
Abstract
The serine proteinase inhibitor (PSPI-51) 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.
Item Type: | Journal article |
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Form of publication: | Publisher's Version |
Faculties: | Medicine |
Subjects: | 500 Science > 540 Chemistry |
URN: | urn:nbn:de:bvb:19-epub-17873-8 |
ISSN: | 1431-6730 |
Alliance/National Licence: | This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. |
Language: | English |
Item ID: | 17873 |
Date Deposited: | 02. Jan 2014, 10:33 |
Last Modified: | 04. Nov 2020, 12:59 |