Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
1990-1-5
pubmed:abstractText
The interaction of dynein with ATP gamma S, a phosphorothioate analogue of ATP, has been investigated in depth. The hydrolyses of ATP gamma S and of ATP were shown to be mutually competitive. ATP gamma S induced complete dissociation of the microtubule-dynein complex such that the time course of dissociation monitored by stopped-flow light-scattering methods followed a single exponential. The ATP gamma S concentration dependence of the rate of dissociation was hyperbolic, indicating that the dissociation is at least a two-step process: M.D + ATP gamma S in equilibrium M.D.ATP gamma S----M + D.ATP gamma S. The fit to the hyperbola gives an apparent Kd = 0.5 mM for the binding of ATP gamma S to the microtubule-dynein complex, and the maximal rate of 45 s-1 defines the rate of dissociation of the ternary M.D.ATP gamma S complex. Rapid quench-flow experiments demonstrated that the hydrolysis of ATP gamma S by dynein exhibited an initial burst of product formation. The size of the burst was 1.2 mol/10(6) g of dynein, comparable to that in the case of ATP hydrolysis. The steady-state rate of ATP gamma S turnover by dynein was activated by MAP-free microtubules. Because the rate of ATP gamma S turnover is severalfold (4-8) slower than ATP turnover, the rate-limiting step must be release of thiophosphate, not ADP. Thus, microtubules can activate the rate of thiophosphate release. The stereochemical course of phosphoric residue transfer was determined by using ATP gamma S stereospecifically labeled in the gamma position with 18O.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7022-7
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Adenosine 5'-O-(3-thiotriphosphate) hydrolysis by dynein.
pubmed:affiliation
Department of Molecular and Cell Biology, Pennsylvania State University, University Park 16802.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't