2024-03-28T13:59:37Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/532732022-11-17T02:08:08Zhdl_2115_20049hdl_2115_141Ca2+-binding properties and regulatory roles of lobster troponin C sites II and IVTanaka, HiroyukiTakahashi, HirokiOjima, TakaoTroponinMuscleCa2+-regulationInvertebrateArthropodIsoform464Invertebrate troponin C typically contains Ca2+-specific binding sites, sites II and IV, in the N- and C-terminal domains, respectively. To investigate the roles of these sites for Ca2+-dependent regulation of muscle contraction, we generated lobster troponin C mutants, and analyzed their Ca2+-binding properties and regulatory effects on actomyosin-tropomyosin Mg-ATPase activity. The results suggest that Ca2+ binding to site IV is responsible for regulation at relatively low Ca2+ concentrations, while site II has an essential role in full activation at higher Ca2+ concentrations. (C) 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.Elsevier science bvJournal Articleapplication/pdfhttp://hdl.handle.net/2115/53273https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/53273/1/Manuscript.pdf0014-5793AA00642943Febs letters58716261226162013-08-19enginfo:pmid/23831063info:doi/10.1016/j.febslet.2013.06.042author