The Minor Proteins of Bovine Milk

Abstract

A review of published information on the minor proteins of bovine milk is presented with emphasis on the physical and chemical structure. The following proteins were adequately shown to be native constituents of milk, prepared in crystalline or very pure form, and some knowledge is available concerning their composition, structure and properties: xanthine oxidase, lactoperoxidase A and B, alkaline phosphomonoesterase, and trypsin inhibitor. Other proteins which were also proven to be native components of milk but were not prepared in a pure form are: proteose, [alpha]-amylase. lipases, esterases, lactinin I and II. Additional proteins which were observed in milk but were not definitely proven to be native to bovine milk or adequately purified for characterization include: phosphodiesterase, two pyrophosphatases, two acid phosphomonoesterases, and antibacterial factor different from the lactinins, a lysozyme, [beta]-amylase, peptidase, catalase, a lactose-destroying enzyme, salolase, aldolase, carbonic anhydrase, rhodonase, a red protein, [delta] -casein, a copper protein, [zeta]-proteose, and the solar-activated flavor precursor.