Properties And Purification Of Ovotransferrin

Ovotransferrin(OVT), a bird-egg-white originated monomeric glycoprotein withits approximate molecular weight of78–80kDa and content of686amino acidresidues, accounts for about12%of total egg white proteins, and it has the capacityof improving hosts’ immol/Lunity, killing bacteria, killing viruses and preventinghosts from anemia.In this dissertation, the first research part entails the comparation of two differentmethods of extracting OVT from egg white (method1: ion-exchangechromatography followed by gel-exclusion chromatography; method2: ethanolextraction combined with ion exchange chromatography) by SDS-PAGEelectrophoresis and weight determination. The second part involves in evaluating theOVT’s binding capacity for4kinds of transitional metal ions (Cr3+, Fe3+, Cu2+andZn2+). At the ending part, orthogonal test in which concentration of substrate,enzyme-to-substrate ratio, enzymolysis time, temperature and pH have been taken asfactors, and Escherichia Coli growth inhibition ratio as effects, has beenimplemented to optimize trypsin’s enzymolysis conditions for production ofOVT-originated antimicrobial peptide.The results show that: method1could have higher yield of OVT than method2and its yield could be90.66%and recovery rate of OVT be64.6%; Under theconditions of pH9.0the existence of HCO--3, metal ion—HCO3—OVT complexwould be easily formed and the sequence of its binding capacity to transitional metalion was Cr3+> Fe3+=Cu2+> Zn2+; The best enzymolysis conditions for producingantimicrobial peptides were30mg/mL substrate concentration,1:300enzyme tosubstrate ratio,1.5h enzymolysis time,55℃, pH8.5and the final product’santibacterial rate is87.152%.