Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1976-8-2
pubmed:abstractText
An enzyme that transfers galactose from UDP-Gal to ganglioside GM2 (Tay-Sachs ganglioside) was concentrated 50 times in Golgi apparatus from rat liver relative to total homogenates. This enzyme required detergents or phospholipids as dispersing agents. Of the numerous detergents tested, sodium taurocholate and Triton CF-54 were most effective in stimulating the reaction. Cardiolipin alone was more effective than any of the detergents tested in stimulating enzyme activity. The pH optimum for the reaction varied with the nature of the dispersing agent. With sodium taurocholate, Triton CF-54 and cardiolipin, the pH optima were 6.2, 5.9, and 5.6, respectively. The enzyme had a nearly absolute requirement for Mn2+, with maximum activity being attained at a concentration of 15 mM Mn2+. Other divalent or trivalent cations were either less effective than Mn2+ or inhibited the transferase reaction. The Km values calculated for UDP-Gal and GM2 were 1.1 X 10(-4) M and 9.9 X 10(-5) M, respectively. The enzyme could not be dissociated from Golgi apparatus fractions by treatment with ultrasound, indicating that it is tightly associated with the membrane and not part of the luminal contents. The newly synthesized GM2, the product of the reaction, was incorporated into or became tightly associated with the membranes of the Golgi apparatus.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0022-2275
pubmed:author
pubmed:issnType
Print
pubmed:volume
17
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
146-53
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1976
pubmed:articleTitle
Ganglioside biosynthesis. Characterization of uridine diphosphate galactose: GM2 galactosyltransferase in golgi apparatus from rat liver.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.