Polyacrylamide겔 전기영동법에 의한 유방염유의 whey protein 조성에 관한 연구

A study on whey protein composition of mastitis milk by polyacrylamide gel electrophoresis

Samples of normal and mastitis milk from Holstein cows of Chonbuk region were obtained and analyzed to compare the contents and compositions lf whey protein components of both milk samples by polyacrylamide gel electrophoresis and densitometric tracing. Samples of normal milk from Holstein cows were classified to 3 types by β-lactoglobulin comprised in whey protein; genetic AB type which contains both β-lactoglobulin A and B, genetic variant B type which contains only β-lactoglobulin B, and genetic variant A type which contains only β-lactoglobulin A. Whey proteins of normal milk were resolved into 3 major fractions with relative propoertions of approximately 69:15:16 for total β-lactoglobulin, α-lactalbumin, and serum albumin. There were no differences in the concentrations of total β-lactoglobulin of 3 milk types, although relative propoertion of β-lactoglobulin A and B in AB type was 69.4:30:6. Serum albumin contents in case with clinical mastitis milk were increased regardless of types of milk, and showed markedly elevated levels of 8~26 times compared with serum albumin levels in normal milk whey. Mastitis milk of AB type from Holstein cow with heavy clinical sign showed a disappearance of α-lactalbulin, but not in cases of mastitis milk from cow with other types of milk(A or B) and inassistained consistent levels. β-lactoglobulins such as β-lactoglobulin A and β-lactoglobulin B in mastitis milk with light clinical sign were not changed. But with the increase in the severity of mastitis β-lactoglobulin contents showed notably decreating trend. Total whey protein contents in all mastitis milk regardless of genetic variant types of milk appeared great increases. With the increase of the severity of mastitis the proportion of serum albumin was generally on a trend of the increase while the proportion of β-lactoglobulin appeared a trend of the decrease and α-lactalbumin did net show a significant alteration of relative proportion.