Structures of the Peptide Leu-Pro-Tyr-Pro and Its Derivatives and the Nicotinamide Part of NADPH by a Semi-Empirical PM3 Method

Abstract

was analyzed using results from a semi-empirical PM3 method. The similarity of the peptide structures to NADPH was determined by comparing the relative contribution from projections of selected bond lengths in the peptides in two mutually perpendicular planes to the corresponding bond lengths in the nicotinamide part of the substrate. The correlation coefficient between the calculated average values of the relative contributions of the bonds and the inhibitory activity of these peptides is rather high (R = 0.926). This indicates that these peptides can occupy the part of the binding site for NADPH in the active center of the enzyme.

Fermented Soybean Products and Their Bioactive Compounds

“…Our results indicate a positive correlation between the binding of cholic and deoxycholic acids and the hypocholesterolemic effects of the pepsin hydrolyzate peptide (IAVPGEVA), while peptide hydrolyzates from trypsin digestion (LPYP and LPYPR) had hypocholesterolemic effects and gave a negative correlation for binding of bile acids. Therefore, the degree of interaction of bile acids is not ssential for identifying hypocholesterolemic activity (Pak et al, 2005a(Pak et al, , 2005b.…”

“…We started with the knowledge that these peptides contain a proline unit [2] in the fourth residue from the N-terminus (this is the same in IAVP and IAVPTGVA or IAVPGEVA). Such a sequence may play an important role in HMGR inhibition (Pak et al, 2005a(Pak et al, , 2005b. On the other hand, proline is the only unit with an aliphatic ring containing both the main and side chains.…”

“…We compared the peptide structures with those of the nicotinamide part of NADPH using data from an x-ray structure analysis of the enzyme active center with NADP + (Istvan & Deisenhofer, 2000a, 2000bIstvan et al, 2000) and selected four atoms (C4, O8, N9, O6') with the shortest H-bond distances. The peptide structures and their conformations calculated using AM1, PM3 and MNDO (Pak et al, 2005a(Pak et al, , 2005b. 1 2 The steric similarity of these structures were determined by calculating the percent of the projections of the selected bonds of the peptides to the corresponding bonds in the nicotinamide part of NADPH in two mutually perpendicular planes.…”

Avaliação de biodisponibilidade e mecanismos de ação hipocolesterolemizante de peptídeos do amaranto (Amaranthus cruentus L. BRS-Alegria)

“…Em condições como a utilização de enzimas peptidases, pH e taxas de enzima e substrato adequadas, a técnica in vitro gera resultados complementares às técnicas in vivo (MULLALLY et al, 1996;QIAO et al, 2004). A determinação enzimática da digestibilidade da proteína tem sido observada como correlata com estudos in vivo (HSU et al, 1977;HUR et al, 2011 Fatores que interferem da digestão proteica incluem interações de proteínas com polifenóis, fitatos, carboidratos, lipídeos e inibidores de peptidases que podem afetar a digestibilidade de proteínas; fatores relacionados às propriedades estruturais da proteína (IKEDA et al, 1986;DUODU et al, 2003) (MATSUI et al, 1993;LI et al, 2002;YOSHIKAWA et al, 2003;SGARBIERI, 2004 (NAGAOKA et al, 2001;DZIUBA et al, 2003;TAKENAKA et al, 2003;PAK et al, 2005a;PAK et al, 2005b). NAGAOKA e colaboradores 2010 FERNÁNDEZ-GARCÍA et al, 2009).…”