Expression of hybrid isomyosins in human skeletal muscle.
Wada, Masanobu, Tadashi Okumoto, Kyoko Toro, Kazumi Masuda, Toru
Fukubayashi, Kunio Kikuchi, Shigemitsu Niihata, and Shigeru Katsuta.
Faculty of Integrated Arts and Sciences, Hiroshima University,
Higashihiroshima-shi Hiroshima-ken, Japan, Institute of Health and
Sports Sciences, University of Tsukuba, Tennodai, Tsukuba-shi,
Ibaraki-ken, Japan, Department of Life Sciences, University of Tokyo,
Komaba, Meguro-ku, Tokyo, Japan
APStracts 3:0172C, 1996.
Myosin of human skeletal muscles was analyzed by means of several
electrophoretic techniques. Myosin heavy chain (HC) IIA- and HCIIB
-based isomyosins were identified by pyrophosphate polyacrylamide gel
electrophoresis (PP-PAGE). The electrophoretic mobilities of these
fast isomyosins differed in the order HCIIA triplets < HCIIB
triplets. In order to determine the subunit composition of myosin
molecules that function in intact muscle, two-dimensional
electrophoresis in which the first and second dimensions were PP-PAGE
and sodium dodecylsulfate polyacrylamide gel electrophoresis,
respectively, was also performed. Slow isomyosin contained, in
addition to slow light chain (LC) and HCI isoforms, appreciable
amounts of LC2f, HCIIA, and HCIIB isoforms, and fast isomyosin
consists of LC2s and HCI isoforms as well as fast LC and HC isoforms.
Without consideration of HC- and slow alkali LC-heterodimers, at
least 31 possible isomyosins are derived from these finding on the
subunit composition of isomyosins in human skeletal muscle.
Received 5 February 1996; accepted in final form 6 May 1996.
APS Manuscript Number C69-6.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 5 June 96