- Collagen peptide, dipeptide and malady inhibitor
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A problem that the present invention is to solve is to provide: a main body of a peptide molecule which is effective for inhibition of various maladies such as osteoporosis, osteoarthritis and pressure ulcer, particularly, a dipeptide which is easy to absorb into a body in an intestine; a collagen peptide which comprises the dipeptide as an essential dipeptide; and a malady inhibitor which comprises the dipeptide as an essential effective component. As a means of solving such a problem, a collagen peptide according to the present invention is characterized by comprising a dipeptide having a structure of Hyp-Gly as an essential dipeptide. A dipeptide according to the present invention is characterized by having a structure of Hyp-Gly. A malady inhibitor according to the present invention is characterized by comprising a dipeptide having a structure of Hyp-Gly as an essential effective component.
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Page/Page column 7
(2011/07/29)
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- Inhibition and metal ion activation of pig kidney aminopeptidase P. Dependence on nature of substrate
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Pig kidney aminopeptidase P (AP-P; EC 3.4.11.9) has been purified to homogeneity after its solubilisation from brush border membranes by phosphatidylinositol-specific phospholipase C. The effects of various activators and inhibitors of AP-P activity have been examined with a number of different substrates for the enzyme. The hydrolysis of bradykinin and ArgProPro is inhibited at Mn2+ concentrations above 10-5 M, whereas the hydrolysis of other substrates (GlyProHyp, β-casomorphin, substance P) is substantially activated, with 4-10 mM Mn2+ being optimal. The thiol reagent, p-chloromercuriphenylsulphonic acid, inhibits the hydrolysis of GlyProHyp but markedly activates the hydrolysis of bradykinin. A number of inhibitors of angiotensin converting enzyme (ACE; EC 3.4.15.1), previously reported to inhibit the hydrolysis of GlyProHyp, have no effect on the hydrolysis of bradykinin except in the presence of Mn2+. Differences were also observed in the degree of inhibition of GlyProHyp and bradykinin hydrolysis by EDTA and their reactivation by divalent cations. The hydrolysis of GlyProHyp follows Michaelis-Menten kinetics with a K(m) value of 2.7 mM. Bradykinin inhibits GlyProHyp hydrolysis with an I50 of 1.4 μM. The hydrolysis of bradykinin by AP-P reveals anomalous nonlinear kinetics indicative of negative cooperativity or the presence of more than one active site for this substrate. These results indicate that substrates for AP-P can be divided into 2 groups based on their responses to inhibitors and cation activators.
- Lloyd, Georgina S.,Hryszko, John,Hooper, Nigel M.,Turner, Anthony J.
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p. 229 - 236
(2007/10/03)
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