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W. Malcolm Byrnes, PhD

Associate Professor

  • Biochemistry
  • College of Medicine



  • Ph.D. in Biochemistry, Louisiana State University, Baton Rouge, 1994
  • Postdoctoral Researcher, Cornell University, Ithaca, NY, 1994-1996


Courses Currently Teaching

  • Dental Biochemistry
  • Enzymology (coordinator)
  • First Year Medical Course: Molecules and Cells Unit IA
  • General Biochemistry
  • General Biochemistry Laboratory
  • Preliminary Academic Reinforcement Program (PARP)
  • Principles of Metabolic Regulation (coordinator)


Research Interests

Recent NIH-funded research in my laboratory has focused on the characterization of anthranilate synthase and related chorismate-utilizing enzymes from bacteria. Anthranilate synthase catalyzes the conversion of chorismate to anthranilate using an amino group derived from glutamine; this reaction represents the first step of the tryptophan biosynthetic pathway. Work in the laboratory has involved the characterization of a fused (TrpE-TrpG) anthranilate synthase from the antibiotic-producing bacterium Streptomyces venezuelae. Our results showed that the enzyme, unlike other anthranilate synthases, functions as a monomer. Moreover, like certain aminodeoxyisochorismate (ADIC) synthases with which it shares high amino acid sequence similarity, the fused enzyme cannot use exogenous ammonia as a substrate. We have also been working on confirming the amino acid residues that line the chorismate site using both site-directed mutagenesis and protein homology modeling. In addition, we have identified, using site-directed mutagenesis, structural features important for tryptophan inhibition of the enzyme. Other research projects I have undertaken in the past have involved, for example, the allosteric enzyme phosphofructokinase, the streptomycin-inactivating enzymes APH(6)-Ia and -Id, and the DNA polymerase from Thermus aquaticus (Taq polymerase). Finally, in addition to my work in biochemistry, I am engaged in scholarly pursuits in other areas: bioethics; ecological ethics, especially as it relates to climate change; the science-religion debate; and the scientific legacy of biologist Ernest Everett Just. More information about my background and work can be found on my ResearchGate site.



For a partial listing, see PubMed. For a full listing, see my CV (above).