Isolation and amino-acid sequence of two inhibitors of serine proteinases, members of the squash inhibitor family, from Echinocystis lobata seeds
Two serine proteinase inhibitors (ELTI I and ELTI II) have been isolated from mature seeds of Echinocystis lobata by ammonium sulfate fractionation, methanol precipitation, ion exchange chromatography, affinity chromatography on immobilized anhydrotrypsin and HPLC. ELTI I and ELTI II consist of 33 a...
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Published in | Acta biochimica polonica Vol. 43; no. 3; pp. 507 - 513 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Poland
01.01.1996
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Subjects | |
Online Access | Get full text |
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Summary: | Two serine proteinase inhibitors (ELTI I and ELTI II) have been isolated from mature seeds of Echinocystis lobata by ammonium sulfate fractionation, methanol precipitation, ion exchange chromatography, affinity chromatography on immobilized anhydrotrypsin and HPLC. ELTI I and ELTI II consist of 33 and 29 amino-acid residues, respectively. The primary structures of these inhibitors are as follows: ELTI I KEEQRVCPRILMRCKRDSDCLAQCTCQQSGFCG ELTI II RVCPRILMRCKRDSDCLAQCTCQQSGFCG The inhibitors show sequence similarity with the squash inhibitor family. ELTI I differs from ELTI II only by the presence of the NH2-terminal tetrapeptide Lys-Glu-Glu-Gln. The association constants (Ka) of ELTI I and ELTI II with bovine-trypsin were determined to be 6.6 x 10(10) M-1, and 3.1 x 10(11) M-1, whereas the association constants of these inhibitors with cathepsin G were 1.2 x 10(7) M-1, and 1.1 x 10(7) M-1, respectively. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0001-527X 1734-154X |
DOI: | 10.18388/abp.1996_4484 |