Galactosyltransferase activities in pancreas, liver and gut of the developing rat |
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Authors: | D M Carlson J David W J Rutter |
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Institution: | Department of Biochemistry and Biophysics, University of California, San Francisco, California 94122 USA |
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Abstract: | Two galactosyltransferase activities (1 and 2) were measured in the pancreas, liver and gut of the developing rat embryo. 1. N-Acetylglucosamine:Galactosyltransferase. UDP 14C]galactose + N-acetylglucosamine → 14C]galactosyl-β-(1 → 4)-N-acetylglucosamine + UDP. 2. N-Acetylgalactosamine-protein:Galactosyltransferase. UDP 14C]galactose + N-acetylgalactosamine-protein → 14C]galactosyl-β-(1 → 3)-N-acetylgalactosamine-protein + UDP. Galactosyltransferases 1 and 2 increased in the pancreas, about 10- and 40-fold in specific activity, respectively, from 11 to 12 days in utero to birth. During this period the activities of both transferases in the liver were somewhat variable, but showed no definite trend. A drop in the level of galactosyltransferase 1 in the pancreas occurred at birth or shortly thereafter. The “Golgimarker” enzyme for liver, galactosyltransferase 1, may be absent or present at low levels in adult rat pancreas.Zymogen granule membrane preparations apparently are devoid of these galactosyltransferase activities. Bromodeoxyuridine, which inhibits the development of the synthetic capability of the specific exocrine proteins, had essentially no effect on the normal accretion of the galactosyltransferase activities in organ cultures of pancreatic rudiments from 13-day rat embryos. |
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Keywords: | Requests for reprints should be addressed to Don M Carlson Department of Biochemistry School of Medicine Case Western Reserve University Cleveland Ohio 44106 |
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