Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
33
pubmed:dateCreated
1986-12-24
pubmed:abstractText
Subunit III was removed from beef heart cytochrome oxidase by incubation of the isolated enzyme at 25 degrees C for 24 h in lauryl maltoside buffer at a detergent to protein ratio of 10:1 (w:w). During the course of the incubation, the reaction of the enzyme with cyanide was followed by spectrophotometry in the Soret region. The starting material binds cyanide in a multiexponential process with 70% of the reaction occurring during the slow phase of the reaction at an observed rate of 3.85 X 10(-5) S-1 with 1 mM KCN. More of the enzyme binds cyanide during the fast phase of the reaction at an observed rate of 3.8 X 10(-3) S-1 as subunit III is removed by lauryl maltoside. After 24 h of incubation in lauryl maltoside, the enzyme reacts with cyanide completely in a rapid, single exponential process. When the protein from such an incubation is recovered by cytochrome c affinity chromatography and analyzed for its subunit content, subunit III is absent. The position of the Soret maximum of the oxidized enzyme shifts from its maximum at 418 nm in the starting material to 422 nm in the subunit III-depleted enzyme. The subunit III-depleted enzyme binds cyanide completely in a simple bimolecular reaction with a rate constant of 3.8 M-1 S-1. We discuss this result in terms of the possible structural and functional roles for subunit III in the cytochrome oxidase complex.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
261
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
15356-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Cyanide binding to bovine heart cytochrome c oxidase depleted of subunit III by treatment with lauryl maltoside.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.