Linked Life Data

2841330

Source:http://linkedlifedata.com/resource/pubmed/id/2841330

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
24
pubmed:dateCreated
1988-9-20
pubmed:abstractText
Calcium-activated neutral proteases (calpain, EC 3.4.22.17) bind to agarose matrices (Bio-Gel A-150m, Sepharose 4B, and Ultrogel AcA 34) with high affinity in the presence of calcium. 6-O-beta-Galactopyranosyl-D-galactose, a disaccharide which closely resembles the repeating unit of the agarose matrices, completely blocks the binding of calpains and can release agarose-bound enzymes in the presence of calcium. At least 1 microM level of free calcium is required for binding. Other calcium binding proteins, including calmodulin, calpastatin, casein, and neurofilament proteins, fail to bind under the same conditions. Both calpain I and calpain II can be readily purified from crude enzyme preparations by agarose chromatography in the presence of calcium and leupeptin. Agarose-bound enzymes are eluted with calcium-free solutions or can be released in the presence of calcium by 1% Triton X-100, but not by 1 M urea or 20% ethylene glycol. Enzymes eluted from agarose are activated, as evidenced by the appearance of faster migrating forms (76 and 78 kDa) of the 80-kDa catalytic subunit of calpain I upon electrophoresis and by the increased sensitivity of calpain II to activation by micromolar levels of calcium. The electrophoretic migration of the 30-kDa regulatory subunit is, however, unaltered in enzyme fractions eluted from an agarose column. When the enzyme subunits are dissociated in 1 M NaSCN, only the 30-kDa subunit binds to the agarose matrix. Furthermore, neither calpain I nor calpain II binds to agarose when their 30-kDa subunit is autocatalyzed to an 18-kDa fragment, indicating that the NH2-terminal of the 30-kDa subunit is important for the binding of calpains to an agarose matrix.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Calcium, http://linkedlifedata.com/resource/pubmed/chemical/Calcium-Binding Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Calpain, http://linkedlifedata.com/resource/pubmed/chemical/Disaccharides, http://linkedlifedata.com/resource/pubmed/chemical/Ethylene Glycol, http://linkedlifedata.com/resource/pubmed/chemical/Ethylene Glycols, http://linkedlifedata.com/resource/pubmed/chemical/Leupeptins, http://linkedlifedata.com/resource/pubmed/chemical/Octoxynol, http://linkedlifedata.com/resource/pubmed/chemical/Polyethylene Glycols, http://linkedlifedata.com/resource/pubmed/chemical/Sepharose, http://linkedlifedata.com/resource/pubmed/chemical/Thiocyanates, http://linkedlifedata.com/resource/pubmed/chemical/Urea, http://linkedlifedata.com/resource/pubmed/chemical/calpastatin, http://linkedlifedata.com/resource/pubmed/chemical/leupeptin, http://linkedlifedata.com/resource/pubmed/chemical/sodium thiocyanate
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
263
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11609-12
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Calcium-activated neutral proteases (calpains) are carbohydrate binding proteins.
pubmed:affiliation
Department of Pathology and Laboratory Medicine, University of Pennsylvania Medical School, Philadelphia 19104.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.