![]() ![]() ![]() The report of the subcommittee was received by CBN in 1972 and circulated widely among experts in the field. In view of the rapid development in the field, particularly of conjugated or derived forms of enzymes as related to enzyme regulation, a new subcommittee was appointed to unify the nomenclature of covalently modified enzymes. These were later revised by a sub-committee of the IUPAC-IUB Commission on Biochemical Nomenclature (CBN) and the revised recommendations were published in 1971 ( 2). Recommendations on the nomenclature of multiple forms of enzymes were prepared by a subcommittee appointed by the International Union of Biochemistry and published in 1964 in a number of journals ( 1). Nomenclature of Enzymes with Proteolytic or other Irreversible Modifications ![]() Nomenclature of Genetically Variant Enzymes (Allelozymes) Wieland, for drafting these recommendations.Īny comments should be sent to any member of the Committee If you need to cite these rules please quote these references as their source.ĬBN thanks a subcommittee on Nomenclature of Interconvertible Enzymes whose members were E H Fischer, E. Mile End Road, London, E1 4NS, Rules are as close as possible to the published version. School of Physical and Chemical Sciences, Queen Mary University of London, Nomenclature of Multiple Forms of Enzymes Recommendations 1976 Our study provides a new possibility for the industrial production of enzymatic synthesis of pyrrolidone.īiocatalysis carnitine CoA ligase protein engineering pyrrolidone.Multiple forms of Enzymes IUPAC-IUB Commission on Biochemical Nomenclature (CBN) Finally, we efficiently produced pyrrolidone by one pot in vivo with 95.2% conversion and 0.69 g/L/h productivity. The catalytic efficiency of carnitine CoA ligase from Escherichia coli ( EcCaiC) was improved by mechanism-based protein engineering, and the titer of pyrrolidone was further increased by ribosome-binding site (RBS), induction conditions, and conversion conditions optimization. ![]() IMPORTANCE This study developed a three-enzyme cascade pathway for the production of pyrrolidone from l-Glu. Our findings demonstrate a strategy that is potentially attractive for the industrial production of pyrrolidone. Finally, under optimal induction and transformation conditions, 16.62 g/L of pyrrolidone was generated from 30 g/L l-Glu (batch feeding) within 24 h with a molar conversion rate of 95.2% and the highest productivity ever obtained, to our knowledge (0.69 g/L/h). Furthermore, ribosome-binding site (RBS) optimization led to an increase in the expression level of EcCaiC F380M/N430D, which was then cloned into the plasmid pET- EcCaiC F380M/N430D- DegoPPK2. For this, we (i) eliminated the steric hindrance of the loop ring to improve the precatalytic conformation of the adenylation intermediate and (ii) fixed the hinge region to stabilize the closed conformation of the enzyme. Here, we obtained the best EcCaiC F380M/N430D double mutant with a k cat/ K m value 1.5 times higher than that of the wild type via mechanism-based protein engineering. The carnitine-CoA ligase from Escherichia coli ( EcCaiC) at a low expression level and with a low activity is regarded as the rate-limiting enzyme. Here, we developed and reconstructed a three-enzyme cascade pathway using Escherichia coli BL21(DE3) for the production of pyrrolidone from l-glutamate (l-Glu). However, the efficient enzymatic synthesis of pyrrolidone remains a challenge. Pyrrolidone is a high value-added monomer and an important active drug intermediate. ![]()
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