Linked Life Data

967895

Source:http://linkedlifedata.com/resource/pubmed/id/967895

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1976-11-21
pubmed:abstractText
The presence of a single cysteine in the sweet-tasting protein monellin was confirmed by titrations with p-hydroxymercuribenzoate (PHMB) and 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB). The sulfhydryl group in native monellin reacts very slowly with each of these reagents, indicating that the sulfhydryl is relatively inaccessible. In the presence of either 6 M guanidine-HCl, 8 M urea, or 1% sodium dodecyl sulfate, the rate of reaction of the sulfhydryl group with titrant is dramatically increased. Under a variety of conditions, the presence of 1 mole of sulfhydryl per mole of protein (of molecular weight 10,700) was found. Reaction of the sulfhydryl by titration with PHMB or DTNB leads to loss of sweetness. The free sulfhydryl is also lost by carboxymethylation of monellin in the presence of guanidine-HCl, yielding a protein that is not sweet. Exposure to air in the presence of denaturant leads to a decrease in the sweetness of monellin. Sweetness of the PHMB-reacted monellin can be recovered upon treatment of the protein with mercaptoethanol, and the partial loss of sweetness that occurs with air exposure is lessened in the presence of mercaptoethanol. It is postulated that alteration of the single sulfhydryl group of monellin leads to a change in the tertiary structure of the protein and hence its sweet taste.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0037-9727
pubmed:author
pubmed:issnType
Print
pubmed:volume
152
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
635-40
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1976
pubmed:articleTitle
The sulfhydryl group of monellin: its chemical reactivity and importance to the sweet taste.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.