meromyosinn.
/ˌmɛrə(ʊ)ˈmʌɪə(ʊ)sɪn/, U.S. /ˌmɛroʊˈmaɪəs(ə)n/ Biochemistry.
Either of the two fractions obtained from myosin by the action of trypsin and certain other proteolytic enzymes, of which the heavier fraction (in full heavy meromyosin) consists of the globular heads and a small section of the helical tail of the myosin molecule, and the lighter fraction (in full light meromyosin) consists of the remainder of the tail.
ΚΠ
1952 A. G. Szent-Györgyi in Federation Proc. (Federation Amer. Soc. Exper. Biol.) 11 297/1 The fraction with the lower sedimentation constant (meromyosin-L), has the peculiar solubility of myosin... The fraction with the higher S20 (meromyosin-H), is soluble at any KCl concentration at pH 7 and precipitates at pH 5·1.
1966 McGraw-Hill Yearbk. Sci. & Technol. 258/2 These experiments have shown that the myosin molecules aggregate in an antiparallel, overlapping fashion, the straight L-meromyosin forming the backbone of the filament and the H-meromyosin constituting the cross bridges.
1988 P. W. Kuchel et al. Schaum's Outl. Theory & Probl. Biochem. v. 127 The protease trypsin cleaves a sensitive region in the tail to produce highly α-helical light meromyosin (LMM) and heavy meromyosin (HMM).
2000 Jrnl. Biol. Chem. 275 28045/1 Several of the heavy meromyosin mutants..showed an increase in actin filament velocity in a motility assay and an enhanced actin-activated ATPase activity.
This entry has been updated (OED Third Edition, September 2001; most recently modified version published online March 2022).
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n.1952