PPK2 protein, and application of PPK2 protein as polyacrylamide gel electrophoresis 35kd standard substance

Abstract

The invention discloses a PPK2 protein, and an application of the PPK2 protein as a polyacrylamide gel electrophoresis 35kd standard substance. A ppk2 gene is inserted into a prokaryotic expression vector pET30a by using NdeI and Hind III, the obtained recombinant expression vector is transferred into an Escherichia coli BL21 (DE3) strain through a physical method, IPTG is used to induce trial expression of the target protein PPK2 at 37 DEG C, 25 DEG C and 16 DEG C, and the obtained expression product is identified and analyzed through SDS-PAGE electrophoresis and Western blotting; and finally, amplification culture is carried out by utilizing 3 L of an expression bacterial liquid, and the expression product is separated and purified through a Ni-IDA affinity chromatographic column, an anion exchange chromatographic column and a gel filtration chromatographic column in sequence. Results show that a large intestine prokaryotic expression system can be stably and efficiently expressed under the induction of the IPTG with the temperature of 16 DEG C and the final concentration of 0.2 mM.L<-1>, and the PPK2 protein has the advantages of specific charged property, existence in a monomerform in a solution, stable properties, non-degradability and long half-life period, and has an application prospect as the polyacrylamide gel electrophoresis 35 kd standard substance.

Description

technical field

[0001] The invention belongs to the technical field of bioengineering, and in particular relates to a PPK2 protein and its application in polyacrylamide gel electrophoresis 35kd standard product. Background technique

[0002] The main function of the protein standard is to indicate the molecular weight of the protein band on the polyacrylamide gel electrophoresis of the protein. It is a positive control. Only when the standard is accurate can the experimental results be convincing. In addition, protein standards can also indicate the success of membrane transfer during Western blot or the degree of electrophoresis of proteins on the gel, so choosing the correct protein standard is one of the necessary conditions for the success of molecular biology experiments.

[0003] Polyphosphate kinase 2 (Polyphosphate kinase 2, PPK2) plays an important role in the pathogenicity of many pathogenic bacteria, but no ppk2 gene has been found in humans and other metazoans, s...

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