Linked Life Data

19470521

Source:http://linkedlifedata.com/resource/pubmed/id/19470521

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2009-8-27
pubmed:abstractText
The interactions of acyl-CoA with medium-chain acyl-CoA dehydrogenases (MCADs) reconstituted with artificial FADs-i.e. 8-CN-, 7,8-Cl(2)-, 8-Cl-, 8-OCH(3)- and 8-NH(2)-FAD-were investigated by UV-visible absorption and FT-IR measurements. Although 8-NH(2)-FAD-MCAD did not oxidize acyl-CoA the wavelength of the absorption maximum of the flavin was altered by acyl-CoAs binding. Thus, 8-NH(2)-FAD-MCAD is one of the attractive materials for investigation of enzyme-substrate (ES) interaction in ES complex (the complex of oxidized MCAD with acyl-CoA). FT-IR difference spectra between non-labelled and [1-(13)C]-labelled acyl-CoA free in solution and bound to oxidized 8-NH(2)-FAD-MCAD were obtained. The broad 1668-cm(-1) band of free octanoyl-CoA assigned to the C(1) = O stretching vibration appeared as a sharp signal at 1626 cm(-1) in the case of the complex. The downward shift indicates a large polarization of C(1) = O, and the sharpness suggests that the orientation of the C(1) = O in the active-site cavity is fairly limited. The hydrogen-bond enthalpy change responsible for the polarization on the transfer of the substrate from aqueous solution to the active site of MCAD was estimated to be approximately 15 kcal/mol. The 1626-cm(-1) band is noticeably weakened in the case of acyl-CoA with acyl chains longer than C12 which are poor substrates for MCAD, suggesting that C(1) = O is likely to exist in multiple orientations in the active-site cavity, whence the band becomes obscured. A band identical to that of bound C8-CoA was observed in the case of C4-CoA which is a poor substrate, indicating the strong hydrogen bond at C(1) = O.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1756-2651
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
146
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
351-7
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
FT-IR spectroscopic studies on the molecular mechanism for substrate specificity/activation of medium-chain acyl-CoA dehydrogenase.
pubmed:affiliation
Department of Physiology, School of Health Sciences, Kumamoto University, Kuhonji, Kumamoto 862-0976, Japan. nishina@kumamoto-u.ac.jp
pubmed:publicationType
Journal Article