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Wyszukujesz frazę "oxytocin" wg kryterium: Temat


Wyświetlanie 1-3 z 3
Tytuł:
Oxytocin analogues with amide groups substituted by tetrazole groups in position 4, 5 or 9
Autorzy:
Manturewicz, Michał
Grzonka, Zbigniew
Borovičková, Lenka
Slaninová, Jiřina
Powiązania:
https://bibliotekanauki.pl/articles/1040873.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
oxytocin analogues
SAR
tetrazole derivatives
Opis:
Eleven oxytocin analogues substituted in position 4, 5 or 9 by tetrazole analogues of amino acids were prepared using solid-phase peptide synthesis method and tested for rat uterotonic in vitro and pressor activities, as well as for their affinity to human oxytocin receptor. The tetrazolic group has been used as a bioisosteric substitution of carboxylic, ester or amide groups in structure-activity relationship studies of biologically active compounds. Replacement of the amide groups of Gln4 and Asn5 in oxytocin by tetrazole analogues of aspartic, glutamic and α-aminoadipic acids containing the tetrazole moiety in the side chains leads to analogues with decreased biological activities. Oxytocin analogues in which the glycine amide residue in position 9 was substituted by tetrazole analogues of glycine had diminished activities as well. The analysis of differences in rat uterotonic activity and in the affinity to human oxytocin receptors of analogues containing either an acidic 5-substituted tetrazolic group or a neutral 1,5- or 2,5-tetrazole nucleus makes it possible to draw some new conclusions concerning the role of the amide group of amino acids in positions 4, 5 and 9 of oxytocin for its activity. The data suggest that the interaction of the side chain of Gln4 with the oxytocin receptor is influenced mainly by electronic effects and the hydrogen bonding capacity of the amide group. Steric effects of the side chain are minor. Substitution of Asn5 by its tetrazole derivative gave an analogue of very low activity. The result suggests that in the interaction between the amide group of Asn5 and the binding sites of oxytocic receptor hydrogen bonds are of less importance than the spatial requirements for this group.
Źródło:
Acta Biochimica Polonica; 2007, 54, 4; 805-811
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of modification at position 2 on the side-chain conformation in oxytocin analogs
Autorzy:
Śmiech, Bogusław
Kaźmierkiewicz, Rajmund
Lammek, Bernard
Powiązania:
https://bibliotekanauki.pl/articles/1041276.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
oxytocin analogs
torsional angle distribution
EDMC
Opis:
The nonapeptide oxytocin (OT) is used in medicine to help begin and/or continue childbirth. Its analogs can be also used to control bleeding following fetus delivery. The main function of oxytocin is to stimulate contraction of uterus smooth muscle and the smooth muscle of mammary glands, thus regulating lactation. This paper describes theoretical simulations of the distribution of the torsional angles χ1 in the non-standard methylated phenylalanine residues of three oxytocin analogs: [(Phe)2o-Me]OT, [(Phe)2m-Me]OT, [(Phe)2p-Me]OT. The conformations of the oxytocin analogs were studied both in vacuum and in solution. We found some correlations between the biological activity of the considered peptides and the side-chain conformations of amino-acid residues 2 and 8.
Źródło:
Acta Biochimica Polonica; 2006, 53, 1; 113-120
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Molecular modelling study of the role of cholesterol in the stimulation of the oxytocin receptor.
Autorzy:
Politowska, Ewa
Kaźmierkiewicz, Rajmund
Wiegand, Volker
Fahrenholz, Falk
Ciarkowski, Jerzy
Powiązania:
https://bibliotekanauki.pl/articles/1044168.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
cholesterol
AutoDock 2.4
cholecystokinin receptor type β
oxytocin receptor
GPCR
sterols
Opis:
Cholesterol, an integral component of membranes in Eucaryota, is a modifier of membrane properties. In vivo studies have demonstrated that cholesterol can also modulate activities of some G protein-coupled receptors (GPCRs), which are integral membrane proteins. This can result either from an effect of cholesterol on the membrane fluidity or from specific interactions of the membrane cholesterol with the receptor, as recently demonstrated for the cholecystokinin type β (CCKRβ) or the oxytocin receptor (OTR). Using molecular modelling, we studied conformational preferences of cholesterol and several of its analogues. Subsequently, we simulated the distributions of their preferred conformations around the surface of OTR, CCKRβ and a chimeric oxytocin/cholecystokinin receptor. Consequently, we suggest residues on the surface of OTR which are potentially significant in the OTR/cholesterol interaction.
Źródło:
Acta Biochimica Polonica; 2001, 48, 1; 83-93
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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