Active site of tripeptidyl peptidase II from human erythrocytes is of the subtilisin type.
AUTOR(ES)
Tomkinson, B
RESUMO
The present report presents evidence that the amino acid sequence around the serine of the active site of human tripeptidyl peptidase II is of the subtilisin type. The enzyme from human erythrocytes was covalently labeled at its active site with [3H]diisopropyl fluorophosphate, and the protein was subsequently reduced, alkylated, and digested with trypsin. The labeled tryptic peptides were purified by gel filtration and repeated reversed-phase HPLC, and their amino-terminal sequences were determined. Residue 9 contained the radioactive label and was, therefore, considered to be the active serine residue. The primary structure of the part of the active site (residues 1-10) containing this residue was concluded to be Xaa-Thr-Gln-Leu-Met-Asx-Gly-Thr-Ser-Met. This amino acid sequence is homologous to the sequence surrounding the active serine of the microbial peptidases subtilisin and thermitase. These data demonstrate that human tripeptidyl peptidase II represents a potentially distinct class of human peptidases and raise the question of an evolutionary relationship between the active site of a mammalian peptidase and that of the subtilisin family of serine peptidases.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=299325Documentos Relacionados
- Tripeptidyl Peptidase II. An Oligomeric Protease Complex from Arabidopsis1
- Molecular architecture and assembly mechanism of Drosophila tripeptidyl peptidase II
- Identification of histidine 64 in the active site of subtilisin.
- Tripeptidyl Peptidase II Promotes Maturation of Caspase-1 in Shigella flexneri-Induced Macrophage Apoptosis
- PROPERTIES OF A BLOCKED TETRAPEPTIDE ANALOGUE OF THE ACTIVE SITE OF SUBTILISIN*