In vivo effect of a beta-adrenergic agonist on activity of calcium-dependent proteinases, their specific inhibitor, and cathepsins B and H in skeletal muscle.
DEAE-Sephacel and phenyl-Sepharose chromatography were compared as methods for separating and quantitatively isolating calpain I, calpain II, and calpastatin from lamb muscle extracts. DEAE-Sephacel chromatography gave greater than 90% recovery of all three proteins, while phenyl-Sepharose gave only 70, 66, and 48% of the DEAE recovery of calpain I, calpain II, and calpastatin, respectively. Additionally, DEAE-Sephacel chromatography was shown to effectively separate calpastatin and calpain I. Consequently DEAE-Sephacel appears to be superior to phenyl-Sepharose for quantitative isolation of the components of the calcium-dependent proteinase system from muscle extracts. Dietary administration of beta-agonist (L-644, 969; Merck Sharpe & Dohme Research Laboratories) decreases extractable calpain I activity in lamb longissimus dorsi (LD) muscle by 10-14% (P less than 0.05), increases calpain II activity by 34-42% (P less than 0.001), and increases calpastatin activity by 59-75% (P less than 0.001). Additionally, net cathepsin B activity is reduced by 30% (P less than 0.05) in the LD of beta-agonist-treated lambs. Reduced activity of the calcium-dependent or catheptic proteinase systems may contribute to the increased protein accretion in muscles of beta-agonist-treated lambs.
Kretchmar
D H
DH
Department of Animal Science, University of Minnesota, St. Paul 55108.
Hathaway
M R
MR
Epley
R J
RJ
Dayton
W R
WR
D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000818:Animals; D002135:Calcium-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D002154:Calpain / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D002401:Cathepsin B / Q000302:isolation & purification / Q000378:metabolism*; D056655:Cathepsin H; D002403:Cathepsins / Q000302:isolation & purification / Q000378:metabolism*; D002852:Chromatography, Ion Exchange; D003546:Cysteine Endopeptidases; D005260:Female; D007527:Isoenzymes / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D009132:Muscles / Q000201:enzymology*; D011725:Pyridines / Q000494:pharmacology*; D012016:Reference Values; D012756:Sheep
D000318:Adrenergic beta-Agonists; D002135:Calcium-Binding Proteins; D007527:Isoenzymes; D011725:Pyridines; C061557:6-amino-alpha-(((1-methyl-3-phenylpropyl)amino)methyl)-3-pyridine methanol; C033668:calpastatin; D002403:Cathepsins; D002154:Calpain; D003546:Cysteine Endopeptidases; D002401:Cathepsin B; D056655:Cathepsin H