B. Lieske et G. Konrad, A NEW METHOD TO ESTIMATE CASEINOMACROPEPTIDE AND GLYCOMACROPEPTIDE FROM TRICHLOROACETIC-ACID FILTRATES, Milchwissenschaft, 51(8), 1996, pp. 431-435
A new approach to estimate caseinomacropeptide (CMP) as well as its gl
ycosylated part (GMP) was developed using rennet whey and two caseins
as substrates. The assay is based on a controlled solubilization of CM
P and GMP at trichloroacetic acid (TCA) concentrations of 6% and 12%,
respectively, followed by a desalting step on Econo Pak 10 DG. The res
ulting eluates were measured spectrophotometrically at 217 nm using 1
cm cuvettes. Calibration was carried out by renneting pure kappa-casei
n and analyzing the TCA filtrate according to the new procedure. The s
pectrophotometric results were compared with chromatographic findings
obtained by FPLC and a Mono S column. It was shown that (a) the spectr
ophotometric method does correlate with the peak areas of the chromato
graphic separations for CMP and (b) both procedures, the use of 6% TCA
in presence of 0.175 M Na2SO4 as well as the isoelectric precipitatio
n, are well comparing in their efficiency to solubilize CMP.