Palmitoleate formation by soybean stearoyl-acyl carrier protein desaturase.
Palmitoyl (hexadecanoyl)-acyl carrier protein (ACP) was found to be an alternate substrate for recombinant soybean stearoyl (octadecanoyl)-ACP delta 9-desaturase. The fatty acid product was identified as palmitoleic acid ((Z)-hexadec-9-enoic acid), which suggests that the locus of desaturation was fixed with respect to the carboxyl, not methyl, end of each substrate acyl group. The apparent specificity factor (Vmax/Km) of the desaturase for stearoyl-ACP was > 100-fold larger than for palmitoyl-ACP, mostly because of the difference in Vmax for the two substrates.
Gibson
K J
KJ
Central Research and Development Department, E.I. DuPont de Nemours, Wilmington, DE 19880-0402, USA.
D000213:Acyl Carrier Protein / Q000378:metabolism; D001665:Binding Sites; D002250:Carbon Radioisotopes; D005229:Fatty Acids, Monounsaturated / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D013025:Glycine max / Q000201:enzymology*
D000213:Acyl Carrier Protein; D002250:Carbon Radioisotopes; D005229:Fatty Acids, Monounsaturated; C008757:palmitoleic acid; D006899:Mixed Function Oxygenases; C018747:acyl-(acyl-carrier-protein)desaturase