Preparation method of selenium-containing protein in selenium-enriched yeast

Abstract

The invention discloses a preparation method of a selenium-containing protein in a selenium-enriched yeast, which mainly comprises the following steps: (1) performing high-pressure homogenizing and crushing on a selenium-enriched yeast, and then centrifuging; (2) adding 75-90% (percentage by mass) of ammonium sulfate into the centrifuged supernatant, stirring, then centrifuging to collect precipitate, dissolving the precipitate in a buffer solution, dialyzing a dialysis bag, performing dewatering concentration with polyethyleneglycol to a smaller volume, and performing vacuum freeze-drying to obtain a crude protein; and (3) dissolving a little dry crude protein powder in a Tris-HCl buffer solution, passing through a 0.22 mu m microporous filtering film, then loading onto a Sephadex column, eluting under the conditions that the flow rate is 0.5-3 ml / min, the detection wavelength is 280 nm and the eluate is a 50-150 mmol / L Tris-HCl buffer solution, and collecting a protein component. Compared with the prior art, the preparation method achieves the advantages of high crushing ratio, sufficient crude protein extraction, high selenium content in the purified protein and high purity of the targeted selenium-containing protein.

Description

technical field [0001] The invention relates to a preparation method of selenoprotein in selenium-enriched yeast. Background technique [0002] Selenium is an essential trace element for humans and animals, and a component of glutathione peroxidase (GSH-Px). Selenium also has a variety of biological functions, such as anti-oxidation, anti-cancer, anti-aging, improving human immunity, and protecting cardiovascular and cerebrovascular functions. Its biological functions are mainly expressed by selenoproteins. Most of the selenoproteins that have been discovered are enzymes with important functions, also known as selenoenzymes. At present, a large number of studies have shown that more than 40 diseases of the human body, such as Keshan disease, goiter, arthritis, diabetes, cataract, cancer, etc., are closely related to the nutritional status of selenium. Therefore, the research on selenoproteins has become an important topic in recent years. hot research topics. For example,...

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Problems solved by technology

For example, Chen Hanjie et al. extracted selenoproteins from yeast through repeated freezing and thawing (Chen Hanjie et al. Chromatographic separation and analysis of selenoproteins in selenium yeast. Journal of Jinan University, 1993, 14 (1): 60-62.), Laure et al. used Selenoproteins were extracted after ultrasonically disrupting yeast cells (Laure et al. Identification of selenium-containing proteins in selenium-rich yeast aqueous extract by 2D gel lectrophoresis, nanoHPLC–ICPMS and nanoHPLC–ESI MS / MS, Talanta, 2008,75:1140 -1145.), etc., the existing preparation methods of selenoproteins in selenium-enriched yeast usually use ultrasound, acid extraction or repeated freezing and thawing to break the yeast cells and then extract selenoproteins, but because of the thickness of the yeast cell wall, the ultrasonic disruption efficiency is not high. Proteins are easily inactivated after chemical extraction, and less protein is purified in the later stage, which greatly limits the application of selenoproteins