Biochemical characteristics of myofibrillar proteins of the fish parasite Isoparorchis hypselobagri (Trematoda) as survival traits in an oxygen-rich environment

• Published in: biolet
• Main Authors: Abbasi, Usma, Ahmad, Riaz, Hasnain, Absar-ul
• Format: Article in Journal/Newspaper
• Language: English
• Published: Walter de Gruyter GmbH 2012
• Subjects: General Agricultural and Biological Sciences; General Biochemistry, Genetics and Molecular Biology; Attu
• Online Access: http://dx.doi.org/10.2478/v10120-012-0009-0; http://content.sciendo.com/view/journals/biolet/49/1/article-p45.xml; https://www.sciendo.com/pdf/10.2478/v10120-012-0009-0

Abstract We have investigated biochemical properties of myofibrillar proteins of the digenetic trematode Isoparorchis hypselobagri, which correlate with its survival in the oxygen-rich swim bladder of its host catfish (Wallago attu). The polypeptide composition of the trematode’s natural actomyosin (NAM) was striated-muscle-like, with the exception that a 98-kD polypeptide corresponding to paramyosin also existed in its sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) profiles. The profiles of immunoprecipitated NAM of the trematode support these inferences. Ca2+-sensitivity of myofibrillar contractility and Mg2+-ATPase activity of I. hypselobagri resembled troponin-linked calcium regulation of the host striated muscle. Myofibrillar permeability to water influx was insensitive to calcium chelation at neutral pH. However, the host swim bladder myofibrils displayed smooth-muscle-like polypeptide composition, pH dependence of contractility, Ca2+-sensitivity, ATPase activities, and inactivation kinetics. We propose 2 survival strategies that I. hypselobagri appears to have co-evolved: (i) fast-muscle-like musculature with exceptionally high contractility or ATPase activity; and (ii) type-II myosin resembling the host muscle in functional plasticity.