Purification and characterization of a vitelline coat lysin from Ciona intestinalis spermatozoa

✍ Scribed by Rita Marino; Rosaria De Santis; Noritaka Hirohashi; Motonori Hoshi; Maria Rosaria Pinto; Noriko Usui

• Book ID: 102951609
• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 610 KB
• Volume: 32
• Category: Article
• ISSN: 1040-452X
• DOI: 10.1002/mrd.1080320412

✦ Synopsis

Abstract

In Ciona intestinalis a chymotrypsin‐like activity is involved in sperm penetration of the egg vitelline coat. A chymotrypsin‐like enzyme has been purified from spermatozoa by a protocol including ion exchange chromatography, gel filtration, and native polyacrylamide gel electrophoresis. The purified enzyme resulted homogeneous when analyzed by SDS‐PAGE. The molecular weight of the chmotrypsin‐like enzyme was estimated to be 35 KDa by gel filtration and 24 KDa by SDS‐PAGE in nonreducing conditions. The pH optimum of the enzyme is 8.4 and its activity is enhanced by Ca^2+^. It shows the highest activity towards the synthetic substrate Suc‐Ala‐Ala‐Pro‐Phe‐AMC. Furthermore, by electron microscopy, the purified enzyme affects the structure of egg vitelline coat, and thus it fulfills one of the criteria of a lysin.