Further Studies Relating Liver Xanthine Oxidase to Quality of Dietary Protein

Abstract

Studies with a deficient protein, gliadin, have indicated that the response in liver xanthine oxidase as a basis for measuring protein quality is very sensitive to changes in the state of the protein with respect to its amino acid composition. Calculation of the enzyme response constant has been analyzed and revised to represent a refined value for protein quality. Enzyme studies with casein, whole gliadin, and gliadin supplemented with various amino acids concur very well with similar studies where growth has been used as a criterion.