Method of extraction
In the 1950s and 1960s, many countries in the world, including China, mainly extracted peptides from animal organs. For example, thymosin injection is prepared by slaughtering a newborn calf, removing its thymus, and then using oscillating separation biotechnology to separate peptides from the calf thymus. This thymosin is widely used to regulate and enhance cellular immune function in humans.
Natural bioactive peptides are widely distributed. There are abundant bioactive peptides in animals, plants and Marine organisms in nature, which play a variety of physiological functions and maintain normal life activities. These natural bioactive peptides include secondary metabolites of organisms such as antibiotics and hormones, as well as bioactive peptides present in various tissue systems.
At present, many bioactive peptides have been isolated from human, animal, plant, microbial and Marine organisms. However, bioactive peptides are generally found in low amounts in organisms, and the current techniques for isolating and purifying bioactive peptides from natural organisms are not perfect, with high cost and low bioactivity.
The commonly used methods for peptide extraction and separation include salting out, ultrafiltration, gel filtration, isoelectric point precipitation, ion exchange chromatography, affinity chromatography, adsorption chromatography, gel electrophoresis, etc. Its main disadvantage is the complexity of operation and high cost.
Acid-base method
Acid and alkali hydrolysis are mostly used in experimental institutions, but are rarely used in production practice. In the process of alkaline hydrolysis of proteins, most amino acids such as serine and threonine are destroyed, racemization occurs, and a large number of nutrients are lost. Therefore, this method is rarely used in production. Acid hydrolysis of proteins does not cause racemization of amino acids, hydrolysis is rapid and the reaction is complete. However, its disadvantages are complex technology, difficult control and serious environmental pollution. The molecular weight distribution of peptides is uneven and unstable, and their physiological functions are difficult to determine.
Enzymatic hydrolysis
Most bioactive peptides are found in long chains of proteins in an inactive state. When hydrolyzed by a specific protease, their active peptide is released from the amino sequence of the protein. Enzymatic extraction of bioactive peptides from animals, plants and Marine organisms has been a research focus in recent decades.
Enzymatic hydrolysis of bioactive peptides is the selection of appropriate proteases, using proteins as substrates and hydrolyzing proteins to obtain a large number of bioactive peptides with various physiological functions. In the production process, temperature, PH value, enzyme concentration, substrate concentration and other factors are closely related to the enzymatic hydrolysis effect of small peptides, and the key is the choice of enzyme. Due to the different enzymes used for enzymatic hydrolysis, the selection and formulation of enzymes, and different protein sources, the resulting peptides vary greatly in mass, molecular weight distribution, and amino acid composition. One usually chooses animal proteases, such as pepsin and trypsin, and plant proteases, such as bromelain and papain. With the development of science and technology and the continuous innovation of biological enzyme technology, more and more enzymes will be discovered and used. Enzymatic hydrolysis has been widely used in the preparation of bioactive peptides due to its mature technology and low investment.
Post time: May-30-2023