Linked Life Data

235283

Source:http://linkedlifedata.com/resource/pubmed/id/235283

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1975-7-7
pubmed:abstractText
The buoyant density titration curves of native and carbamylated bovine serum mercaptalbumin were measured throughout the pH range 5.3-12.7. Large increments in the buoyant density were observed above pH 10, with inflection pH values of 11.2 and 11.4 for native and carbamylated bovine serum mercaptalbumin, respectively. For the modified protein in which 25 out of 58 lysine residues were carbamylated, the buoyant densities were 0.048 g/ml higher at neutral pH and 0.024 g/ml higher at the extrapolated pH 13. The carbamyl groups apparently produce a larger residual density at pH 13 than they did in the case of ovalbumin. Homopolymer buoyant density titration data were demonstrated to be of value in calculating the contributions of titratable residues to the buoyant density of both proteins. The buoyant density increment at high pH was due largely to the deprotonation of the lysines as indicated by the diminished change in buoyant density between pH 10 and 12.7 for the modified protein. These density changes were attributable primarily to a gain of cesium ions. The limited modification of the lysine residues under mild reaction conditions and the rather high intrinsic dissociation constant of tyrosine residues in mercaptalbumin may indicate a preferential modification of easily accessible lysine residues. Phenolic deprotonation is facilitated by the neutralization of normally charged lysine residues and demonstrates ionic interactions between internal lysines and certain carboxyl and tyrosine residues thereby stabilizing the native state of the protein.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
14
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1205-10
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1975
pubmed:articleTitle
The buoyant titration of native and carbamylated bovine serum mercaptalbumin.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.