Interaction between vertebrate skeletal and uterine muscle myosins and light meromyosins.

Abstract

No hybridization of uterine and skeletal myosin occurred at pH 6.0 although previous studies showed that hybridization does occur at pH 6.5. Hybridization of uterine and skeletal light meromyosins (LMM) occurs at pH 7.0 but not at pH 6.0, which is analogous to the hybridization of myosins. In hybridized paracrystals there is a uniform distribution of uterine and skeletal LMM molecules because all the paracrystals have only 1 axial repeat pattern. It is highly likely that in hybridized filaments the 2 myosins are also uniformly distributed throughout the filaments. The 14 nm repeat of white bands observed in paracrystals of uterine LMM formed at pH 6.0, compared with the 14 nm repeat of dark bands observed with skeletal LMM under the same conditions, probably reflects differences in surface change density along the different LMM molecules. [Chicken and rabbit were studied.].