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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1986-5-5
pubmed:abstractText
The rates of ATP synthesis and release by the dynein ATPase were determined in order to estimate thermodynamic parameters according to the pathway: (Formula: see text). Dynein was incubated with high concentrations of ADP and Pi to drive the net synthesis of ATP, and the rate of ATP production was monitored fluorometrically by production of NADPH through a coupled assay using hexokinase and glucose-6-phosphate dehydrogenase. The turnover number for the rate of release of ATP from 22S dynein was 0.01 s-1 per site at pH 7.0, 28 degrees C, assuming a molecular weight of 750 000 per site. The same method gave a rate of ATP synthesis by myosin subfragment 1 of 3.4 X 10(-4) s-1 at pH 7.0, 28 degrees C. The rate of ATP synthesis at the active site was estimated from the time dependence of medium phosphate-water oxygen exchange. Dynein was incubated with ADP and [18O] Pi, and the rate of loss of the labeled oxygen to water was monitored by 31P NMR. A partition coefficient of 0.31 was determined, which is equal to k-2/(k-2 + k3). Assuming k3 = 8 s-1 [Johnson, K.A. (1983) J. Biol. Chem. 258, 13825-13832], k-2 = 3.5 s-1. From the rates of ATP binding and hydrolysis measured previously (Johnson, 1983), the equilibrium constants for ATP binding and hydrolysis could be calculated: K1 = 5 X 10(7) M-1 and K2 = 14.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
25
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
428-34
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Rate of ATP synthesis by dynein.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't