Linked Life Data

2125471

Source:http://linkedlifedata.com/resource/pubmed/id/2125471

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
38
pubmed:dateCreated
1991-2-28
pubmed:abstractText
The dolichyl-P-mannose:dolichyl-PP-heptasaccharide alpha-mannosyltransferase (2.4.1.130), which catalyzes the transfer of mannose from dolichyl-P-mannose to the Man5(GlcNAc)2-PP-dolichol acceptor glycolipid, was solubilized from pig aorta microsomes with 0.5% NP-40 and purified 985-fold by a variety of conventional methods. The partially purified enzyme had a pH optimum of 6.5 and required Ca2+, at an optimum concentration of 8-10 mM, for activity. Mn2+ was only 20% as effective as Ca2+, and Mg2+ was inhibitory. The mannosyltransferase activity was also inhibited by the addition of EDTA to the enzyme, but this inhibition was fully reversible by the addition of Ca2+. The enzyme was quite specific for dolichyl-P-mannose as the mannosyl donor and Man5(GlcNAc)2-PP-dolichol as the mannosyl acceptor. The Km values for dolichyl-P-mannose and the acceptor lipid Man5(GlcNAc)2-PP-dolichol were 1.8 and 1.6 microM. On Bio-Gel P-4 columns and by HPLC, the radiolabeled oligosaccharide formed during incubation of dolichyl-P-[14C]mannose and unlabeled Man5(GlcNAc)2-PP-dolichol with the purified enzyme behaved like Man6(GlcNAc)2. This octasaccharide was susceptible to digestion by endoglucosaminidase H, indicating that the newly added mannose was attached to the 6-linked mannose in an alpha 1,3-linkage. This linkage was further confirmed by acetolysis of the oligosaccharide product [i.e., Man6(GlcNAc)2], which gave a labeled disaccharide as the major product (greater than 90%).
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
29
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8901-7
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Purification and characterization of dolichyl-P-mannose:Man5(GlcNAc)2-PP-dolichol mannosyltransferase.
pubmed:affiliation
Department of Biochemistry, University of Texas Health Science Center, San Antonio 78284.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't