Linked Life Data

3611084

Source:http://linkedlifedata.com/resource/pubmed/id/3611084

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
22
pubmed:dateCreated
1987-9-17
pubmed:abstractText
The role of asparagine-linked oligosaccharides for the mechanism of protein folding was investigated. We compared the stability and folding kinetics for two sets of pancreatic ribonucleases (RNases) with identical amino acid sequences and differences in glycosylation. First the folding of RNases A (carbohydrate free) and B (a single N-linked oligosaccharide) from bovine pancreas was investigated. The kinetics of refolding were identical under a wide range of conditions. The rate of unfolding by guanidinium chloride was decreased in RNase B. In further experiments the folding of porcine RNase (three carbohydrate chains at Asn-21, -34, and -76) was compared with the corresponding data for the deglycosylated protein. Even for this RNase with almost 40% carbohydrate content the mechanism of refolding is independent of glycosylation. Although the folding mechanism is conserved, the rates of individual steps in folding are decreased about 2-fold upon deglycosylation. We interpret this to originate from a slight destabilization of folding intermediates by carbohydrate depletion. In control experiments with nonglycosylated bovine RNase A it was ascertained that treatment with HF (as used for deglycosylation) did not affect the folding kinetics. The in vitro folding mechanism of glycosylated RNases apparently does not depend on the presence of N-linked oligosaccharide chains. The information for the folding of glycoproteins is contained exclusively in the protein moiety, i.e. in the amino acid sequence. Carbohydrate chains are attached at chain positions which remain solvent exposed. This ensures that the presence of oligosaccharides does not interfere with correct folding of the polypeptide chain.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
262
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10624-9
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
The mechanism of folding of pancreatic ribonucleases is independent of the presence of covalently linked carbohydrate.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't