Isocratic reversed-phase high-performance liquid chromatographic separation of underivatised tyrosine-related peptides of thymopoietin32–36 pentapeptide

Tischio, John P.; Hetyei, Nancy

doi:10.1016/s0021-9673(00)82522-4

Cited by 7 publications

(1 citation statement)

References 14 publications

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“…This was achieved by reverse-phase chromatography using an HPLC system since quantitative estimation of methionine and methionine oligomers was found to be possible in a wide concentration range. Although HPLC has already been widely used for separating peptides and related derivatives on a qualitative analytical scale [20-231, only a few studies have dealt with its use from a quantitative standpoint [24].…”

Section: Discussionmentioning

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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Section: Discussionmentioning

confidence: 99%