Linked Life Data

8910350

Source:http://linkedlifedata.com/resource/pubmed/id/8910350

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
44
pubmed:dateCreated
1996-12-26
pubmed:abstractText
The Saccharomyces cerevisiae alpha1,2-mannosidase, which removes one specific mannose residue from Man9GlcNAc2 to form Man8GlcNAc2, is a member of a family of alpha1,2-mannosidases with similar amino acid sequences. The yeast alpha1,2-mannosidase contains five cysteine residues, three of which are conserved. Recombinant yeast alpha1, 2-mannosidase, produced as the soluble catalytic domain, was shown to contain two disulfide bonds and one free thiol group using 2-nitro-5-thiosulfobenzoate and 5,5'-dithiobis(2-nitrobenzoate), respectively. Cys485 contains the free thiol group, as demonstrated by sequencing of labeled peptides following modification with [3H]ICH2COOH and by high performance liquid chromatography/mass spectrometry tryptic peptide mapping. A Cys340-Cys385 disulfide was demonstrated by sequencing a purified peptide containing this disulfide and by tryptic peptide mapping. Cys468 and Cys471 were not labeled with [3H]ICH2COOH and a peptide containing these two residues was identified in the tryptic peptide map, showing that Cys468 and Cys471 form the second disulfide bond. The alpha1, 2-mannosidase loses its activity in the presence of dithiothreitol with first order kinetics, suggesting that at least one disulfide bond is essential for activity. Mutagenesis of each cysteine residue to serine showed that Cys340 and Cys385 are essential for production of recombinant enzyme, whereas Cys468, Cys471, and Cys485 are not required for production and enzyme activity. These results indicate that the sensitivity to dithiothreitol is due to reduction of the Cys340-Cys385 disulfide. Since Cys340 and Cys385 are conserved residues, it is likely that this disulfide bond is important to maintain the correct structure in the other members of the alpha1, 2-mannosidase family.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
271
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
27615-22
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:8910350-Amino Acid Sequence, pubmed-meshheading:8910350-Animals, pubmed-meshheading:8910350-Binding Sites, pubmed-meshheading:8910350-Carbohydrate Sequence, pubmed-meshheading:8910350-Chromatography, High Pressure Liquid, pubmed-meshheading:8910350-Conserved Sequence, pubmed-meshheading:8910350-Cysteine, pubmed-meshheading:8910350-Disulfides, pubmed-meshheading:8910350-Dithionitrobenzoic Acid, pubmed-meshheading:8910350-Dithiothreitol, pubmed-meshheading:8910350-Drosophila, pubmed-meshheading:8910350-Humans, pubmed-meshheading:8910350-Mannosidases, pubmed-meshheading:8910350-Mice, pubmed-meshheading:8910350-Molecular Sequence Data, pubmed-meshheading:8910350-Mutagenesis, Site-Directed, pubmed-meshheading:8910350-Peptide Fragments, pubmed-meshheading:8910350-Peptide Mapping, pubmed-meshheading:8910350-Polymerase Chain Reaction, pubmed-meshheading:8910350-Polysaccharides, pubmed-meshheading:8910350-Rabbits, pubmed-meshheading:8910350-Recombinant Proteins, pubmed-meshheading:8910350-Saccharomyces cerevisiae, pubmed-meshheading:8910350-Sequence Homology, Amino Acid
pubmed:year
1996
pubmed:articleTitle
Role of the cysteine residues in the alpha1,2-mannosidase involved in N-glycan biosynthesis in Saccharomyces cerevisiae. The conserved Cys340 and Cys385 residues form an essential disulfide bond.
pubmed:affiliation
McGill Cancer Centre, McGill University, Montréal, Québec, Canada H3G 1Y6. annette@medcor.mcgill.ca
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't