Active site of tripeptidyl peptidase II from human erythrocytes is of the subtilisin type

Journal Article · Sun Nov 01 00:00:00 EST 1987 · Proc. Natl. Acad. Sci. U.S.A.; (United States)

DOI:https://doi.org/10.1073/pnas.84.21.7508· OSTI ID:7075547

Tomkinson, B; Wernstedt, C; Hellman, U; Zetterqvist, Oe

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 (/sup 3/H)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.

• Research Organization: Univ. of Uppsala (Sweden)
• OSTI ID: 7075547
• Journal Information: Proc. Natl. Acad. Sci. U.S.A.; (United States), Vol. 84:21
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
SERINE PROTEINASES
AMINO ACID SEQUENCE
BIOLOGICAL EVOLUTION
RADIOCHROMATOGRAPHY
ERYTHROCYTES
LIQUID COLUMN CHROMATOGRAPHY
MAN
TRITIUM COMPOUNDS
ANIMALS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CHROMATOGRAPHY
ENZYMES
HYDROLASES
LABELLED COMPOUNDS
MAMMALS
MATERIALS
MOLECULAR STRUCTURE
PEPTIDE HYDROLASES
PRIMATES
SEPARATION PROCESSES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques