![]()
|
|
||||||||
JBC, Vol. 250, Issue 11, 4278-4284, Jun, 1975
M. K. Reddy, J. D. Etlinger, M. Rabinowitz, D. A. Fischman and R. Zak
A calcium-activated factor (CaAF) has been isolated and partially purified from the post-myofibrillar supernatant fraction of rabbit skeletal muscle. The 200-fold purified CaAF hydrolyzed denatured casein, [3-H]acetyl hemoglobin, and N-ethyl[3-H]maleimide-labeled alpha-actinin. The proteolytic activity has a pH optimum at 6.9 and is dependent on the presence of Ca2+ (optimum concentration, 10 mM). Digestion of isolated myofibrils with CaAF results in removal of Z-lines and in a parallel loss of a 90, 000-dalton protein that has a mobility identical with that of alpha-actinin as determined by polyacrylamide gel electrophoresis. A protein with the properties of alpha-actinin (identical electrophoretic mobility, and ability to accelerate the Mg2+-activated ATPase of reconstituted actomyosin) was isolated from the supernatant of CaAF-treated myofibrils. The release of alpha-actinin from myofibrils by the calcium-activated neutral protease occurs in the absence of detectable change in the electrophoretic profiles of the other myofibrillar proteins, or in the ethylene glycol bis(beta-aminoethyl ether)-N, N' tetraacetic acid (EGTA) sensitivity of Mg2+-activated ATPase. In contrast to the specific removal of Z-lines and of alpha-actinin by CaAF, trypsin treatment of myofibrils results in extensive degradation of myosin heavy chains and of the inhibitory component of troponin (TN-I), and in loss of EGTA sensitivity of myofibrillar ATPase. The degradation of TN-I and loss of EGTA sensitivity occur before the Z-line disappearance.
This article has been cited by other articles:
![]() |
D. V. Baewer, M. Hoffman, J. G. Romatowski, J. L. W. Bain, R. H. Fitts, and D. A. Riley Passive stretch inhibits central corelike lesion formation in the soleus muscles of hindlimb-suspended unloaded rats J Appl Physiol, September 1, 2004; 97(3): 930 - 934. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. E. Van Eyk, F. Powers, W. Law, C. Larue, R. S. Hodges, and R. J. Solaro Breakdown and Release of Myofilament Proteins During Ischemia and Ischemia/Reperfusion in Rat Hearts : Identification of Degradation Products and Effects on the pCa-Force Relation Circ. Res., February 9, 1998; 82(2): 261 - 271. [Abstract] [Full Text] [PDF] |
||||
![]() |
T.-X. JIANG, W. DARLENE REID, A. BELCASTRO, and J. D. ROAD Load Dependence of Secondary Diaphragm Inflammation and Injury after Acute Inspiratory Loading Am. J. Respir. Crit. Care Med., January 1, 1997; 157(1): 230 - 236. [Abstract] [Full Text] |
||||
![]() |
M. J. Spencer, D. E. Croall, and J. G. Tidball Calpains Are Activated in Necrotic Fibers from mdx Dystrophic Mice J. Biol. Chem., May 5, 1995; 270(18): 10909 - 10914. [Abstract] [Full Text] [PDF] |
||||
![]() |
A Stracher, E. McGowan, and S. Shafiq Muscular dystrophy: inhibition of degeneration in vivo with protease inhibitors Science, April 7, 1978; 200(4337): 50 - 51. [Abstract] [PDF] |
||||
![]() |
P Libby and A. Goldberg Leupeptin, a protease inhibitor, decreases protein degradation in normal and diseased muscles Science, February 3, 1978; 199(4328): 534 - 536. [Abstract] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Molecular and Cellular Proteomics |
| Journal of Lipid Research | ASBMB Today |