Primary structure of potato kunitz-type serine proteinase inhibitor.
Biol Chem
; 381(12): 1215-21, 2000 Dec.
Article
en En
| MEDLINE
| ID: mdl-11209756
ABSTRACT
The serine proteinase inhibitor (PSPI-21) isolated from potato tubers (Solanum tuberosum L.) comprises two protein species with pI 5.2 and 6.3, denoted as PSPI-21-5.2 and PSPI-21-6.3, respectively. They were separated by anion exchange chromatography on a Mono Q FPLC column. Both species tightly inhibit human leukocyte elastase, whereas their interaction with trypsin and chymotrypsin is substantially weaker. The sequences of both PSPI-21-5.2 and PSPI-21-6.3 were determined by analysis of overlapping peptides obtained from the oxidized or reduced and S-pyridylethylated proteins after digestion with trypsin or pepsin. Both species of PSPI-21 are composed of two chains, named chains A and B, which are linked by a disulfide bridge between Cys(146) and Cys(157). The other disulfide bridge is located within the A chains between Cys(48) and Cys(97). The amino acid sequences of the large A chains of the two forms, consisting of 150 amino acids residues each, differ in a single residue at position 52. The small chains B, containing 37 and 36 residues in PSPI-21-6.3 and PSPI-21-5.2, respectively, have nine different residues. The entire amino acid sequences of the two inhibitors show a high degree of homology to the other Kunitz-type proteinase inhibitors from plants.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Péptidos
/
Proteínas de Plantas
/
Solanum tuberosum
/
Inhibidores de Tripsina
Límite:
Humans
Idioma:
En
Revista:
Biol Chem
Asunto de la revista:
BIOQUIMICA
Año:
2000
Tipo del documento:
Article