Author/Editor		Meško-Brguljan, Pika; Turk, Vito; Cimerman, Nina; Brzin, Jože; Križaj, Igor; Popovič, Tatjana
Title		Human brain cathepsin H as a neuropeptide and bradykinin metabolizing enzyme
Type		članek
Source		Peptides
Vol. and No.		Letnik 24
Publication year		2003
Volume		str. 1977-84
Language		eng
Abstract		Highly purified human brain cathepsin H (EC 3.4.22.16) was used to study its involvement in degradation of different brain peptides. Its action was determined to be selective. On Leu-enkephalin, dynorphin (1-6), dynorphin (1-13), alpha-neoendorphin, and Lys-bradykinin, it showed a preferential aminopeptidase activity by cleaving off hydrophobic or basic amino acids. It showed no aminopeptidase activity on bradykinin, which has Pro adjacent to its N-terminal amino acid, on neurotensin with blocked N-terminal amino acid, or on dennorphin with second amino acid D-alanine. After prolonged incubation, cathepsin H acted as an endopeptidase. Dermorphin and dynorphin (1-13) were cleaved at bonds with Phe in the P2 position, while dynorphin ( l-6), a-neoendorphin, bradykinin and Lys-bradykinin were cleaved at bouds with Gly in the P2 position. Further on, it was shown that human brain cathepsin H activity could be controlled in vivo by eystatin C in its full-length form or its [delta 1-10] variant, already known to be co-localized in astrocytes, since the Ki values for the inhibition are in the 10-10 M range.
Descriptors		BRAIN CATHEPSINS CYSTATINS NEUROPEPTIDES BRADYKININ ELECTROPHORESIS, POLYACRYLAMIDE GEL ENZYME-LINKED IMMUNOSORBENT ASSAY ISOELECTRIC FOCUSING AUTOPSY