Alkaline protease is a serine proteolytic enzyme in endopeptidases, which can hydrolyze protein peptide bonds under alkaline conditions, and its optimal pH range is 9-11. It is mainly used in the enzyme detergent industry, and it is also widely used in industries such as tanning, silk, feed, medicine, food, and environmental protection. This enzyme was first found in the pancreas of pigs.
At present, proteolytic enzymes are the most used enzymes in industrial enzymes worldwide, accounting for about 60% of the total enzymes, of which alkaline proteases account for 25%. Its huge application prospects in business and its important role in basic research have attracted many companies and research units to conduct multi-faceted research on it.
There are two common alkaline proteases: one is Novo protease and the other is Carsberg protease. Both have similar properties and structures, containing 275 and 274 amino acid residues, respectively, and are composed of a single polypeptide chain. This enzyme is stable at pH 6-10, and is quickly inactivated at pH below 6 or above 11. It is inactivated when it encounters a reagent that can act on serine-diisopropyl fluorophosphate (DFP).
Alkaline proteases are widely found in bacteria, actinomycetes, and fungi, such as Bacillus licheniformis, Bacillus amyloliquefaciens, Bacillus pumilus, Bacillus alkalophilus, Streptomyces griseus, Streptomyces freundii and certain Fusarium.
The main source of alkaline protease is microbial extraction. Bacillus is the most researched and applied species, but there are also a small number of other species, such as Streptomyces. The enzyme activity and stability contained in the natural strains cannot meet the requirements of industrial production, and the strains need to be screened and improved. Commonly used methods include mutagenesis, genetic engineering, protein engineering, and heat treatment of spores. The main goal is to improve enzyme activity, stability (temperature and alkali resistance), anti-oxidation and anti-chelation properties.
Its application mainly revolves around its function of hydrolyzing protein peptide bonds. There are several main needs in production and life:
- The complex macromolecular protein structure becomes a simple small molecule peptide chain or amino acid, which becomes easy to absorb or wash away. It is mainly used in food, detergent, feed and other fields.
- It partially destroys the protein structure and separates the material components. This is very effective when processing protein-rich materials such as leather and silk.
- Promote the degradation of environmental pollutants and use it in the field of environmental protection.
- Protease can catalyze the hydrolysis reaction and the reverse reaction, and has a high degree of activity and specificity, which makes it very suitable for the production requirements of certain specific molecules in the pharmaceutical industry.
- 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.
- 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.
- Alkaline protease can be used for the extraction of heparin and chondroitin sulfate.