Huang Y P, Seguro K, Motoki M, Tawada K
Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Fukuoka.
J Biochem. 1992 Aug;112(2):229-34. doi: 10.1093/oxfordjournals.jbchem.a123882.
The action on muscle proteins of microbial transglutaminase (MTGase), which catalyzes the formation of a "zero-length" covalent cross-link between glutamine and lysine residues in peptides, was studied in order to define a basis for future application of MTGase cross-linking to the study of muscle protein interaction. We examined the cross-linking of skeletal muscle myosin, myosin subfragments, actin, and myofibrils by treatment with MTGase and the possible side-effects of the cross-linking on the enzymic activity of myosin, and found that the rod portions of myosin in myosin filaments were quickly cross-linked to each other by the action of MTGase, but myosin subfragment 1 was not cross-linked to actin. The MgATPase activities at 0.5 M KCl of myosin, heavy meromyosin, subfragment 1, and subfragment 1-actin were not significantly affected by the MTGase reaction. A very small fraction of the head portion of heavy meromyosin was cross-linked to actin in their rigor complexes by MTGase, and the ATPase activity at 0.5 M KCl of the cross-linked heavy meromyosin-actin complexes was slightly enhanced.
研究了微生物转谷氨酰胺酶（MTGase）对肌肉蛋白的作用，该酶催化肽中谷氨酰胺和赖氨酸残基之间形成“零长度”共价交联，以便为MTGase交联在肌肉蛋白相互作用研究中的未来应用确定基础。我们通过用MTGase处理来检测骨骼肌肌球蛋白、肌球蛋白亚片段、肌动蛋白和肌原纤维的交联以及交联对肌球蛋白酶活性可能产生的副作用，发现肌球蛋白丝中的肌球蛋白杆状部分通过MTGase的作用迅速相互交联，但肌球蛋白亚片段1未与肌动蛋白交联。在0.5 M KCl条件下，肌球蛋白、重酶解肌球蛋白、亚片段1和亚片段1 - 肌动蛋白的MgATPase活性不受MTGase反应的显著影响。在其强直复合物中，重酶解肌球蛋白头部的一小部分通过MTGase与肌动蛋白交联，并且交联的重酶解肌球蛋白 - 肌动蛋白复合物在0.5 M KCl条件下的ATPase活性略有增强。
