Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.4.37 (CNPase)
 539 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A rat brain P3 fraction enriched in ER derived microsomes was centrifuged through a 20-40% linear sucrose gradient in a Beckman Ti-14 Zonal rotor and 11 fractions were obtained. The distribution of marker enzyme activities and protein were determined in these 11 subfractions. NADPH-Cytochrome C reductase, choline phosphotransferase were employed for endoplasmic reticulum, Na+,K+-ATPase, 5'-nucleotidase, and acetylcholinesterase were employed for plasma membrane, 2',3'-cyclic nucleotide phosphohydrolase was employed for myelin. The bulk of the protein was recovered in the 24-34% sucrose fractions, Na+,K+-ATPase, 5'-nucleotidase, and acetylcholinesterase were in the 22-38% sucrose fractions while NADPH-cytochrome C reductase and CNPase were enriched in the 20-22% sucrose fractions. The ethanolamine and the serine base exchange activities had a bimodal distribution, with highest specific activities in sucrose fractions 32-34% and 20-24%. Choline base exchange activity was nearly undetectable in all the fractions. The specific activities of CDP-choline phosphotransferase, and phospholipid-N-methyltransferase were highest in the 20-22% sucrose fraction. Phospholipid-N-methyltransferase activity was significantly stimulated in the presence of exogenous phospholipid acceptors as phosphatidylethanolamine or phosphatidylmonomethylethanolamine or phosphatidyldimethylethanolamine, however, the greatest response was with phosphatidylmonomethylethanolamine. The rat brain P3 fraction yielded a population of a membrane at the light end of the sucrose gradient which has a buoyant density similar to myelin but seemed to be enriched with NADPH cytochrome C reductase and phospholipid modifying enzymes. This is in contrast to liver microsomes submitted to a similar fractionation.
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PMID:Distribution of selected phospholipid modifying enzymes in rat brain microsomal subfractions prepared by density gradient zonal rotor centrifugation. 298 22

Mice with the dysmyelinating mutation shiverer were studied by measuring the activity of two protein methylases and myelin marker enzymes in the brain. It was observed that S-adenosylmethionine:protein-lysine N-methyltransferase (protein methylase III, EC. 2.1.1.43) activity is significantly reduced in phenotypically affected homozygous shiverer (shi/shi) mutant mouse brain compared to the unaffected heterozygous littermate brain. This reduction in enzyme activity is manifested mainly by reduced formation of trimethyllysine during the in vitro methylation of histone. In contrast, myelin marker enzymes such as 2',3'-cyclic nucleotide 3'-phosphohydrolase and 5'-nucleotidase as well as S-adenosyl-methionine:protein-carboxyl O-methyltransferase (protein methylase II, EC. 2.1.1.24) activities were not significantly affected in these strains of mice.
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PMID:Reduced S-adenosylmethionine:protein-lysine N-methyltransferase activity (protein methylase III) in shiverer mutant mouse brain. 303 5