Acylation of Food Proteins and Hydrolysis by Digestive Enzymes: A Review

Abstract

The acylation of proteins involves the covalent attachment of acyl groups such as fatty acids and amino acids to both α‐ and ε‐amino groups of the polypeptide chain. Chemical methods are currently used to covalently attach amino acids to casein via isopeptide bonds. By modifying food proteins with acylation, it is possible to increase the nutritional value of the protein, judging from growth tests on rats. Enzymatic methods via transglutaminase and human placental factor XIII for preparing protein derivatives have also been tested. In vitro hydrolysis studies using intestinal homogenates have indicated that the intestinal mucosal hydrolases efficiently cleave acylated proteins as well as ε‐peptide bonds. Hog intestinal aminopeptidase N, as well as N‐acylpeptide hydrolase and acylase I have been found to be responsible for the biological utilization of N‐acylated food proteins.

Modification of plant proteins for improved functionality: A review

“…Acylation is a chemical derivatization technique, which has been widely applied to modify the functional properties of plant proteins and the reaction involves the transfer of an acyl group to the amino or hydroxyl groups of amino acid residues (Aryee, Agyei, & Udenigwe, 2018; Ferjancic‐Biagini, Giardina, & Puigserver, 1998). Protein acylation is expressed with different nomenclature depending on the acylating agent and the amino/hydroxyl group to which the acylating agent is attached.…”

Chemical and Enzymatic Protein Modifications and Functionality Enhancement

“…When an N-carboxy-amino acid anhydride or an N-hydroxysuccinimide ester of a tert-butyloxycarbonyl amino acid is used, an amino acid can be incorporated into the ε-amino group of the N-terminal amino acid by a peptide bond or into the ε-amino group of lysine by an isopeptide bond (Figure 7.3) (Ferjancic-Biagini, Giardina, and Puigserver 1998;Puigserver et al 1979a). The protein efficiency ratio of L-methionylcasein, in which L-methionine is covalently attached to the ε-amino group of lysine in casein, is almost equivalent to that of casein supplemented with free L-methionine, indicating the cleavage of the isopeptide bond between the ε-amino group of lysine and methionine in vivo (Puigserver et al 1979b).…”

“…Acyl group amino acid (Puigserver et al 1979a(Puigserver et al , 1979bFerjancic-Biagini, Giardina, and Puigserver 1998) can be used to incorporate an amino acid into the amino group of a protein.…”

Casein‐based conjugates and graft copolymers. Synthesis, properties, and applications

“…It is noteworthy that dietary proteins are often naturally N ‐acylated, as covalent attachment of several acyl groups, including fatty acids acyl groups, is present in many plants and animals cells (Ferjancic‐Biagini et al., 1998). Free amine functions of casein can react with activated carboxylic acids to give new amide groups.…”