Linked Life Data

7876123

Source:http://linkedlifedata.com/resource/pubmed/id/7876123

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1995-3-31
pubmed:databankReference
pubmed:abstractText
Fluorescence steady-state and lifetime measurements have been performed that permit the differentiation of the 2 intrinsic tryptophan residues in bovine low molecular weight phosphotyrosyl protein phosphatase (BPTP). Spectral information was obtained by use of two single-tryptophan mutant proteins, W39F and W49F, and the double mutant protein W39,49F. Fluorescence measurements show that Trp39 is characterized by a large blue shift, a low quantum yield, and a shorter mean lifetime compared to Trp49. Solute fluorescence quenching studies of W39F reveal that Trp49 is highly exposed to the aqueous environment. In contrast, Trp39 is situated within a hydrophobic core and is only partially accessible to quenching agents such as acrylamide, iodide ion, and cesium ion. The fluorescence contributions of Trp39 and Trp49 are additive, and their sum is equivalent to that observed for wild type BPTP. Calculated intramolecular distances between Trp39 or Trp49 and a 5-[[(acetylamino)-ethyl]amino]naphthalene-1- sulfonate group covalently bound at Cys12 or Cys17 of the respective protein mutants, place Trp49 within 10 A and Trp39 at least 20 A from the active site. The fluorescence decay of the single tryptophan mutants and, surprisingly, wild type BPTP were each adequately fitted as biexponentials. The latter is a consequence of the imprecision involved in determining actual minima in a three- and four-exponential fitting. Comparison of quenching results of wild type BPTP with those of the single tryptophan mutant proteins indicates that minor fluorescence components, easily resolved using a biexponential fitting for the mutant proteins, are unresolvable for wild type BPTP. These minor components skewed the weighted magnitudes and induced perturbations in lifetimes for the tryptophan fluorescence of wild type BPTP, which directly influenced the calculated values of Ksv and kq.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
24
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3809-15
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Fluorescence resolution of the intrinsic tryptophan residues of bovine protein tyrosyl phosphatase.
pubmed:affiliation
Department of Chemistry, Purdue University, West Lafayette, Indiana 47907.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.