Method for purifying silk fibroin

Abstract

The invention discloses a method for purifying silk fibroin. According to the method, glycerin monostearate sulphate sodium salt, fatty alcohol-polyoxyethylene ether, and sodium diethylhexyl sulfosuccinate are taken as the penetrant. High molecular weight silk fibroin can be obtained through steps of steeping raw silks of silkworm or silkworm cocoon in the penetrant, degumming through weak base and enzyme so as to remove silk glue, then dissolving and dialyzing. The silk fibroin purified by the method does not contain silk glue, less molecular weight of silk fibroin is degraded, the chain H, chain L and P25 of the original silk fibroin can be reserved, the molecular weight of the original silk fibroin is reserved, and the materials such as silk fibroin membranes, fibroin gel, fibroin microsphere, and fibroin porous membranes prepared by the raw material silk fibroin are improved in properties.

Description

technical field [0001] The invention relates to a method for purifying protein, in particular to a method for purifying silk fibroin, and belongs to the technical field of biological materials. Background technique [0002] Silkworm silk is mainly composed of two proteins, silk fibroin and sericin, of which silk accounts for about 70% and sericin accounts for about 30%. Since pure silk fibroin has low antigenicity, while sericin has certain antigenicity, silk fibroin as a biomedical material needs to be purified to remove sericin. Sericin is a protein that constitutes the outer layer of silk fiber, and its protein chain has many amino acids with long side chains, such as arginine, lysine, glutamic acid, methionine, tryptophan, tyrosine etc., and many polar hydrophilic groups (such as hydroxyl, carboxyl, amino, imino, etc.). Sericin is water-soluble and easily soluble in hot water, acid, and alkali solutions, while silk fibroin is only water-swellable and insoluble in water...

AI Technical Summary

Problems solved by technology

In the literature ([J] Journal of Liaocheng Normal University (Natural Science Edition), 1999, 01:43-47+62), it is introduced that boiling water degumming requires high temperature, long time, and degumming is not complete; soap degumming, soap consumption Large, accounting for about 20-30% of raw silk, and the requirements for soap are high, the effect of general soap is not ideal, the degumming ability is weak, the soap used in standard degumming is Marseille soap (a kind of soap prepared from olive oil) , the source is limited, needs to be imported, the price is expensive, and the sericin cannot be completely removed; the literature ([J] Japanese Sericulture Journal, 1955, 1 (6) 32~64) uses the organic acid tartaric acid as the degumming agent, and the degumming condition : The concentration of tartaric acid is 16%, the temperature is 93°C, and the degumming rate is 80% for 2 hours. The degumming rate becomes slower when the degumming time is extended, and tartaric acid is easily absorbed by silk fibroin, and it is difficult to remove. The residual amount is as high as 2.5%, which seriously affects Thereafter, the application of silk fibroin; the degumming method of papain was introduced in the literature ([J]Silk, 2009, 08:20-22)

The condition of enzymatic degumming is relatively mild, but the time is long, the cost is high, and the requirements for emulsifiers are also quite harsh

In the Chinese invention patent with the publication number CN102337599A, a method for degumming silk is disclosed. Put silkworm cocoons into a cloth bag, soak them in water for 16-19 hours, rinse them with clean water, dry them, and put in soda ash with a concentration of 1.8%-2.5%. , heat up to the boiling of the lye, cook for 50-60 minutes, stir while cooking, and rinse with running water until neutral, but this method does not take into account the corrosion effect of the amount of alkali on silk fibroin, so that the obtained silk fibroin The molecular weight is reduced

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