Linked Life Data

6311982

Source:http://linkedlifedata.com/resource/pubmed/id/6311982

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1983-11-23
pubmed:abstractText
Synaptosomal plasma membranes (SPMs) were prepared from whole rat brain and assayed for calcium-stimulated proteolytic activity. Addition of calcium to SPMs caused a dose-dependent increase in trichloroacetic acid-soluble protein. Two peaks of protease activity directed against a casein substrate were detectable when SPMs were incubated with low-ionic-strength buffer and the extract was fractionated on DEAE-cellulose. The enzyme in peak 1 required less than 1/10 the calcium concentration for activation as the peak 2 protease (Kact1 = 35 microM; Kact2 = 500 microM). The specific thiol-protease inhibitors leupeptin and antipain and the alkylator iodoacetate blocked enzyme activity. The low-sensitivity protease was converted to a high-sensitivity enzyme (Kact = 20 microM) by substrate affinity chromatography in the presence of calcium. This protease was purified 550-fold from SPMs. The high- and low-sensitivity membrane-associated calcium-dependent proteases are part of a family of enzymes, the calpains, previously reported in cytosolic fractions of several tissues.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0022-3042
pubmed:author
pubmed:issnType
Print
pubmed:volume
41
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
950-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
Purification from synaptosomal plasma membranes of calpain I, a thiol protease activated by micromolar calcium concentrations.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.