TY - JOUR
T1 - Mammalian skeletal muscle myosin light chain kinases. A comparison by antiserum cross-reactivity
AU - Nunnally, M. H.
AU - Stull, J. T.
N1 - Copyright:
Copyright 2004 Elsevier B.V., All rights reserved.
PY - 1984
Y1 - 1984
N2 - Purified myosin light chain kinases from skeletal muscle are reported to be significantly smaller (M(r) = 75,000-90,000) than the kinases purified from smooth muscle (M(r) = 130,000-155,000). It has been suggested that the smaller kinases from striated muscle are proteolytic fragments of a larger enzyme which is homologous, if not identical, to myosin light chain kinase from smooth muscle. Therefore, we have used an anti-serum to rabbit skeletal muscle myosin light chain kinase and Western blot analysis to compare the subunit molecular weight of the kinase in skeletal muscle extracts of several mammalian species. In rabbit skeletal muscle, the antiserum only recognized a polypeptide of M(r) = 87,000, with no indication that this polypeptide was a proteolyzed fragment of a larger protein. The apparent molecular weights observed in different animal species were 75,000 (mouse), 83,000 (guinea pig), 82,000 (rat), 87,000 (rabbit), 100,000 (dog), and 108,000 (steer). The molecular weight of myosin light chain kinase was constant within an animal species, regardless of skeletal muscle fiber type. The antiserum inhibited the catalytic activity of skeletal muscle myosin light chain kinase. Similar antibody dilution curves for inhibition of myosin light chain kinase activity in extracts were observed for all animal species (rabbit, rat, mouse, guinea pig, dog, cat, steer, and chicken) and different fibers (slow twitch oxidative, fast twitch oxidative glycolytic, and fast twitch glycolytic) tested. The antiserum did not inhibit the activity of rabbit smooth muscle myosin light chain kinase. These results suggest that there may be at least two classes of muscle myosin light chain kinase represented in skeletal and smooth muscles, respectively.
AB - Purified myosin light chain kinases from skeletal muscle are reported to be significantly smaller (M(r) = 75,000-90,000) than the kinases purified from smooth muscle (M(r) = 130,000-155,000). It has been suggested that the smaller kinases from striated muscle are proteolytic fragments of a larger enzyme which is homologous, if not identical, to myosin light chain kinase from smooth muscle. Therefore, we have used an anti-serum to rabbit skeletal muscle myosin light chain kinase and Western blot analysis to compare the subunit molecular weight of the kinase in skeletal muscle extracts of several mammalian species. In rabbit skeletal muscle, the antiserum only recognized a polypeptide of M(r) = 87,000, with no indication that this polypeptide was a proteolyzed fragment of a larger protein. The apparent molecular weights observed in different animal species were 75,000 (mouse), 83,000 (guinea pig), 82,000 (rat), 87,000 (rabbit), 100,000 (dog), and 108,000 (steer). The molecular weight of myosin light chain kinase was constant within an animal species, regardless of skeletal muscle fiber type. The antiserum inhibited the catalytic activity of skeletal muscle myosin light chain kinase. Similar antibody dilution curves for inhibition of myosin light chain kinase activity in extracts were observed for all animal species (rabbit, rat, mouse, guinea pig, dog, cat, steer, and chicken) and different fibers (slow twitch oxidative, fast twitch oxidative glycolytic, and fast twitch glycolytic) tested. The antiserum did not inhibit the activity of rabbit smooth muscle myosin light chain kinase. These results suggest that there may be at least two classes of muscle myosin light chain kinase represented in skeletal and smooth muscles, respectively.
UR - http://www.scopus.com/inward/record.url?scp=0021350780&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0021350780&partnerID=8YFLogxK
M3 - Article
C2 - 6546381
AN - SCOPUS:0021350780
SN - 0021-9258
VL - 259
SP - 1776
EP - 1780
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 3
ER -