Experts and Doctors on amino acid isomerases in Boston, Massachusetts, United States


Locale: Boston, Massachusetts, United States
Topic: amino acid isomerases

Top Publications

  1. Rusnak F, Sakaitani M, Drueckhammer D, Reichert J, Walsh C. Biosynthesis of the Escherichia coli siderophore enterobactin: sequence of the entF gene, expression and purification of EntF, and analysis of covalent phosphopantetheine. Biochemistry. 1991;30:2916-27 pubmed
    ..In a search for possible causes for the low level of activity of the overexpressed enzyme, we have discovered that EntF contains a covalently bound phosphopantetheine cofactor. ..
  2. Fejzo J, Etzkorn F, Clubb R, Shi Y, Walsh C, Wagner G. The mutant Escherichia coli F112W cyclophilin binds cyclosporin A in nearly identical conformation as human cyclophilin. Biochemistry. 1994;33:5711-20 pubmed
    ..coli protein is substantially different at the site most distant to tryptophan 121 (human sequence). This site is constructed by a five-residue insertion in a loop of the E. coli protein, replacing another loop in the human protein. ..
  3. Nadeau K, Das A, Walsh C. Hsp90 chaperonins possess ATPase activity and bind heat shock transcription factors and peptidyl prolyl isomerases. J Biol Chem. 1993;268:1479-87 pubmed
    ..We also detect binding of the other family of PPIases, the cyclophilins, to immobilized hsp90, consistent with a functional convergence of protein foldases. ..
  4. Pogliano J, Lynch A, Belin D, Lin E, Beckwith J. Regulation of Escherichia coli cell envelope proteins involved in protein folding and degradation by the Cpx two-component system. Genes Dev. 1997;11:1169-82 pubmed
    ..coli genes. These findings suggest a potentially extensive Cpx regulon including genes transcribed by sigma70 and sigma(E), which encode factors involved in protein folding as well as other cellular functions. ..
  5. Dorfman T, Weimann A, Borsetti A, Walsh C, Gottlinger H. Active-site residues of cyclophilin A are crucial for its incorporation into human immunodeficiency virus type 1 virions. J Virol. 1997;71:7110-3 pubmed
    ..The remaining six CyPA mutants were incorporated with markedly reduced efficiency, providing in vivo evidence that HIV-1 CA interacts with the active site of CyPA. ..
  6. Jin Y, Burakoff S, Bierer B. Molecular cloning of a 25-kDa high affinity rapamycin binding protein, FKBP25. J Biol Chem. 1992;267:10942-5 pubmed
    ..These data demonstrate that FKBP25 has a higher affinity for rapamycin than for FK506 and suggest that this cellular receptor may be an important target molecule for immunosuppression by rapamycin. ..
  7. Walsh C, Zydowsky L, McKeon F. Cyclosporin A, the cyclophilin class of peptidylprolyl isomerases, and blockade of T cell signal transduction. J Biol Chem. 1992;267:13115-8 pubmed
    ..The molecular insights gained over a short time in this area have been remarkable; they promise to elucidate the steps in T cell activation and delineate new targets for immunosuppressive therapy. ..
  8. Liu J, Chen C, Walsh C. Human and Escherichia coli cyclophilins: sensitivity to inhibition by the immunosuppressant cyclosporin A correlates with a specific tryptophan residue. Biochemistry. 1991;30:2306-10 pubmed
  9. Thali M, Bukovsky A, Kondo E, Rosenwirth B, Walsh C, Sodroski J, et al. Functional association of cyclophilin A with HIV-1 virions. Nature. 1994;372:363-5 pubmed
    ..Moreover, SDZ NIM811 inhibited the replication of HIV-1 but was inactive against SIVMAC, a primate immunodeficiency virus closely related to HIV-1, which does not incorporate cyclophilin A. ..

More Information


  1. Clubb R, Ferguson S, Walsh C, Wagner G. Three-dimensional solution structure of Escherichia coli periplasmic cyclophilin. Biochemistry. 1994;33:2761-72 pubmed
    ..A residue essential for isomerase activity in human T cell cyclophilin (His126) is replaced by Tyr122 in E. coli cyclophilin without affecting enzymatic activity. ..
  2. Luo L, Walsh C. Kinetic analysis of three activated phenylalanyl intermediates generated by the initiation module PheATE of gramicidin S synthetase. Biochemistry. 2001;40:5329-37 pubmed
    ..This study provides the first transient-state kinetic analysis of a nonribosomal peptide synthetase (NRPS) module. ..