Biochemical, molecular and physiological characterization of a new beta-casein variant detected in Korean cattle.
There are seven known genetic variants of bovine beta-casein (beta-CN)--A1, A2, A3, B, C, D and E. In this study, we identified a new genetic variant (named beta-CN H) which migrates slower than the other variants in acidic starch gel electrophoresis. We confirmed through protein and DNA sequence analyses that the H variant differs at five residues from the A2 sequence: Arg25/Cys, Leu88/Ile, Gln117/Glu, Glu175/Gln and Gln195/Glu. Of these substitutions the 25th residue was contained in the casein phosphopeptide (CPP) region. In rats, calcium solubilizing effect of the CPP of bovine variant H was increased by approximately 23% compared with that of the CPP of non-H. Using extensive Korean Bos taurus pedigrees, we confirmed that beta-CN H was controlled by a codominant allele.
Han
S K
SK
Department of Dairy Science, College of Animal Husbandry, Kon-Kuk University, Seoul, Korea.
Shin
Y C
YC
Byun
H D
HD
D000818:Animals; D002364:Caseins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D002417:Cattle / Q000235:genetics*; D004587:Electrophoresis, Agar Gel; D014644:Genetic Variation; D008297:Male; D010375:Pedigree; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D051381:Rats; D017208:Rats, Wistar; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein
D002364:Caseins