Substrate specificity of prostate-specific membrane antigen.
A series of putative dipeptide substrates of prostate-specific membrane antigen (PSMA) was prepared that explored alpha- and beta/gamma-linked acidic residues at the P1 position and various chromophores at the P2 position, while keeping the P1' residue constant as L-Glu. Four chromophores were examined, including 4-phenylazobenzoyl, 1-pyrenebutyryl, 9-anthracenylcarboxyl-gamma-aminobutyryl, and 4-nitrophenylbutyryl. When evaluating these chromophores, it was found that a substrate containing 4-phenylazobenzoyl at the P2 position was consumed most efficiently. Substitution at the P1 position with acidic residues showed that only gamma-linked L-Glu and D-Glu were recognized by the enzyme, with the former being more readily proteolyzed. Lastly, binding modes of endogenous substrates and our best synthetic substrate (4-phenylazobenzoyl-Glu-gamma-Glu) were proposed by computational docking studies into an X-ray crystal structure of the PSMA extracellular domain.
Anderson
Marc O
MO
Department of Chemistry & Biochemistry, San Francisco State University, San Francisco, CA 94132, USA.
Wu
Lisa Y
LY
Santiago
Nicholas M
NM
Moser
Jamie M
JM
Rowley
Jennifer A
JA
Bolstad
Erin S D
ES
Berkman
Clifford E
CE
D000954:Antigens, Surface / Q000737:chemistry*; D002856:Chromatophores / Q000737:chemistry; D018360:Crystallography, X-Ray; D004151:Dipeptides / Q000737:chemistry*; D043425:Glutamate Carboxypeptidase II / Q000737:chemistry*; D006801:Humans; D008297:Male; D008958:Models, Molecular; D017434:Protein Structure, Tertiary; D013379:Substrate Specificity
C525226:4-phenylazobenzoyl-Glu-gamma-Glu; D000954:Antigens, Surface; D004151:Dipeptides; C473848:FOLH1 protein, human; D043425:Glutamate Carboxypeptidase II