Immunostimulating hexapeptide from human casein: amino acid sequence, synthesis and biological properties

Abstract

A hexapeptide obtained from human casein by enzymatic digestion has been purified, sequenced and synthesized; its structure is: Val‐Glu‐Pro‐Ile‐Pro‐Tyr. In vitro this hexapeptide stimulates the phagocytosis of opsonized sheep red blood cells by murine peritoneal macrophages. Administered intravenously to adult mice, it enhances the resistance to infection with Klebsiella pneumoniae.

Peptides du lait à activité biologique

“…Toutefois, à notre connaissance, démonstration n'a pas été faite, à ce jour, d'une action bactériosta-tique in vivo de la lactoferrine et de la sérotransferrine. Sur un autre plan, il est connu que les bifidobactéries prédomi-nent dans le tractus intestinal des enfants nourris au sein, que ces micro-organismes exercent un effet de barrière per- Par analogie avec les activités immunomodulantes de peptides produits par les bactéries, Parker et al (1984) se sont posé la question de l'éventuelle existence dans le premier aliment de l'être humain, à savoir le lait, de fractions d'activité similaire. Leur démarche très finaliste s'appuyait sur le constat de la résistance aux infections bactériennes du nouveau-né nourri au sein, à travers les âges, avant tout développement de la pharmacothéra-pie.…”

Peptides: Production, bioactivity, functionality, and applications

“…Parker et al (1984) detected a hexapeptide with amino acid sequence of VEPIPY with immunostimulatory effect. The Miyata et al, 1989;Murakami et al, 1991;Ohta et al, 1992;Kawabata et al, 1996;Osaki et al, 1999 Blood of immune-challenged and untreated mussels (Mytilus edulis) peptide was claimed to stimulate in vitro phagocytosis of sheep red blood cells by murine macrophages and to have in vivo protective effect in mice against lethal infection caused by Klebsiella pneumonia (Parker et al, 1984). On the other hand, application of bioactive peptides from different resources has been limited due to their potential antigenicity and immunoreactivity in the body.…”

“…In addition, an immunomodulatory peptide derived from zebrafish phosvitin has been suggested to upregulate the expression of the anti-inflammatory and downregulate the expression of the pro-inflammatory cytokine genes (Ding et al, 2012). Parker et al (1984) detected a hexapeptide with amino acid sequence of VEPIPY with immunostimulatory effect. The Miyata et al, 1989;Murakami et al, 1991;Ohta et al, 1992;Kawabata et al, 1996;Osaki et al, 1999 Blood of immune-challenged and untreated mussels (Mytilus edulis) peptide was claimed to stimulate in vitro phagocytosis of sheep red blood cells by murine macrophages and to have in vivo protective effect in mice against lethal infection caused by Klebsiella pneumonia (Parker et al, 1984).…”

Stimulation of human peripheral blood lymphocytes by bioactive peptides derived from bovine milk proteins

“…Casein phosphopeptides and casomorphins have already found interesting applications, both as pharmaceutical preparations and as dietary supplements. Casein derived immunopeptides including immunopeptides from aSl-casein (residues 194-199) and [3-casein (residues 63-68 and 191-193) have been shown to stimulate phagocytosis of sheep red blood cells by murine peritoneal macrophages, and to exert a protective effect against Klebsiella pneumoniae infection in mice after intravenous treatment [2,3]. There are various hypotheses about the physiological action of such peptides.…”