Linked Life Data

9657680

Source:http://linkedlifedata.com/resource/pubmed/id/9657680

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
27
pubmed:dateCreated
1998-7-30
pubmed:abstractText
We have separately expressed the Dictyosteliumdiscoideum myosin II nonhydrolyzer point mutations E459V and E476K [Ruppel, K. M., and Spudich, J. A. (1996) Mol. Biol. Cell 7, 1123-1136] in the soluble myosin head fragment M761-1R [Anson et al. (1996) EMBO J. 15, 6069-6074] and performed transient kinetic analyses to characterize the ATPase cycles of the mutant proteins. While the mutations cause some changes in mantATP [2'(3')-O-(N-methylanthraniloyl)-ATP] and mantADP binding, the most dramatic effect is on the hydrolysis step of the ATPase cycle, which is reduced by 4 (E476K) and 6 (E459V) orders of magnitude. Thus, both mutant myosin constructs do in fact catalyze ATP hydrolysis but have very long-lived myosin.ATP states. The E459V mutation allowed for a direct measurement of the ATP off rate constant from myosin, which was found to be 2 x 10(-)5 s-1. Actin accelerated ATP release from this E459V construct by at least 100-fold. Additionally, we found that the affinity of the E476K construct for actin is significantly weaker than for the wild-type construct, while the E459V mutant interacts with actin normally. Their functional properties and the fact that they can be produced and purified in large amounts make the E476K and E459V constructs ideal tools to elucidate key structural features of the myosin ATPase cycle. These constructs should allow us to address important questions, including how binding of ATP to myosin heads results in a >3 order of magnitude reduction in actin affinity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
37
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9679-87
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Kinetic characterization of myosin head fragments with long-lived myosin.ATP states.
pubmed:affiliation
Department of Biochemistry, Stanford University, California 94305, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.