Freeze-drying protective agent for protease K as well as preparation method and application of freeze-drying protective agent

Abstract

The invention provides a freeze-drying protective agent for protease K as well as preparation method and application of the freeze-drying protective agent. The freeze-drying protective agent comprises 0.1 to 0.4 w/v% of beta-alanine, 0.2 to 0.5 w/v% of sucrose, 0.1 to 0.4 w/v% of trehalose, 0.05 to 0.2 w/v% of PVP, 0.05 to 0.2 w/v% of albumin, 0.1 to 0.5 w/v% of mannitol, 0.04 to 0.2 w/v% of sorbitol, 0.05 to 0.2 w/v% of polysaccharides, 0.01 to 0.1 v/v% of Tween-80, 0.5 to 1 v/v% of tertiary butanol and the balance of ultrapure water, and addition mass ratios of the sucrose to the trehalose and the mannitol to the sorbitol are (1-2): 1 and (2-4): 1. A proteinase K freeze-dried powder containing about 30% of the freeze-drying protective agent of the invention has a specific activity of more than 30 U/mg, can be stored at 4 DEG C for more than 2 years, and can maintain stable specific activity when heated at 37 DEG C for 3 months.

Description

technical field [0001] The invention belongs to the technical field of enzyme preservation, and more specifically relates to a freeze-drying protectant for proteinase K, its preparation method and application. Background technique [0002] Proteinase K is a serine protease that was first discovered in 1974. Proteinase K has a broad-spectrum cleavage ability to natural proteins, preferring to cleave aliphatic amino acids and aromatic amino acids, especially the carboxy-terminal peptide bond of alanine. [0003] Proteinase K has high activity at high temperature (65°C) and a wide pH range (7.5-12.0), and can react with denaturants and detergents (such as urea, SDS, guanidine hydrochloride, guanidine isothiocyanate, Triton Compatible with Tween, etc., and within a certain concentration range, these denaturants and detergents can improve the activity of proteinase K; the above characteristics make proteinase K a good application in the field of biotechnology that requires non-s...

AI Technical Summary

Problems solved by technology

[0006] In the prior art, the solid content of proteinase K in the freeze-dried proteinase K powder is generally low, which cannot meet the needs of high-end reagent manufacturers; in addition, since the specific activity of proteinase K in general liquid proteinase K is about 40 U / mg, proteinase K in freeze-dried Part of the enzyme activity is lost during the process. If the solid content of proteinase K is low, it will be difficult to achieve a dry powder specific activity of more than 30U / mg

Images