Asian Science Citation Index is committed to provide an authoritative, trusted and significant information by the coverage of the most important and influential journals to meet the needs of the global scientific community.  
ASCI Database
308-Lasani Town,
Sargodha Road,
Faisalabad, Pakistan
Fax: +92-41-8815544
Contact Via Web
Suggest a Journal
Articles by R Miura
Total Records ( 1 ) for R Miura
  Y Nishina , K Sato , H Tamaoki , C Setoyama , R Miura and K. Shiga

The interactions of acyl-CoA with medium-chain acyl-CoA dehydrogenases (MCADs) reconstituted with artificial FADs—i.e. 8-CN-, 7,8-Cl2-, 8-Cl-, 8-OCH3- and 8-NH2-FAD—were investigated by UV-visible absorption and FT-IR measurements. Although 8-NH2-FAD-MCAD did not oxidize acyl-CoA the wavelength of the absorption maximum of the flavin was altered by acyl-CoAs binding. Thus, 8-NH2-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 [1-13C]-labelled acyl-CoA free in solution and bound to oxidized 8-NH2-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 ~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.

Copyright   |   Desclaimer   |    Privacy Policy   |   Browsers   |   Accessibility