ApcE2 protein mutant and application thereof

Abstract

The present invention discloses a wild type ApcE2 protein mutant. The mutant is characterized by being obtained by mutation of at least one amino acid in an amino acid sequence shown in a SEQ ID No.1,and wherein the amino acid mutation is selected from at least one of mutation of a amino acid site outside a loop, mutation of an amino acid site inside a loop, and a loop structure sequence with partial deletion mutation. The ApcE2 protein mutant of the present invention has a higher solubility than that before the mutation, and the unit yield expressed in Escherichia coli is remarkably improved. The ApcE2 protein mutant of the invention can be used for fluorescence labeling tissue localization, preparation and extraction of phytochrome P[phi]B, preparation of other phycobiliproteins, such as phycoerythrin PEB and phycocyanobilin PCB, and in vitro recombination of fluorescent phycobiliprotein. The preparation method of the present invention realizes higher unit yield and better solubility of the pigment protein.

Description

technical field [0001] The present invention relates to ApcE2 protein mutants and applications thereof. Background technique [0002] The development of modern biology has increasingly relied on optical techniques, such as fluorescence imaging, optical detection, and light-induced manipulation. For imaging and positioning of deep tissue in vivo, it is best to use fluorescence in the 650nm-900nm band. Because the light in this band has less autofluorescence, less light scattering and less tissue damage. In recent years, two types of proteins that have been studied more as fluorescent probes are the green fluorescent protein family and the bacterial phytochrome protein (BphP). [0003] In order to better adapt to the environment and capture more energy from the environment, a few cyanobacteria have slowly evolved phycobilisomes that can utilize far-red light. In these phycobilisomes, there are usually one to three allophycocyanin subunits different from the traditional nucl...

AI Technical Summary

Problems solved by technology

[0005]Because ApcE2 is a membrane protein, it needs to be dissolved under the condition of high concentration of denaturant (3.5mol / L urea); it is not stable enough at room temperature, so it will affect the labeling

Existing literature (Miao Dan. Research and Molecular Evolution of Red-shifted Phycobiliproteins and Phytochromes [D]. 2017.) reported: truncation of the N-terminal and C-terminal of the protein and partial deletion of the loop (77-161) , did not increase protein solubility

Images