alpha-chymotrypsin and Muscular-Dystrophies

Topics: Amyloidosis; Animals; Arteriosclerosis; Arthritis, Rheumatoid; Blood Coagulation Disorders; Blood Coagulation Factors; Chymotrypsin; Chymotrypsinogen; Diabetes Mellitus; Emphysema; Fibrinolysis; Gastrointestinal Diseases; Humans; Kallikreins; Kidney Diseases; Muscular Dystrophies; Oligopeptides; Peptide Hydrolases; Substrate Specificity; Swine

Six polypeptides resolved by two-dimensional electrophoresis of homogenates from human skeletal muscle have been identified as tropomyosin by electrophoretic and immunochemical methods. The 6 proteins are consistently present in approximately the same abundance in normal biceps, deltoid, gastrocnemius, and quadriceps muscle. Analysis of samples from individuals with Becker's dystrophy, Duchenne dystrophy, limb girdle dystrophy, polymyositis, myopathy related to vitamin E deficiency, type II fiber deficiency, and from an infant with indistinct fiber type differentiation, however, showed quantitative variations in the tropomyosin pattern. Muscle with histochemically demonstrated type II fiber deficiency lacked two of the normal tropomyosin proteins and the type II myosin light chains. Muscles lacking type I myosin light chains were deficient in a different pair of tropomyosin proteins. The results suggest that normal human skeletal muscle contains one major type of tropomyosin protein (beta-tropomyosin) common to both fast and slow fibers, together with two other major proteins (alpha-tropomyosin and alpha'-tropomyosin), one of which is specific to fast fibers and the other to slow fibers. Preliminary data from the reaction of muscle homogenates with alkaline phosphatase indicate that 3 of the 6 tropomyosin polypeptides resolved by two-dimensional electrophoresis are phosphorylated forms of the alpha-, alpha'-, and beta-tropomyosins.

Topics: Adolescent; Adult; Catalysis; Chemical Phenomena; Chemistry; Child; Chymotrypsin; Electrophoresis; Female; Humans; Male; Middle Aged; Muscles; Muscular Diseases; Muscular Dystrophies; Myofibrils; Peptide Hydrolases; Syndrome; Tropomyosin

The primary structure of erythrocyte spectrin bands I and II from controls and patients with Duchenne muscular dystrophy was compared by 2-dimensional peptide mapping. 125I-labelling was done either by the chloramine-T method or using the Bolton and Hunter reagent followed by treatment with trypsin or chymotrypsin, resulting in four different peptide maps from each band of spectrin. Although all the peptide maps of band I were considerably different to those of band II, there were no consistent differences in the maps of bands I and II from controls compared to the corresponding maps from patients with Duchenne muscular dystrophy.

Topics: Chymotrypsin; Electrophoresis, Polyacrylamide Gel; Erythrocytes; Humans; Indicators and Reagents; Membrane Proteins; Muscular Dystrophies; Peptide Fragments; Reference Values; Spectrin; Trypsin