Alkaline Protease

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Alkaline protease refers to an enzyme that can hydrolyze protein peptide bonds under alkaline conditions, and the optimum pH is in the range of 9-11. It is widely used in detergent, food, medical, brewing, silk, tanning and other industries.

Figure 1. Protein structure of alkaline protease.

Introductions

Alkaline protease, also known as serine protease. There are two common ones, one is Novo protease and the other is Carsberg protease. The properties and structure of the two are similar. They contain 275 and 274 amino acid residues, and are composed of a polypeptide chain. It is stable at pH 6～10, and deactivates quickly when it is lower than 6 or greater than 11. Its active center contains serine, so it is called serine protease. It can not only hydrolyze peptide bonds, but also has the functions of hydrolyzing amide bonds, ester bonds, transesterification and transpeptide. Due to the specificity of enzymes, it can only hydrolyze proteins, not starch, fat and other substances. The appearance is generally powdery, and some are microspheres.

Source

The main source of alkaline protease is microbial extraction. Bacillus is the main source of research and application, and Bacillus subtilis is the most. There are also a small number of other species, such as Streptomyces. The production capacity, enzyme activity, and stability of natural strains often fail to meet the requirements of industrial production. It is necessary to screen and improve strains. Commonly used methods include mutagenesis, genetic engineering, protein engineering, and spore heat treatment. The main goal is to improve enzyme activity, stability (temperature and alkali resistance), anti-oxidation and anti-chelation properties.

Use

Main areas: detergent, tanning, silk, feed, medicine, food, environmental protection, etc.

Its application mainly revolves around its function of hydrolyzing protein peptide bonds. In production and life, there are several main requirements:

• To make complex macromolecular protein structure into simple small molecule peptide chain or amino acid, which becomes easy to absorb or wash Go, such as food, detergent, feed and other fields.
• Partially destroys the protein structure and separates the material components. This is very effective when processing protein-rich materials such as leather and silk.
•  It promotes the degradation of environmental pollutants and is used in the field of environmental protection.
• Protease can both catalyze the hydrolysis reaction. It can also catalyze the reverse reaction, and has a high degree of activity and specificity, which is very suitable for the production needs of certain specific molecules in the pharmaceutical industry.

Applications

• Application of alkaline protease in soybean polypeptide and soybean phospholipid functional food

The soy protein (isolated soy protein or soy protein concentrate, etc.) is hydrolyzed into soy peptides to improve the solubility and functional properties of soy protein. It can be used as a protein supplement and nutritional supplement for beverages, dairy products, and food for the elderly and infants.

• Application of alkaline protease in leather industry

Alkaline protease can be used to make depilatory agent. The tanned leather will be depilated cleanly, with clear grain, no obvious damage, and fine and bright pores.

• Application of alkaline protease in extraction of pharmaceutical raw materials

Alkaline protease can be used for the extraction of heparin and chondroitin sulfate.