Acyl carrier protein (ACP) inhibition and other differences between beta-ketoacyl synthase (KAS) I and II.
Escherichia coli beta-ketoacyl synthases (KAS) I and II carry out the elongation steps in fatty acid synthesis. Analyses using the cross-linker BS(3) [bis(sulphosuccinimidyl) suberate] and surface-enhanced laser desorption/ionization-time-of-flight MS disclosed only monomeric and dimeric forms of KAS II, whereas KAS I also forms higher multimers. The binding affinities for KAS I and KAS II to C(14)-acyl carrier protein (ACP) as well as for C(14)-ACP to KAS I and KAS II were determined. KAS I is sensitive to the ACP released during the transfer reaction, with 50% inhibition at 0.17 microM ACP close to the physiological concentration of ACP (0.13 microM). KAS I and II also differ in carrying out the decarboxylation step of the elongation reaction.
Arnvig Mcguire
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Genetics Department, Molecular Biology Institute, Copenhagen University, Oester Farimagsgade 2A, DK-1353 Copenhagen K, Denmark.
McGuire
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JN
von Wettstein-Knowles
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P
D015099:3-Oxoacyl-(Acyl-Carrier-Protein) Synthase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D000213:Acyl Carrier Protein / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004926:Escherichia coli / Q000201:enzymology; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D019814:Myristic Acid / Q000378:metabolism; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013388:Succinimides / Q000494:pharmacology
D000213:Acyl Carrier Protein; D003432:Cross-Linking Reagents; D007527:Isoenzymes; D011994:Recombinant Proteins; D013388:Succinimides; D019814:Myristic Acid; C035760:bis(sulfosuccinimidyl)suberate; C078182:beta-ketoacyl-acyl carrier protein synthase I; D015099:3-Oxoacyl-(Acyl-Carrier-Protein) Synthase