Study of caprine beta-casein using reversed-phase high-performance liquid chromatography and mass spectroscopy: identification of a new genetic variant.
The genotypes and the main phosphorylation levels of beta-casein of goat milk were studied using RP-HPLC/ESI-MS. A new variant of caprine beta-casein named E has been characterized using RP-HPLC/ESI-MS, MALDI-MS and NanoESI MS/MS methods. Its sequence differed from that of variant A in the mono amino acid substitution D47 --> Y47, which resulted in a 48 Da experimental mass difference between them. The calculated molecular mass of the new variant E 6 P was estimated as 23,869 Da. Its phosphorylation pattern was similar to that of variant A, the most abundant types being those with 5 and 6 P in similar quantities.
Moatsou
Golfo
G
Laboratory of Dairy Science and Technology, Department of Food Science and Technology, Agricultural University of Athens, Iera Odos 75, Athens, 118 55, Greece.
Mollé
Daniel
D
Moschopoulou
Ekaterini
E
Valérie
Gagnaire
G
D019943:Amino Acid Substitution; D000818:Animals; D002364:Caseins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D014644:Genetic Variation; D006041:Goats; D008892:Milk / Q000737:chemistry*; D008969:Molecular Sequence Data; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
D002364:Caseins