Opioid activities and structures of .alpha.-casein-derived exorphins

Loukas, Spyros; Varoucha, D.; Zioudrou, Christine; Streaty, Richard A.; Klee, Werner A.

doi:10.1021/bi00288a034

Cited by 157 publications

(72 citation statements)

References 34 publications

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“…Three a s -casein-derived exorphins, which typically correspond to bovine a s1 -casein f90-95, f90-96 and f91-96, were found to be d-selective receptor ligands (Loukas, Varoucha, Zioudrou, Streaty, & Klee, 1983).…”

Section: Opioid Peptidesmentioning

confidence: 95%

Caseins as source of bioactive peptides

Silva

Malcata

2005

International Dairy Journal

378

211

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Biologically active peptides are of particular interest in food science and nutrition because they have been shown to play physiological roles, including opioid-like features, as well as immunostimulating and anti-hypertensive activities, and ability to enhance calcium absorption. Hidden or inactive in the amino-acid sequence of dairy proteins, they can be released or activated in vivo during gastrointestinal digestion, or upstream during food processing via specific, enzyme-mediated proteolysis. Caseins, in either milk or dairy products (e.g. cheese), are important sources of those peptides; their biological significance, their impact on human health and the manufacture of novel functional food ingredients therefrom have been subject to intensive research, which will be briefly presented and critically discussed in this review. r

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Section: Opioid Peptidesmentioning

confidence: 95%

Caseins as source of bioactive peptides

Silva

Malcata

2005

International Dairy Journal

378

211

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“…For instance, the structure and activity of opiod peptides have been identified within the primary sequence of both dietary and exocrine protein sources (Brantl et al 1979;Zioudrou et al 1979;Loukos et al 1983). These peptides, three to five amino acids in length, are resistant to digestion, modulate gastrointestinal motility, appetite and endocrine metabolism by binding to specific receptors (Froetschel 1996).…”

Section: Other Peptides and Hormonesmentioning

confidence: 99%

Regulation of intestinal glucose absorption: A new issue in animal science

Croom¹,

McBride²,

Bird³

et al. 1998

Can. J. Anim. Sci.

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, I. L. 1998. Regulation of intestinal glucose absorption: A new issue in animal science. Can. J. Anim. Sci. 78: 1-13. Intestinal glucose absorption occurs via Na + -dependent glucose cotransporters (SGLT1) located in the luminal membrane of enterocytes and is driven by an electrochemical gradient maintained by Na + /K + ATPase located on the basolateral membrane. Twenty percent of whole animal energy expenditures can be accounted for by the gastrointestinal tract, most of which is the result of Na + /K + ATPase function. Active intestinal glucose transport is regulated by a number of gastrointestinal peptides such as epidermal growth factor (EGF) and peptide YY (PYY). PYY and EGF can upregulate intestinal glucose absorption by as much as 200-300%. Of special interest is the fact that the energetic costs of intestinal tissue function can vary in relationship to the amount of glucose transported. This value termed "apparent energetic efficiency of glucose uptake" (APEE) may be of value in evaluating the energetic costs of glucose and other nutrients during various physiological and nutritional states. Recent studies suggest that intensive genetic selection for production traits in poultry may result in intestinal absorption being rate-limiting for full phenotypic expression of these traits. Further research is needed to clarify this issue.Key words: Glucose absorption, intestinal, energy metabolism, peptides, genetic selection Croom, W. J., Jr., McBride, B., Bird, A. R., Fan, Y.-K., Odle, J., Froetschel, M. et Taylor, I. L. 1998. Régulation de l'absorption du glucose dans l'intestin : un nouveau sujet de recherche zootechnique. Can. J. Anim. Sci. 78: 1-13. L'absorption du glucose dans l'intestin se fait par des transporteurs de type SGLT1 situés dans la membrane luminale des entérocytes et est activitée par un gradiant électrochimique maintenu par la Na + /K + ATPase située sur la membrane basolatérale. Vingt pour cent des dépenses en énergie de l'animal proviennent du tractus gastrointestinal et la quasi-totalité résultent de l'activité de la Na + /K + ATPase. Le transport actif du glucose dans l'intestin est modulé par un certain nombre de peptides gastrointestinaux comme le facteur de croissance épidermique (EGF) et le peptides YY (PYY). Ces deux derniers peuvent activer l'absorption de glucose dans l'intestin jusqu'à concurrence de 200 à 300 %. Particulièrement intéressant est le fait que les coûts énergétiques de l'activité des tissus intestinaux peuvent varier selon la quantité de glucose transportée. Cette valeur désignée par le terme "efficience énergétique apparente de l'absorption du glucose (APEE)" peut être utile pour évaluer les coûts énergétiques du glucose et d'autres nutriments durant divers états physiologiques et nutritionnels de l'animale. Les recherches récentes indiquent qu'une sélection génétique intensive axée sur les caractères de production en aviculture peut faire que l'absorption intestinale devienne un facteur limitant pour la pleine expression phénotypique de ces caractères. Cette que...

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“…Different strategies for identifying bioactive peptides in milk proteins have been employed : first, isolation and characterization of bioactive peptides from the gastrointestinal tract in vivo [19,201. The second strategy for seeking bioactive sequences is the isolation and characterization of bioactive peptides from in vitro digests of proteins [8,23,31,36,511. A third strategy using peptide synthesis is very useful in order to elucidate the bioactive structures of distinct amino acid sequences [12, 23, 32, 37, 401. Many known bioactive peptides are, biologically, very potent, so that even trace amounts of liberated peptides might be sufficient to exert physiological effects.…”

Section: Analytical Aspects Of Bioactive Peptidesmentioning

confidence: 99%

Bioactive peptides derived from milk proteins. Structural, physiological and analytical aspects

Schlimme¹,

Meisel²

1995

Nahrung

207

130

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The primary function of dietary proteins is to supply the body adequately with indispensable amino acids and organic nitrogen. Little attention has been paid up to date to milk proteins, in particular caseins, that are currently the main source of biologically active peptides, although other animal as well as vegetable proteins are known to contain potentially bioactive sequences. Such regulatory peptides can be released by enzymatic proteolysis of caseins in vitro and in vivo and may act as potential physiological modulators of metabolism during the intestinal digestion of the diet. It has been proved that bioactive peptides derived from caseins, such as beta-casomorphins and phosphopeptides, can be released during gastrointestinal passage. It is also evident that peptides originating from food proteins should be taken into account as potential modulators of various regulatory processes in the body. The possible regulatory effects concern nutrient uptake (phosphopeptides, casomorphins), postprandial hormone secretion (casomorphins), immune defense (immunopeptides, casokinins, casomorphins) and neuroendocrine information transfer (casokinins). The advances in the research field of bioactive peptides are driven by a molecular understanding of biological processes, and analytical techniques are a critical component of this understanding. Different up-to-date methods, including peptide synthesis and immunochemistry, have been applied to the chemical characterization of bioactive peptides. Especially casein derived peptides have already found interesting applications, both as dietary supplements (phosphopeptides) and as pharmaceutical preparations (phosphopeptides, beta-casomorphins). The question of 'what kinds of bioactive peptides are beneficial and desirable as food constituents or as drugs' should be always carefully examined. However, the possibilities for the design of dietary products and 'natural' drugs look promising.

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Opioid activities and structures of .alpha.-casein-derived exorphins

Cited by 157 publications

References 34 publications

Caseins as source of bioactive peptides

Caseins as source of bioactive peptides

Regulation of intestinal glucose absorption: A new issue in animal science

Bioactive peptides derived from milk proteins. Structural, physiological and analytical aspects

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