Linked Life Data

2383290

Source:http://linkedlifedata.com/resource/pubmed/id/2383290

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1990-9-11
pubmed:abstractText
Sulfation of tyrosyl residue(s) has been found to be a post-translational modification that precedes the secretion of many biologically active proteins or peptides. In the present paper, we report on the characterization of human liver tyrosylprotein sulfotransferase (TPST), the enzyme responsible for sulfation of tyrosine in proteins. Using poly Glu,Ala,Tyr (6:3:1; EAY) as the model substrate, human liver TPST was recovered in the microsomal fraction after differential centrifugation. This enzyme displayed a pH optimum of 6.4 and was stimulated approximately 2.5-fold in the presence of 0.5% non-ionic detergents, such as Lubrol-PX and Triton X-100. The divalent cation Mn2+ was required for enzymatic activity and produced maximal activation at 30 mM, whereas other divalent cations, including Mg2+ and Co2+, failed to enhance sulfoconjugation at this concentration. Using the optimized assay condition, the apparent Km for EAY was found to be approximately 1.5 microM, with significant substrate inhibition at EAY concentrations above 2 microM. The 16 amino acid peptide of the C-terminus of C4 possessed an apparent Km of approximately 2.1 microM. Using EAY as a substrate, TPST activity was measured in liver samples from ten organ donors to detect the variability of this enzyme among human subjects. The activity in the male group (1.065 +/- 0.074 pmol/min/mg) was significantly (P less than 0.005) higher than that of the female group (0.662 +/- 0.158 pmol/min/mg), suggesting that TPST activity may be regulated, in part, by sex hormones.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-2952
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
40
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
629-35
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Characterization of a tyrosylprotein sulfotransferase in human liver.
pubmed:affiliation
Department of Pharmacology and Therapeutics, State University of New York School of Medicine and Biomedical Sciences, Buffalo 14214.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.