In enzymology, an enoyl-[acyl-carrier-protein] reductase (NADPH, B-specific) (EC 1.3.1.10) is an enzyme that catalyzes the chemical reaction

acyl-[acyl-carrier-protein] + NADP⁺ ${\displaystyle \rightleftharpoons }$ trans-2,3-dehydroacyl-[acyl-carrier-protein] + NADPH + H⁺

Thus, the two substrates of this enzyme are [[acyl-[acyl-carrier-protein]]] and NADP⁺, whereas its 3 products are [[trans-2,3-dehydroacyl-[acyl-carrier-protein]]], NADPH, and H⁺.

This enzyme belongs to the family of oxidoreductases, to be specific, those acting on the CH-CH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is acyl-[acyl-carrier-protein]:NADP+ oxidoreductase (B-specific). Other names in common use include acyl-ACP dehydrogenase, reductase, enoyl-[acyl carrier protein] (reduced nicotinamide, adenine dinucleotide phosphate), NADPH 2-enoyl Co A reductase, enoyl acyl-carrier-protein reductase, enoyl-ACP reductase, and enoyl-[acyl-carrier-protein] reductase (NADPH, B-specific). This enzyme participates in fatty acid biosynthesis.

As of late 2007, two structures have been solved for this class of enzymes, with PDB accession codes 1ULU and 2YW9.

• Saito K, Kawaguchi A, Okuda S, Seyama Y, Yamakawa T (1980). "Incorporation of hydrogen atoms from deuterated water and stereospecifically deuterium-labeled nicotin amide nucleotides into fatty acids with the Escherichia coli fatty acid synthetase system". Biochim. Biophys. Acta. 618 (2): 202–13. doi:10.1016/0005-2760(80)90026-0. PMID 6990992.
• Seyama Y, Kasama T, Yamakawa T, Kawaguchi A, Saito K (November 1977). "Origin of hydrogen atoms in the fatty acids synthesized with yeast fatty acid synthetase". J. Biochem. 82 (5). Tokyo: 1325–9. doi:10.1093/oxfordjournals.jbchem.a131820. PMID 338601.
• Weeks G, Wakil SJ (1968). "Studies on the mechanism of fatty acid synthesis. 18. Preparation and general properties of the enoyl acyl carrier protein reductases from Escherichia coli". J. Biol. Chem. 243 (6): 1180–9. PMID 4384650.