Abstract
Concerning the formation of a higher molecular fraction (HMF) from α-lactalbumin (α-La) during peptic digestion, the productivity of HMF from α-La which were treated with several proteases and chemical reagents was examined.
HMF was hardly formed when α-La was previously hydrolyzed by trypsin and/or chymotrypsin. The reaction between HMF and anti HMF serum was strongly inhibited by peptides with molecular weight less than 5, 000 dalton prepared from α-La digested with pepsin, trypsin or chymotrypsin.
On the other hand, the formation of HMF was drastically reduced by S-carboxymethylation or amidation of carboxyl groups of α-La, whereas nitration of 45 % hydroxyl groups of tyrosin in α-La decreased the production of HMF. HMF was more stable to peptic or chymotryptic hydrolysis than α-La.
