Effects of Protease from Plerocercoid of Spirometra erinacei on Host Structural Protein.

1989 Fiscal Year Final Research Report Summary

• Project/Area Number: 63570182
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: 寄生虫学(含医用動物学）
• Research Institution: Kitasato University
• Principal Investigator: YANAGISAWA Toshio Kitasato Univ. Sch. of Med. Prof., 医学部, 教授 (20050312)
• Co-Investigator(Kenkyū-buntansha): NAKAMURA Takeshi Kitasato Univ. Sch. of Med. Assistant Prof., 医学部, 講師 (30050652)
• Project Period (FY): 1988 – 1989
• Keywords: Spirometra erinacei / Plerocercoid / Cysteine protease

Research Abstract

Thiol protease was isolated from plerocercoid of Spirometra erinacei (plerocercoid protease, pl-p). Splitting activities of the protease against structural and contractile proteins from host vertebrate skeletal muscle were investigated. the results obtained are as follows.
1) Pl-P may cleave native actin and myosin peptides. G-actin is digested by pl-p more quickly than F-actin. ATPase activity remained intact on the residues produced by myosin digestion.
2) A myofibril prepared from host skeletal muscle, having macromolecular structure may also digested by pl-p in vitro. myosin, a constituent of the thick-filament on, myofibril, is splitted and dissolved without a loss of its ATPase activity.
3) Effects of pl-p on the host actomyosin containing a regulatory system (myosin-B) were examined by changes in superprecipitation as an in vitro model of muscular contraction. Ca^<2+>-sensitivity in the actomyosin system is lost by the addition of pl-p.
4) The effect of pl-p on regulatory proteins, tropomyosin and troponin was examined. Substrates used are cleaved more preferably cleaved by pl-p in the following order: troponin T-subunit<greater than or equal> troponin I-subunit > tropomyosin > troponin C
Results obtained from the present study suggest that pl-p from S. erinacei plerocercoids may be able to degradate host muscular structure.