Dissertation > Industrial Technology > Chemical Industry > Other chemical industries > Protein ( PrP ) and the chemical processing industry > Chemical processing > Proteolysis and intermediates > Polypeptide

Purification of the Main Ingredients of the Waste Silk and Investigation of Preparation of Cholesterol Peptides from Silk Fibroin by Enzymatic

Author LanJianJing
Tutor LiaoDanKui
School Guangxi University
Course Chemical processes
Keywords Silk fibroin hypocholesterolemic activity Inhibitory ratio Alkaline protease controllable-hydrolysis kinetic model
CLC TQ936.16
Type Master's thesis
Year 2013
Downloads 32
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Silk fibroin is a kind of high-quality albumen source. It is a kind of high-quality albumen source. Enzymatic hydrolysis of protein is a kind of biochemical process to yield small molecular products such as peptones and peptides. Silk fibroin and alkaline proteinase were chosen as substrate and enzyme, respectively.The concrete research content is as follows:By comparing the solubility of fibroin in the solution of magnesium chloride, calcium chloride and zinc chloride, we found that calcium chloride is the best solvent for dissolving fibroin. The optimum conditions for dissolving fibroin are shown as below:optimum concentration of40%, the optimum temperature was90℃; the best bath ratio of1:50(m/v), pH effect of the solution may be ignored.Comparing with the dialysis method, acid chromatography and freezing method of the effect of extracting sericin, we find freezing method is the best way to extract sericin.The best extraction conditions is:pH=4,-20℃,13h. the liquid density of sericin for32.8%.This paper researched on the inhibitory activity of silk peptides against the solubility of cholesterol in the bile colloid solution. The silk peptides could be obtained from soluble silk fibroin by enzymatic hydrolysis. The hydrolysis degree can reach16.5%and its hydrolyzates have most activity. Alkali proteinase is shown to be the most suitable one. The optimum conditions of alkali protease hydrolysis were determined that the amount of production20g/L, the amount of enzyme0.4g/L, at temperature of40℃and pH9.5.Based on the experimental data and empirical formula, the kinetic model about hydrolyzing of Silk fibroin by alkaline proteinase was deduced respectively. And the results of general kinetic equation for this hydrolysis process were suggested:r=(9.3529Eo+0.3444S0)exp[-0.2417(DH)], DH=4.1382In[1-(0.2601E0/S0+0.0832)t]. At the same time for the accuracy of the models was tested, the results showed that In a certain range of can characterization of alkali protease-silk grain protein reaction rule.

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