Rat skeletal muscle membrane associated carbonic anhydrase is 39-kDa, glycosylated, GPI-anchored CA IV.
Sarcolemmal membrane vesicle preparations from white and red muscles of rat were found to contain a carbonic anhydrase which was indistinguishable from carbonic anhydrase IV from rat lung. This isozyme appears to account for all of the carbonic anhydrase activity in the sarcolemmal vesicle preparations. Digestion of 39-kDa CA IV with endoglycosidase F reduced the Mr to 36 kDa, suggesting that it contains one N-linked oligosaccharide. Treatment of sarcolemmal vesicles with phosphatidylinositol-specific phospholipase C released all of the activity, indicating that the enzyme is anchored to membranes by a phosphatidylinositol-glycan linkage. White muscle sarcoplasmic reticulum vesicles also contain a small amount of 39-kDa CA IV-type enzyme. A 52-kDa polypeptide in sarcoplasmic reticulum membranes cross-reacts with anti-human CA II and anti-rat CA II antisera, but does not bind to the sulfonamide affinity column. This cross-reacting polypeptide has no detectable CA activity.
Waheed
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A
Edward A. Doisy Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, Missouri 63104.
Zhu
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XL
Sly
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WS
Wetzel
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P
Gros
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G
D000818:Animals; D002256:Carbonic Anhydrases / Q000737:chemistry* / Q000378:metabolism; D005260:Female; D006017:Glycolipids / Q000032:analysis*; D006023:Glycoproteins / Q000737:chemistry / Q000378:metabolism; D006026:Glycoside Hydrolases; D006031:Glycosylation; D017261:Glycosylphosphatidylinositols; D015151:Immunoblotting; D007527:Isoenzymes / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism; D008970:Molecular Weight; D009132:Muscles / Q000201:enzymology*; D010716:Phosphatidylinositols / Q000032:analysis*; D051381:Rats; D011919:Rats, Inbred Strains; D012508:Sarcolemma / Q000201:enzymology*; D012519:Sarcoplasmic Reticulum / Q000201:enzymology
D006017:Glycolipids; D006023:Glycoproteins; D017261:Glycosylphosphatidylinositols; D007527:Isoenzymes; D008565:Membrane Proteins; D010716:Phosphatidylinositols; D006026:Glycoside Hydrolases; D002256:Carbonic Anhydrases