The identification and characterization of a truncated goat beta-casein, associated with a null beta-casein allele (CSN2(O')), is reported. The truncated beta-casein predicted at the DNA level (NCBI Acc. No. CAB39313) but never observed at the protein level, here named beta-casein O, was detected as a minor component in a goat milk sample from an autochthonous breed from southern Italy, 'Rossa Mediterranea', by reversed-phase high-performance liquid chromatography/electrospray ionization mass spectrometry (RP-HPLC/ESI-MS). The ESI mass spectrum of the intact beta-casein O determined an M, value of 18 780 Da (calculated 18781.5). Characterization of the amino acid sequence, performed by coupling trypsin digestion with matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), RP-HPLC/ESI-MS and tandem mass spectrometry (MS/MS), demonstrated that the amino acid sequence corresponds to the 1-166 sequence of mature beta-casein variant A (Acc. No. P33048), thus confirming that the protein is coded by the null allele CSN2(O'), characterized by a transition (C --> T) at the 373rd nucleotide of the 7th exon of the gene, which generates a premature stop codon in position 182.
|Titolo:||DETECTION AND CHARACTERIZATION BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY AND MASS SPECTROMETRY OF A GOAT β-CASEIN ASSOCIATED WITH A CSN2 NULL ALLELE|
|Data di pubblicazione:||2005|
|Citazione:||DETECTION AND CHARACTERIZATION BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY AND MASS SPECTROMETRY OF A GOAT β-CASEIN ASSOCIATED WITH A CSN2 NULL ALLELE / CUNSOLO V; GALLIANO F; MUCCILLI V; SALETTI R; MARLETTA D; BORDONARO S; FOTI S. - In: RAPID COMMUNICATIONS IN MASS SPECTROMETRY. - ISSN 0951-4198. - 19:20(2005), pp. 2943-2949.|
|Appare nelle tipologie:||1.1 Articolo in rivista|