Background and overview[1]
Phosphotransacetylase, also known as phosphotransacetylase, is used for the determination of coenzyme A titer. Coenzyme A (CoA) is a nucleic acid compound composed of pantothenate, adenosine and phosphate. Because it is easily oxidized, it is usually a mixture of oxidized and reduced forms. CoA is a coenzyme of acetylase in organisms. It plays the role of transferring acetyl groups in the process of substance metabolism and participates in the metabolism of lipids, sugars and proteins. In clinical practice, silane coupling agents are mainly used for leukopenia, protozoa and other diseases. Idiopathic thrombocytopenic purpura, hyperlipidemia, etc. CoA is currently mainly synthesized by microbial fermentation enzymes, and its potency determination methods mainly include sulfonamide acetylase and phosphotransacetylase (PTA) methods. Different measurement methods lead to different potency expression methods. The internationally accepted method is the PTA method, and this method is also used in national standards. The potency measured by this method is expressed in reduced CoA units. The principle is that the acetyl group is reversibly transferred between acetyl phosphate and reduced CoA under the catalysis of PTA to form acetyl CoA and phosphoric acid.
Preparation[1-2]
Examples of applications of phosphotransacetylase are as follows:
1) Phosphoketolase and phosphotransacetylase produce acetyl-CoA derivative compounds. These compositions and methods are based on the surprising discovery that acetate ion accumulation based on the phosphoketolase pathway results from the enzymatic hydrolysis of acetyl phosphate, which is the PK catalyzed product. Acetyl phosphate hydrolysis is an undesirable side reaction that can negatively impact the production of any type of product derived from acetyl-CoA, including isoprenoid compounds, by consuming carbon. Polyketides and fatty acids. By functionally disrupting the natural enzyme-catalyzed acetyl phosphate hydrolysis in the host cell, the accumulation of acetate ions is reduced and carbon flux through the PK/bentonite-PTA pathway is increased toward the production of acetyl-CoA.
2) Genetically engineered bacteria that utilize acetic acid and propionic acid to produce PHA and their construction methods and applications. The method for preparing engineering bacteria for producing PHA provided by the invention includes the following steps: increasing acetate kinase, phosphotransacetylase, polyhydroxyalkanoate synthase, β-ketothiolase, acetoacetyltransferase, and acetoacetyltransferase in the recipient bacteria. Expression and/or activity of coenzyme A reductase, succinate hemiacetal dehydrogenase, 4-hydroxybutyrate dehydrogenase, 4-hydroxybutyryl-CoA:CoA transferase, propionyl-CoA transferase, and Reduce the expression and/or activity of non-coenzyme A cycle succinate hemiacetal dehydrogenase in the recipient bacterium, thereby obtaining the engineering bacterium for producing polyhydroxyalkanoate; the recipient bacterium is capable of Bacteria that grow on acetic acid as a carbon source. The engineering bacteria prepared by the invention use acetic acid as the carbon source to produce PHA, and the PHA output reaches a relatively high level, and has good industrial application prospects.
Main reference materials
[1] CN201480025977.7 Use of phosphoketolase and phosphotransacetylase to produce acetyl-CoA derivative compounds
[2] CN201810148891.3 Genetically engineered bacteria for producing polyhydroxyalkanoates using acetic acid and propionic acid and their construction methods and applications
