Biochemical Susceptibility of Myosin in Chicken Myofibrils Subjected to Hydroxyl Radical Oxidizing Systems

Citations Over TimeTop 10% of 2004 papers

Abstract

Biochemical changes of myosin in chicken myofibrils exposed to nonenzymatic, hydroxyl radical generation systems (HRGS) were investigated by means of cross-linking reaction, ATPase activity, salt solubility, and 40% saturated ammonium sulfate (AS) extractability. HRGS treatment of myofibrils caused cross-linking of myosin heavy chains (MHC) via disulfide bonding, an increase in Ca-ATPase activity, and a decrease in K-ATPase activity, suggesting that thiol groups of myosin including those at the active site were modified. The specific changes depended on the concentrations of H(2)O(2) in HRGS as well as the weight ratio of H(2)O(2) to myofibrils. On the other hand, the decrease in salt solubility or AS extractability of myosin in HRGS-treated samples proceeded slowly when compared with the cross-linking reaction of MHC, indicating that considerable amounts of myosin biopolymers remained hydrophilic in the ionic solutions. The results demonstrated that initial cross-linking of MHC occurred inside the myosin molecule, and this was followed by progressive aggregation of myosin molecules through intermolecular cross-linking. Oxidation under the current experimental condition decreased the gel-forming ability of myofibrillar proteins, which coincided with the progress of the intra- and intermolecular cross-linking reactions as well as with ATPase activity changes.

Related Papers

• → Structure and Function of the Two Heads of the Myosin Molecule(1976)13 cited
• → Association and dissociation of the thick and thin filaments within myofibrils in conditions of “contraction” and “relaxation”(1969)8 cited
• → Reaction Intermediates Formed by Myofibrils during the ATPase Reaction under Relaxed Conditions1(1989)3 cited
• 닭고기의 근원섬유 단백질에 관한 연구 - 2. 골격근 부위별로 추출한 근원섬유, 액토미오신 및 미오신의 ATPase 활성 비교(1985)
• → Regulation of troponin and myosin conformation in thin- and thick-filament domains in the sarcomere of skeletal muscle myofibrils(2023)