20406-62-6Relevant articles and documents
MICROORGANISMS FOR PRODUCING 4C-5C COMPOUNDS WITH UNSATURATION AND METHODS RELATED THERETO
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Paragraph 0015; 00101, (2016/01/25)
The invention provides a non-naturally occurring microbial organism having a butadiene, crotyl alcohol, 2,4-pentadienoate, 3-buten-2-ol, or 3-buten-1-ol, pathway. The microbial organism contains at least one exogenous nucleic acid encoding an enzyme in a pathway. The invention additionally provides a method for producing butadiene, crotyl alcohol, 2,4-pentadienoate, 3-buten-2-ol, or 3-buten-1-ol,. The method can include culturing a butadiene, crotyl alcohol, 2,4-pentadienoate, 3-buten-2-ol, or 3-buten-1-ol-producing microbial organism, where the microbial organism expresses at least one exogenous nucleic acid encoding a pathway enzyme in a sufficient amount, and under conditions and for a sufficient period of time to produce butadiene, crotyl alcohol, 2,4-pentadienoate, 3-buten-2-ol, or 3-buten-1-ol.
The contribution of the substrate's carboxylate group to the mechanism of 4-oxalocrotonate tautomerase
Lian, Huiling,Czerwinski, Robert M.,Stanley, Thanuja M.,Johnson Jr., William H.,Watson, Robert J.,Whitman, Christian P.
, p. 141 - 156 (2007/10/03)
4-Oxalocrotonate tautomerase (4-OT) converts 2-oxo-4E-hexenedioate (1) to 2-oxo-3E-hexenedioate (3) through the dienol intermediate, 2-hydroxy-2,4- hexadiene-1,6-dioate (2). Previous studies established that the isomerization of 1 to 3 is primarily a suprafacial process. It was also suggested that the 6-carboxylate group of the substrate maintains the regio- and stereochemical fidelity of the reaction by anchoring the substrate at the active site. A subsequent study suggested an additional role for the 6-carboxylate group in the mechanism: the enzyme may utilize the binding energy of the carboxylate group to facilitate catalysis. In order to explore the role of the carboxylate group in the mechanism further, the nonenzymatic ratee constants for mono- and dicarboxylated substrates were measured and compared to the rates obtained for the corresponding enzymatic reactions. The results show that the missing carboxylate group has a profound effect on enzymatic catalysis as evidenced by the significant decreases (a 104- and a 105-fold reduction) in the values of k(cat)/K(m) observed for the two monocarboxylated substrates. A comparison of the noneeenzymatic rate constants indicates that the reduced k(cat)/K(m) values cannot be explained on the basis of the chemical reactivities. The stereochemical course of the 4-OT-catalyzed reaction was also determined using 2-hydroxy-2,4Z-heptadiene-1,7-dioate. The stereochemical analysis reveals that the presence of the carboxylate group improves the stereoselectivity of the enzyme-catalyzed ketonization of 2- hydroxy-2,4Z-heptadiene-1,7-dioate to 2-oxo-[3-2H]-4Z-heptene-1,7-dioate in 2H2O - a result that is consistent with its previously assignned role. These findings provide further evidence that the substrate's carboxylate group contributes to the mechanism of the enzyme in two ways: it anchors the substrate at the active site and it facilitates catalysis by destabilizing the substrate or by stabilizing the transition state.
Dehalogenation and Deamination of L-2-Amino-4-chloro-4-pentenoic Acid by Proteus mirabilis
Moriguchi, Mitsuaki,Hoshino, Seiichi,Hatanaka, Shin-Ichi
, p. 3295 - 3300 (2007/10/02)
Eighty-one strains of bacteria were tested for their ability to catalyze the release of chloride ion from DL-2-amino-4-chloro-4-pentenoic acid.A dehalogenating enzyme was obtained from the cells of Proteus mirablis IFO 3849, which can use the L-isomer.The enzyme was constitutively produced.The conversion of L-2-amino-4-chloro-4-pentenoic acid to 2-keto-4-pentenoic acid, ammonia, and chloride ion was demonstrated.The reaction product, 2-keto-4-pentenoic acid, was isolated as its 2,4-dinitrophenylhydrazone and identified by catalytic hydrogenolysis of the hydrazone to the corresponding amino acid, norvaline.
