Covalent attachment of amino acids to casein. 1. Chemical modification and rates of in vitro enzymic hydrolysis of derivatives

Puigserver, Antoine; Sen, Lourminia C.; Gonzales-Flores, Elvira; Feeney, Robert E.; Whitaker, John R.

doi:10.1021/jf60225a047

Cited by 36 publications

(29 citation statements)

References 41 publications

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“…Casein (54) and soybean proteins (45) have been modified by covalent attachment of various L-amino acids and methionine and tryptophan, respectively. Casein was selected as a model food protein for deliberate modification of its hydrophobic and hydrophilic groups and subsequent examination of changes in its physical and nutritional properties and digestibility.…”

Section: Covalent Binding Of Ami No Acidsmentioning

confidence: 99%

“…The resultant bond is either a peptide (for alpha-ami no nucleophile) or an isopeptide (epsilon-amino nucleophile). The N-hydroxy-succi namide esters of tert-butoxycarbonyl-Lamino acids (boc), both hydrophobic (glycine, alanine, methionine, N-acetyl-methionine) and hydrophilie (asparagine, asparatic acid), have been found to be quite effective in covalent attachment to casein (54). The chemistry employed in this case yields peptidylproteins only with non poly-peptidy1-derivatives.…”

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confidence: 99%

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Chemical Modification of Food Proteins

Shukla

1982

ACS Symposium Series

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During the past decade, a number of non-conventional proteins have been identified as human food ingredients, e.g., single-cell proteins, fish, leaf, and cereal concentrates, and soybeans, cottonseeds, and rapeseeds. Successful utilization of these new proteinaceous materials depends on their digestibility, nutritive value, and overall functional and organoleptic properties as related to processed food formulations. Many of them, although to varying degrees, fail to meet one or more such utilization criteria.Although the science, much less the art and technology, of chemical modification of food proteins is in its infancy, there exists a potential for the use of existing fundamental knowledge on protein derivatization -modification, replacement, and remov al of amino acid residues, and protein-lipid, protein-carbohy drate, and protein-ligand interactions for commercially viable food products and process research. Such research programs may lead to the development of modified food-grade proteins of improved functionality, nutritive value, and organoleptic quality and of reduced propensity to deterioration by physicochemical agents. This chapter is a review of 1) theory and known mecha nisms of modification, 2) applied and basic research on chemical modification of food proteins, 3) interaction of modified proteins with other food ingredients and 4) legal, regulatory, public health, and consumer acceptance implications of modified food protein products. In general, future research must address three major objectives: 1) selecting a structure-function specific modification scheme; 2) developing a process and product control strategy from commercial standpoints; and 3) testing the efficacy and safety of the product for human consumption. Chemistry of Food Protein ModificationFood protein structure. The knowledge of food protein struc ture, its capacity for covalent and non-covalent interactions, and structure-function relationships in the native state must be 0097-6156/82/0206-0275$07.75/0

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Section: Covalent Binding Of Ami No Acidsmentioning

confidence: 99%

mentioning

confidence: 99%

Chemical Modification of Food Proteins

Shukla

1982

ACS Symposium Series

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“…The chemical grafting of essential amino acids through their cr-carboxyl to the &-amino group of the lysyl residues of food proteins has resulted in the formation of a so-called isopeptide bond [6], which has further been shown to be readily hydrolyzable by intestinal brush border aminopeptidase N [7, 81. This finding is of great interest since membrane-bound aminopeptidase accounts for practically a11 the peptidase activity of the intestinal mucosa 19, lo], thus explaining how covalently attached amino acids happen to be available as well as the free forms.…”

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confidence: 99%

Oligo(methionyl) proteins

Gaertner

Puigserver

1984

European Journal of Biochemistry

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A number of model isopeptides containing oligo(methionine) chains varying in length (2 -5 residues) covalently linked to the &-amino group of lysine were synthesized by solid-phase procedures. Hydrolysis of these peptides by pepsin, chymotrypsin, cathepsin C (dipeptidyl peptidase IV) and intestinal aminopeptidase N was investigated using high-performance liquid chromatography to identify and quantify the hydrolysis products. Methionine oligomers grafted onto lysine were cleaved to tripeptides by pepsin. Chymotrypsin preferentially hydrolyzed the methionyl-methionine bond preceding the isopeptide bond. Cathepsin C released dimethionyl units from the covalently attached polymers. Intestinal aminopeptidase caused efficient hydrolysis of both peptides and isopeptide bonds although free methionine decreased the cleavage of the latter bond. Hydrophobic characteristics of oligo(methionine) chains promoted enzyme-catalyzed transpeptidations resulting probably from acyl-transfertype reactions. Complementary hydrolysis of the isopeptides by these digestive enzymes suggests that covalent attachment of oligo(amino acid)s to food proteins may improve their nutritional value.

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“…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.…”

Section: Lysine Cysteine Serine Reoninetyrosine Acylationmentioning

confidence: 99%