An artificial binding protein capable of specifically recognizing allophycocyanin and its obtaining method

Abstract

An artificial binding protein that can specifically recognize allophycocyanin, its amino acid sequence is: HMVDNKFNKEIVNAITEIHHLPNLNLEQRWAFIFSLFDDPSQSANLLAEAKKLNDAQAPKSGGGGSGGGGIGVDNKFNKEWQNAHNEIIWLPNLNWEQKWAFINSLYDDPSQSANLLAEAKKLNDAQAPKAAASDYKDDDDKLEHHH. The protein has the characteristics of strong specificity, high affinity, strong thermal stability, strong acid-base tolerance and the like, and can be applied in the fields of detection and purification of allophycocyanin and the like. In addition, the present invention also relates to a DNA fragment for encoding the above-mentioned artificial binding protein and a method for obtaining the artificial binding protein. In the present invention, by selecting highly stable and highly soluble protein A dimer as the backbone protein, on the basis of it, through processes such as genetic engineering transformation, construction of mutant library, affinity screening, etc., the finally obtained class has antigen binding active protein.

Description

technical field [0001] The invention relates to the technical field of artificial binding proteins, in particular to an artificial binding protein capable of specifically recognizing allophycocyanin and a method for obtaining it. Background technique [0002] Phycobiliprotein is an important light-harvesting pigment protein present in Cyanophyceae, Phodophyceae, Cryptophyceae and a few dinoflagellates (Pyrrophyceae). According to literature records, phycobiliproteins are generally divided into three categories: Phycocyanin (Phycocyanin, referred to as PC, with a maximum absorption peak of 620nm, which is azure blue), phycoerythrin (Phycoerythrin, referred to as PE, with a maximum absorption peak of 562nm, which is purple) red) and Allophycocyanin (APC for short, the maximum absorption peak is 652nm, appearing sky blue). These proteins can not only be used as natural pigments in the fields of food, cosmetics and dyes, but also have special effects on cancer, diabetes, cardio...

AI Technical Summary

Problems solved by technology

However, since the structure of allophycocyanin and phycocyanin is very similar, and it is difficult to completely separate them in the process of antigen preparation and purification, it is difficult to prepare polyclonal antiserum or hybridoma monoclonal antibodies by immunizing animals with traditional antigens. achieve higher specificity

Currently commercial allophycocyanin antibodies are not very specific and have more or less cross-reactivity with phycocyanin

In addition, the antibody molecule itself has a large molecular weight and poor tolerance to acid, alkali and temperature, which greatly limits its application in the detection and purification of antigen molecules.

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