Linked Life Data

3364975

Source:http://linkedlifedata.com/resource/pubmed/id/3364975

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1988-6-2
pubmed:abstractText
A soluble enzyme which catalyzes the transfer of the methyl group from S-adenosyl-L-methionine to the nitrogen atom of pyridine-3-carboxylic acid (nicotinic acid) could be detected in protein preparations from heterotrophic cell suspension cultures of soybean (Glycine max L.). Enzyme activity was enriched nearly 100-fold by ammonium sulfate precipitation, gel filtration, and ion-exchange chromatography to study kinetic properties. S-adenosyl-L-methionine:nicotinic acid-N-methyltransferase (EC 2.1.1.7) showed a pH optimum at pH 8.0 and a temperature optimum between 35 and 40 degrees C. The apparent KM values were determined to be 78 microM for nicotinic acid and 55 microM for the cosubstrate. S-Adenosyl-L-homocysteine was a competitive inhibitor of the methyltransferase with a KI value of 95 microM. The native enzyme had a molecular mass of about 90 kDa. The catalytic activity was inhibited by reagents blocking SH groups, whereas other divalent cations did not significantly influence of the enzyme reaction. The purified methyltransferase revealed a remarkable specificity for nicotinic acid. No other pyridine derivative was a suitable methyl group acceptor. To study a potential methyltransferase activity with nicotinamide as substrate, an additional purification step was necessary to remove nicotinamide amidohydrolase activity from the enzyme preparation. This was achieved by affinity chromatography on S-adenosyl-L-homocysteine-Sepharose thus leading to a 580-fold purified enzyme which showed no methyltransferase activity toward nicotinamide as substrate.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0003-9861
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
262
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
445-54
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Purification and properties of S-adenosyl-L-methionine:nicotinic acid-N-methyltransferase from cell suspension cultures of Glycine max L.
pubmed:affiliation
Lehrstuhl für Biochemie der Pflanzen, Westfälische Wilhelms-Universität Münster, Federal Republic of Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't