Ge. Arteaga et al., PARTIAL LEAST-SQUARES REGRESSION OF 4TH-DERIVATIVE ULTRAVIOLET ABSORBENCY SPECTRA PREDICTS COMPOSITION OF PROTEIN MIXTURES - APPLICATION TOBOVINE CASEINS, Journal of agricultural and food chemistry, 42(9), 1994, pp. 1938-1942
A method is described for the quantitative determination of the compos
ition of protein mixtures using fourth-derivative ultraviolet spectros
copy. The methodology was demonstrated by quantifying mixtures of the
three main bovine caseins (alpha(s1)-, beta-, and kappa-casein). The 2
44-296-nm spectra region of protein mixtures of known composition, dis
solved in 4 M guanidine hydrochloride, was used for the development of
prediction models using the multivariate method of partial least-squa
res regression analysis (PLSR), implemented in a commercial software.
The standard errors of prediction for 16 test samples were 13.4, 5.5,
and 11.9% for alpha(s1)-, beta-, and kappa-casein, respectively, and t
he correlations between measured and predicted composition were 0.91,
0.99, and 0.94 for the three proteins, respectively. This method was f
ound to be faster and simpler than alternate procedures (e.g., gel ele
ctrophoresis), suggesting the possibility of using this methodology as
a quality control tool in industrial protein fractionation environmen
ts.