Acids, Nestor Carballeira, Rosann O'Neill, Keykavous Parang

Pharmacy Faculty Articles and Research

4-Thiatetradecanoic acid exhibited weak antifungal activities against Candida albicans (ATCC 60193), Cryptococcus neoformans (ATCC 6603 1), and Aspergillus niger (ATCC 16404) (MIC = 4.8-12.7 mM). It has been demonstrated that alpha-methoxylation efficiently blocks P-oxidation and significantly improve the antifungal activities of fatty acids. We examined whether antifungal activity of 4-thiatetradecanoic acid can be improved by a-substitution. The unprecedented (+/-)-2-tiydroxy-4-thiatetradecanoic acid was synthesized in four steps (20% overall yield), while the (+/-)-2-methoxy-4-thiatetradecanoic acid was synthesized in five steps (14% overall yield) starting from 1-decanethiol. The key step in the synthesis was the hydrolysis of a trimethylsilyloxynitrile. In general, the novel (+/-)-2-methoxy-4-thiatetradecanoic …


Coupling Coherence Distinguishes Structure Sensitivity In Protein Electron Transfer, Tatiana Prytkova, Igor V. Kurnikov, David Beratan Jan 2007

Coupling Coherence Distinguishes Structure Sensitivity In Protein Electron Transfer, Tatiana Prytkova, Igor V. Kurnikov, David Beratan

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Quantum mechanical analysis of electron tunneling in nine thermally fluctuating cytochrome b562 derivatives reveals two distinct protein-mediated coupling limits. A structure-insensitive regime arises for redox partners coupled through dynamically averaged multiple-coupling pathways (in seven of the nine derivatives) where heme-edge coupling leads to the multiple-pathway regime. A structure-dependent limit governs redox partners coupled through a dominant pathway (in two of the nine derivatives) where axial-ligand coupling generates the single-pathway limit and slower rates. This two-regime paradigm provides a unified description of electron transfer rates in 26 ruthenium-modified heme and blue-copper proteins, as well as in numerous photosynthetic proteins.