Linked Life Data

1727643

Source:http://linkedlifedata.com/resource/pubmed/id/1727643

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1992-1-23
pubmed:abstractText
Soybean (Glycine max (L.) Merr.) root nodules contain the enzymes of the ascorbate-glutathione cycle as an important defense against activated forms of oxygen. A key enzyme in this cycle--monodehydroascorbate reductase (MR)--was purified 646-fold and appeared as a single band on SDS-PAGE with silver or Coomassie blue staining. Purified MR contained 0.7 mol FAD/mol enzyme and had a specific activity of 288 mumol NADH oxidized.min-1.mg protein-1. The enzyme was a single subunit occurring as two isozymes (MR I and MR II) with Mr values of 39,000 and 40,000. Isoelectric focusing revealed that each isozyme consisted of two forms with pl values of 4.6 to 4.7. Ferricyanide and 2,6-dichlorophenol-indophenol were effective as electron acceptors. The purified enzyme did not possess leghemoglobin reductase activity. Inhibition by p-chloromercuribenzoate indicated the involvement of a thiol group in MR activity. The Km values were 5.6, 150, and 7 microM for NADH, NADPH, and monodehydroascorbate, respectively. The pH optimum was 8 to 9. The N-terminal sequence of 10 amino acids of MR II had little homology to known protein sequences.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0003-9861
pubmed:author
pubmed:issnType
Print
pubmed:volume
292
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
281-6
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Purification and characterization of monodehydroascorbate reductase from soybean root nodules.
pubmed:affiliation
Department of Biology, Reed College, Portland, Oregon 97202.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't