Research On Extraction,Activity And Stability Of Immunoglobulin G By ?/?-Galactosidase-Assisted Saturated Ammonium Sulfate Method(from Yak Blood)

In this study,Gansu GanNan fresh yak blood as the research object,The single factor analysis method was used to analyze the activity and stability of blood IgG in yak,The extracting process of IgG were optimized by using single factor and response surface analysis method.The samples were analyzed.The main findings are as follows:1.The optimum process parameters of extraction of IgG by ?-galactosidase-assisted saturated ammonium sulfate method were obtained as Hydrolysis time 2 h,enzymatic pH 4.4,hydrolysis temperature of 39 ?,enzyme dosage 5 m L(467.5 U),the optimal concentration of IgG was 27.13 mg/mL conserved enzyme treatment the content of IgG was 22.35 mg/mL improve 21.28%(P<0.05).2.The optimum process parameters of extraction of IgG by ?-galactosidase-assisted saturated ammonium sulfate method were obtained as Hydrolysis time 4 h,enzymatic pH 5.5,hydrolysis temperature of 40 ?,enzyme dosage 3.1 m L(467.5 U),the optimal concentration of IgG was 27.51 mg/mL conserved enzyme treatment the content of IgG was 22.35 mg/mL improve 23.09%(P<0.05).3.After enzyme treatment,the activated content of IgG was 15.92 mg/mL,conserved?-galactosidase enzyme processing activated content of IgG was 16.07 mg/mL decreased by0.93% by ELISA.the activated content of IgG was 15.71 mg/mL,conserved ?-galactosidase enzyme processing activated content of IgG was 16.07 mg/mL decreased by 2.24% by ELISA(p>0.05).4.IgG in the acid and heating environment,IgG becomes unstable,enzyme treatment,IgG stability loss is higher than no enzyme treatment,but the difference is not very significant,65 ? above,the loss rate of IgG more than 10%,pH?3.0,the IgG loss rate of more than20%,pH?10.0,the IgG loss of more than 10%.5.Sucrose,glycine and sorbitol have a good protective effect on the activity of IgG in acid and alkali environment.With the increase of the concentration of protective agent,the protective effect is also increased.6.Fourier transform infrared spectroscopy(FTIR)was used to analyze the non-enzyme samples and the enzyme samples.The results showed that the functional groups were different at some specific wavelengths,indicating that the structure of the samples with the enzyme-free treatment was subtle.Furthermore,IgG treated with ?-galactosidase and?-galactosidase had a change in secondary structure compared with IgG without enzymetreatment.