Wayne D. Harshbarger
- Courses2
- Reviews3
- School: Blinn College
- Campus:
- Department: Chemistry
- Email address: Join to see
- Phone: Join to see
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Location:
902 College Ave
Bryan, TX - 77833 - Dates at Blinn College: April 2014 - June 2014
- Office Hours: Join to see
Biography
Blinn College - Chemistry
Experience
GSK
Scientist- Vaccine Design and Characterization GSK Vaccines
Wayne worked at GSK as a Scientist- Vaccine Design and Characterization GSK Vaccines
GSK
Expert Scientist-Structural Biology and Biophysics, Vaccine Design and Characterization GSK Vaccines
Wayne worked at GSK as a Expert Scientist-Structural Biology and Biophysics, Vaccine Design and Characterization GSK Vaccines
Dana-Farber Cancer Institute
Senior Research Fellow
One project works to identify novel broadly neutralizing antibodies targeting Zika, West Nile, Dengue, and Yellow Fever viruses. A second focus is on broadly neutralizing antibodies against influenza A and B, which target novel stem epitopes of hemaggluttinin. In either case, structural biology is the major tool used to characterize the antibody/antigen interactions and facilitate the design of immunogens for vaccination.
Harvard Medical School
Senior Research Fellow
One project works to identify novel broadly neutralizing antibodies targeting Zika, West Nile, Dengue, and Yellow Fever viruses. A second focus is on broadly neutralizing antibodies against influenza A and B, which target novel stem epitopes of hemaggluttinin. In either case, structural biology is the major tool used to characterize the antibody/antigen interactions and facilitate the design of immunogens for vaccination.
Texas A&M University, Laboratory of James Sacchettini
Graduate Research Assistant
Purification,crystallization, and structure determination of Human 20S Proteasome.
Identification of novel inhibitors of the Proteasome via high through put screening.
Mechanism of inhibition determined by co-crystallization.UT Southwestern Medical Center
Post-Doctoral Researcher
Worked at the intersections of biochemistry, structural biology, chemical biology, and chemistry to understand and manipulate the molecular basis of cancer. A major effort is devoted to structure-based design of compounds that perturb cancer biology and therefore have potential to become cancer therapies.
Education
Texas A&M University
Master's degree
Chemistry
Thesis titled " CRYSTAL STRUCTURES OF BINARY AND TERNARY COMPLEXES OF THYMIDYLATE SYNTHASE (THYA) FROM MYCOBACTERIUM TUBERCULOSIS: INSIGHTS INTO SELECTIVITY AND INHIBITION."Texas A&M University
Doctor of Philosophy (Ph.D.)
Chemistry (Structural Biology)
Thesis: "Crystal Structure of the Human 20S Proteasome in Complex with Carfilzomib at 2.6 Angstrom Resolution"Virginia Commonwealth University
Bachelor of Science (B.S.)
Chemistry
Concentration in Biochemistry and Math
Publications
Crystal Structure of the Human 20S Proteasome in Complex with Carfilzomib
Structure (Cell Press)
Proteasome inhibition is highly effective as a treatment for multiple myeloma, and recently carfilzomib was granted US FDA approval for the treatment of relapsed and refractory multiple myeloma. Here, we report the X-ray crystal structure of the human constitutive 20S proteasome with and without carfilzomib bound at 2.9 and 2.6 Å, respectively. Our data indicate that the S3 and S4 binding pockets play a pivotal role in carfilzomib’s selectivity for chymotrypsin-like sites. Structural comparison with the mouse immunoproteasome crystal structure reveals amino acid substitutions that explain carfilzomib’s slight preference for chymotrypsin-like subunits of constitutive proteasomes. In addition, comparison of the human proteasome:carfilzomib complex with the mouse proteasome:PR-957 complex reveals new details that explain why PR-957 is selective for immunoproteasomes. Together, the data presented here support the design of inhibitors for either constitutive or immunoproteasomes, with implications for the treatment of cancers as well as autoimmune and neurodegenerative diseases.
Crystal Structure of the Human 20S Proteasome in Complex with Carfilzomib
Structure (Cell Press)
Proteasome inhibition is highly effective as a treatment for multiple myeloma, and recently carfilzomib was granted US FDA approval for the treatment of relapsed and refractory multiple myeloma. Here, we report the X-ray crystal structure of the human constitutive 20S proteasome with and without carfilzomib bound at 2.9 and 2.6 Å, respectively. Our data indicate that the S3 and S4 binding pockets play a pivotal role in carfilzomib’s selectivity for chymotrypsin-like sites. Structural comparison with the mouse immunoproteasome crystal structure reveals amino acid substitutions that explain carfilzomib’s slight preference for chymotrypsin-like subunits of constitutive proteasomes. In addition, comparison of the human proteasome:carfilzomib complex with the mouse proteasome:PR-957 complex reveals new details that explain why PR-957 is selective for immunoproteasomes. Together, the data presented here support the design of inhibitors for either constitutive or immunoproteasomes, with implications for the treatment of cancers as well as autoimmune and neurodegenerative diseases.
Structural and Biochemical Analyses Reveal the Mechanism of Glutathione S-Transferase Pi 1 Inhibition by the Anti-cancer Compound Piperlongumine
The Journal of Biological Chemistry
Glutathione S-transferase pi 1 (GSTP1) is frequently overexpressed in cancerous tumors and is a putative target of the plant compound piperlongumine (PL), which contains two reactive olefins and inhibits proliferation in cancer cells but not normal cells. PL exposure of cancer cells results in increased reactive oxygen species and decreased GSH. These data in tandem with other information led to the conclusion that PL inhibits GSTP1, which forms covalent bonds between GSH and various electrophilic compounds, through covalent adduct formation at the C7-C8 olefin of PL, whereas the C2-C3 olefin of PL was postulated to react with GSH. However, direct evidence for this mechanism has been lacking. To investigate, we solved the X-ray crystal structure of GSTP1 bound to PL and GSH at 1.1 Å resolution to rationalize previously reported structure activity relationship studies. Surprisingly, the structure showed that a hydrolysis product of PL (hPL) was conjugated to glutathione at the C7-C8 olefin, and this complex was bound to the active site of GSTP1; no covalent bond formation between hPL and GSTP1 was observed. Mass spectrometry (MS) analysis of the reactions between PL and GSTP1 confirmed that PL does not label GSTP1. Moreover, MS data also indicated that nucleophilic attack on PL at the C2-C3 olefin led to PL hydrolysis. Although hPL inhibits GSTP1 enzymatic activity in vitro, treatment of cells susceptible to PL with hPL did not have significant anti-proliferative effects, suggesting that hPL is not membrane-permeable. Altogether, our data suggest a model wherein PL is a prodrug whose intracellular hydrolysis initiates the formation of the hPL-GSH conjugate, which blocks the active site of and inhibits GSTP1 and thereby cancer cell proliferation.
Crystal Structure of the Human 20S Proteasome in Complex with Carfilzomib
Structure (Cell Press)
Proteasome inhibition is highly effective as a treatment for multiple myeloma, and recently carfilzomib was granted US FDA approval for the treatment of relapsed and refractory multiple myeloma. Here, we report the X-ray crystal structure of the human constitutive 20S proteasome with and without carfilzomib bound at 2.9 and 2.6 Å, respectively. Our data indicate that the S3 and S4 binding pockets play a pivotal role in carfilzomib’s selectivity for chymotrypsin-like sites. Structural comparison with the mouse immunoproteasome crystal structure reveals amino acid substitutions that explain carfilzomib’s slight preference for chymotrypsin-like subunits of constitutive proteasomes. In addition, comparison of the human proteasome:carfilzomib complex with the mouse proteasome:PR-957 complex reveals new details that explain why PR-957 is selective for immunoproteasomes. Together, the data presented here support the design of inhibitors for either constitutive or immunoproteasomes, with implications for the treatment of cancers as well as autoimmune and neurodegenerative diseases.
Structural and Biochemical Analyses Reveal the Mechanism of Glutathione S-Transferase Pi 1 Inhibition by the Anti-cancer Compound Piperlongumine
The Journal of Biological Chemistry
Glutathione S-transferase pi 1 (GSTP1) is frequently overexpressed in cancerous tumors and is a putative target of the plant compound piperlongumine (PL), which contains two reactive olefins and inhibits proliferation in cancer cells but not normal cells. PL exposure of cancer cells results in increased reactive oxygen species and decreased GSH. These data in tandem with other information led to the conclusion that PL inhibits GSTP1, which forms covalent bonds between GSH and various electrophilic compounds, through covalent adduct formation at the C7-C8 olefin of PL, whereas the C2-C3 olefin of PL was postulated to react with GSH. However, direct evidence for this mechanism has been lacking. To investigate, we solved the X-ray crystal structure of GSTP1 bound to PL and GSH at 1.1 Å resolution to rationalize previously reported structure activity relationship studies. Surprisingly, the structure showed that a hydrolysis product of PL (hPL) was conjugated to glutathione at the C7-C8 olefin, and this complex was bound to the active site of GSTP1; no covalent bond formation between hPL and GSTP1 was observed. Mass spectrometry (MS) analysis of the reactions between PL and GSTP1 confirmed that PL does not label GSTP1. Moreover, MS data also indicated that nucleophilic attack on PL at the C2-C3 olefin led to PL hydrolysis. Although hPL inhibits GSTP1 enzymatic activity in vitro, treatment of cells susceptible to PL with hPL did not have significant anti-proliferative effects, suggesting that hPL is not membrane-permeable. Altogether, our data suggest a model wherein PL is a prodrug whose intracellular hydrolysis initiates the formation of the hPL-GSH conjugate, which blocks the active site of and inhibits GSTP1 and thereby cancer cell proliferation.
A Strategy for Dual Inhibition of the Proteasome and Fatty Acid Synthase with Belactosin C-Orlistat Hybrids
Bioorganic & Medicinal Chemistry
The proteasome, a validated cellular target for cancer, is central for maintaining cellular homeostasis, while fatty acid synthase (FAS), a novel target for numerous cancers, is responsible for palmitic acid biosynthesis. Perturbation of either enzymatic machine results in decreased proliferation and ultimately cellular apoptosis. Based on structural similarities, we hypothesized that hybrid molecules of belactosin C, a known proteasome inhibitor, and orlistat, a known inhibitor of the thioesterase domain of FAS, could inhibit both enzymes. Herein, we describe proof-of-principle studies leading to the design, synthesis and enzymatic activity of several novel, β-lactone-based, dual inhibitors of these two enzymes. Validation of dual enzyme targeting through activity-based proteome profiling with an alkyne probe modeled after the most potent inhibitor, and preliminary serum stability studies of selected derivatives are also described. These results provide proof of concept for dual targeting of the proteasome and FAS-TE enabling a new approach for the development of drug-candidates with potential to overcome resistance.
Positions
Graduate Student Association of Chemistry
Secretary
Interacted with the Graduate Student Office and the Graduate Student Council to improve the graduate studies experience at Texas A&M University.
Graduate Student Association of Chemistry
Secretary
Interacted with the Graduate Student Office and the Graduate Student Council to improve the graduate studies experience at Texas A&M University.
Graduate Student Council
Legislative Affairs Committee
Addressed issues at the state and federal level that affect Texas A&M students.
Graduate Student Association of Chemistry
Secretary
Interacted with the Graduate Student Office and the Graduate Student Council to improve the graduate studies experience at Texas A&M University.
Graduate Student Council
Legislative Affairs Committee
Addressed issues at the state and federal level that affect Texas A&M students.
Graduate Student Association of Chemistry
Secretary
Interacted with the Graduate Student Office and the Graduate Student Council to improve the graduate studies experience at Texas A&M University.
Graduate Student Council
Legislative Affairs Committee
Addressed issues at the state and federal level that affect Texas A&M students.
Graduate Student Association of Chemistry
Secretary
Interacted with the Graduate Student Office and the Graduate Student Council to improve the graduate studies experience at Texas A&M University.
Graduate Student Council
Legislative Affairs Committee
Addressed issues at the state and federal level that affect Texas A&M students.
Graduate Student Association of Chemistry
Secretary
Interacted with the Graduate Student Office and the Graduate Student Council to improve the graduate studies experience at Texas A&M University.
Graduate Student Council
Legislative Affairs Committee
Addressed issues at the state and federal level that affect Texas A&M students.
Graduate Student Association of Chemistry
Secretary
Interacted with the Graduate Student Office and the Graduate Student Council to improve the graduate studies experience at Texas A&M University.
Graduate Student Council
Legislative Affairs Committee
Addressed issues at the state and federal level that affect Texas A&M students.
Graduate Student Association of Chemistry
Secretary
Interacted with the Graduate Student Office and the Graduate Student Council to improve the graduate studies experience at Texas A&M University.
Graduate Student Council
Legislative Affairs Committee
Addressed issues at the state and federal level that affect Texas A&M students.
Graduate Student Association of Chemistry
Secretary
Interacted with the Graduate Student Office and the Graduate Student Council to improve the graduate studies experience at Texas A&M University.
Graduate Student Council
Legislative Affairs Committee
Addressed issues at the state and federal level that affect Texas A&M students.
Graduate Student Association of Chemistry
Secretary
Interacted with the Graduate Student Office and the Graduate Student Council to improve the graduate studies experience at Texas A&M University.
Graduate Student Council
Legislative Affairs Committee
Addressed issues at the state and federal level that affect Texas A&M students.
