Isolation, purification and characterization of a DPP-III homologue from goat brain.
A dipeptidyl peptidase (DPP) from goat brain has been purified. The purified enzyme showed a single band on sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). It is a monomer with molecular weight of 69kDa with a pI of 4.5. The K(m) was estimated to be 39microM for Arg-Arg-4-methoxy-beta-naphthylamide (Arg-Arg-4mbetaNA). This enzyme is strongly inhibited by commonly used metallochelators and sulfhydryl reagents. Among various beta-naphthylamides examined, Arg-Arg-4mbetaNA was the most rapidly hydrolyzed substrate. Although, initially it was thought to be the DPP-III but on the basis of its molecular weight and inhibition studies, it was concluded that this enzyme is a functional homologue of DPP-III.
Dhanda
Suman
S
Department of Biochemistry, Kurukshetra University, Kurukshetra 136119, Haryana, India. dhandasuman@rediffmail.com
Singh
Hari
H
Singh
Jasbir
J
Singh
Tej P
TP
D000818:Animals; D000829:Animals, Domestic; D001921:Brain / Q000201:enzymology*; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D004795:Enzyme Stability; D006041:Goats; D007700:Kinetics; D013379:Substrate Specificity
D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; C100152:dipeptidyl peptidase III