Molt cycle-associated changes in calcium-dependent proteinase activity that degrades actin and myosin in crustacean muscle
The role of calcium-dependent proteinase (CDP) in the proecdysial atrophy of crustacean claw muscle has been investigated. During atrophy the molar ratio of actin to myosin heavy chain decreased 31%, confirming earlier ultrastructural observations that the ratio of thin:thick myofilaments declined from 9:1 to 6:1 (D.L. Mykles and D.M. Skinner, 1981, J. Ultrastruct. Res. 75, 314 to 325). The release of TCA-soluble material in muscle homogenates at neutral pH was stimulated by Ca/sup 2 +/ and completely inhibited by EGTA. The specific degradation of the major myofibrillar proteins (actin, myosin heavy and light chains, paramyosin, tropomyosin, troponin-T, and troponin-I) was demonstrated by SDS-polyacrylamide gel electrophoresis. Proteolytic activity was more than twofold greater in proecdysial muscle homogenates. Degradation of myofibrillar proteins was inhibited by EGTA, and the two inhibitors of crysteine proteinases, leupeptin, and antipain, but not pepstatin, an inhibitor of aspartic proteinases. Unlike CDPs from vertebrate muscle, the CDP(s) in crab claw muscle degrades actin and myosin in addition to other myofibrillar proteins.
- Research Organization:
- Oak Ridge National Lab., TN
- DOE Contract Number:
- W-7405-ENG-26
- OSTI ID:
- 6795368
- Journal Information:
- Dev. Biol.; (United States), Vol. 92
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ACTIN
PROTEOLYSIS
MYOSIN
CALCIUM
CRUSTACEANS
ELECTROPHORESIS
ENZYME ACTIVITY
ENZYME INHIBITORS
EXPERIMENTAL DATA
HYDROLASES
LIFE CYCLE
MUSCLES
ALKALINE EARTH METALS
ANIMALS
AQUATIC ORGANISMS
ARTHROPODS
CHEMICAL REACTIONS
DATA
DECOMPOSITION
ELEMENTS
ENZYMES
GLOBULINS
INFORMATION
INVERTEBRATES
METALS
NUMERICAL DATA
ORGANIC COMPOUNDS
PROTEINS
550200* - Biochemistry