|
|
|
|
Vol. 55, Issue 1, 179-185, January 1999
Laboratory of Molecular and Developmental Neuroscience,
Massachusetts General Hospital-East, Charlestown, Massachusetts
Glutamate carboxypeptidase II (GCP II) catalyzes the extracellular
hydrolysis of the neuromodulator
N-acetyl-aspartylglutamate to
N-acetyl-aspartate and glutamate. GCP II also hydrolyzes
-glutamyl bonds in folylpolyglutamate. The predicted amino acid
sequence of GCP II displays similarities to aminopeptidases from
Streptomyces griseus and Vibrio
proteolyticus, whose crystal structures have been determined.
These aminopeptidases are cocatalytic zinc metallopeptidases belonging
to the peptidase family M28. Specific zinc and substrate ligands have
been proposed in GCP II based on the amino acid sequence alignment to
these M28 family members. In the present study, site-directed mutagenesis has been used to test the assignment of these putative ligands in human GCP II. Substitutions to the five putative zinc ligands resulted in severely reduced enzyme activity, although mutant
protein was expressed as demonstrated by immunoblot analysis. In
addition, substitutions of amino acids near the putative zinc ligands
have identified other specific residues important for enzyme structure
and/or function. Substitutions to putative substrate ligands were less
perturbing, and increases in Km were
observed for substitutions that introduced a large charge perturbation (e.g., Lys to Glu). The results from substitutions at the proposed zinc
and substrate ligands are consistent with the assignment of these
residues and suggest that GCP II has a three-dimensional structure
similar to other members of the peptidase family M28.
This article has been cited by other articles:
![]() |
H. Unno, T. Yamashita, S. Ujita, N. Okumura, H. Otani, A. Okumura, K. Nagai, and M. Kusunoki Structural Basis for Substrate Recognition and Hydrolysis by Mouse Carnosinase CN2 J. Biol. Chem., October 3, 2008; 283(40): 27289 - 27299. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. I. Davis, M. J. Bennett, L. M. Thomas, and P. J. Bjorkman Crystal structure of prostate-specific membrane antigen, a tumor marker and peptidase PNAS, April 26, 2005; 102(17): 5981 - 5986. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Ghosh, X. Wang, E. Klein, and W. D.W. Heston Novel Role of Prostate-Specific Membrane Antigen in Suppressing Prostate Cancer Invasiveness Cancer Res., February 1, 2005; 65(3): 727 - 731. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. A. Rajasekaran, G. Anilkumar, E. Oshima, J. U. Bowie, H. Liu, W. Heston, N. H. Bander, and A. K. Rajasekaran A Novel Cytoplasmic Tail MXXXL Motif Mediates the Internalization of Prostate-specific Membrane Antigen Mol. Biol. Cell, December 1, 2003; 14(12): 4835 - 4845. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Schulke, O. A. Varlamova, G. P. Donovan, D. Ma, J. P Gardner, D. M. Morrissey, R. R. Arrigale, C. Zhan, A. J. Chodera, K. G. Surowitz, et al. The homodimer of prostate-specific membrane antigen is a functional target for cancer therapy PNAS, October 28, 2003; 100(22): 12590 - 12595. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. M. Devlin, E.-h. Ling, J. M. Peerson, S. Fernando, R. Clarke, A. D. Smith, and C. H. Halsted Glutamate carboxypeptidase II: a polymorphism associated with lower levels of serum folate and hyperhomocysteinemia Hum. Mol. Genet., November 1, 2000; 9(19): 2837 - 2844. [Abstract] [Full Text] [PDF] |
||||