Gastrin biosynthesis in canine G cells

2002 ◽  
Vol 282 (5) ◽  
pp. G766-G775 ◽  
Author(s):  
Vinzenz Stepan ◽  
Kentaro Sugano ◽  
Tadataka Yamada ◽  
Jung Park ◽  
Chris J. Dickinson
Keyword(s):  
Amino Acids ◽  
Ascorbic Acid ◽  
Biological Activity ◽  
Cell Line ◽  
Antisense Oligonucleotide ◽  
Prohormone Convertase ◽  
Posttranslational Processing ◽  
Oligonucleotide Probes ◽  
G Cells ◽  
Primary Cell Line

Gastrin requires extensive posttranslational processing for full biological activity. It is presumed that progastrin is cleaved at pairs of basic amino acids by a prohormone convertase to form a glycine-extended intermediate (G-Gly) that serves as a substrate for peptidyl-glycine α-amidating monooxygenase (PAM), resulting in COOH-terminally amidated gastrin. To confirm the nature of progastrin processing in a primary cell line, we performed [35S]methionine-labeled pulse-chase biosynthetic experiments in canine antral G cells. Radiolabeled progastrin reached a peak earlier than observed for G-Gly or amidated gastrin. G-Gly radioactivity accumulated in G cells and preceded the appearance of radioactivity in amidated gastrin. The conversion of G-Gly to amidated gastrin was enhanced by the PAM cofactor ascorbic acid. To determine whether one member of the prohormone convertase family (PC2) was responsible for progastrin cleavage, G cells were incubated with PC2 antisense oligonucleotide probes. Cells treated with antisense probes had reduced PC2 expression, an accumulation of radiolabeled progastrin, and a delay in the formation of amidated gastrin. Progastrin in antral G cells is cleaved via PC2 to form G-Gly that is converted to amidated gastrin via the actions of PAM.

Biological activity of progastrin posttranslational processing intermediates

1987 ◽  
Vol 252 (3) ◽  
pp. G315-G319 ◽  
Author(s):  
M. Matsumoto ◽  
J. Park ◽  
K. Sugano ◽  
T. Yamada
Keyword(s):  
Biological Activity ◽  
Binding Sites ◽  
Cell Types ◽  
Parietal Cells ◽  
Physiological Significance ◽  
Posttranslational Processing ◽  
Fundic Mucosa ◽  
G Cells ◽  
Carboxyl Terminal ◽  
D Cells

We recently identified carboxyl-terminally extended progastrin posttranslational processing intermediates in G cells of the gastric antrum and demonstrated that they are cosecreted with gastrin. To determine the physiological significance of these intermediates, we examined the biological activity of two synthetic gastrin precursor analogues that correspond to hexagastrin with carboxyl-terminal extensions, Tyr-Gly-Trp-Met-Asp-Phe-Gly (GL-7) and Tyr-Gly-Trp-Met-Asp-Phe-Gly-Arg-Arg (GL-9) on gastric parietal and D cells isolated from canine fundic mucosa. Both analogues were as efficacious as gastrin heptadecapeptide in displacing 125I-[Leu15]gastrin from binding sites on the two cell types and in stimulating [14C]aminopyrine uptake by parietal cells and somatostatin release from D cells. However, both analogues were 10(4)- to 10(5)-fold less potent than gastrin heptadecapeptide in these activities. Our results indicate that progastrin processing intermediates do not have physiologically relevant actions under normal circumstances and support the notion that carboxyl-terminally amidated peptides such as gastrin require the amide moiety for biological activity.

Synthesis of New α-Amino Phosphonates Containing 3-Amino-4(3H) Quinazolinone Moiety as Anticancer and Antimicrobial Agents: DFT, NBO, and Vibrational Studies

2018 ◽  
Vol 15 (2) ◽  
pp. 286-296 ◽  
Author(s):  
Mohamed K. Awad ◽  
Mahmoud F. Abdel-Aal ◽  
Faten M. Atlam ◽  
Hend A. Hekal
Keyword(s):  
Biological Activity ◽  
Cell Line ◽  
Quantum Chemical ◽  
Density Functional ◽  
Carcinoma Cell ◽  
Liver Carcinoma ◽  
Anticancer Activities ◽  
Functional Theory ◽  
Ft Ir ◽  
Good Agreement

Aim and Objective: Synthesis of new .-aminophosphonates containing quinazoline moiety through Kabachnik-Fields reaction in the presence of copper triflate catalyst [32], followed by studying their antimicrobial activities and in vitro anticancer activities against liver carcinoma cell line (HepG2) with the hope that new anticancer agents could be developed. Also, the quantum chemical calculations are performed using density functional theory (DFT) to study the effect of the changes of molecular and electronic structures on the biological activity of the investigated compounds. Materials and Method: The structures of the synthesized compounds are confirmed by FT-IR, 1H NMR, 13C NMR, 31P NMR and MS spectral data. The synthesized compounds show significant antimicrobial and also remarkable cytotoxicity anticancer activities against liver carcinoma cell line (HepG2). Density functional theory (DFT) was performed to study the effect of the molecular and electronic structure changes on the biological activity. Results: It was found that the electronic structure of the substituents affects on the reaction yield. The electron withdrawing substituent, NO2 group 3b, on the aromatic aldehydes gave a good yield more than the electron donating substituent, OH group 3c. The electron deficient on the carbon atom of the aldehydic group may increase the interaction of the Lewis acid (Cu(OTf)2) and the Lewis base (imine nitrogen), and accordingly, facilitate the formation of imine easily, which is attacked by the nucleophilic phosphite species to give the α- aminophosphonates. Conclusion: The newly synthesized compounds exhibit a remarkable inhibition of the growth of Grampositive, Gram-negative bacteria and fungi at low concentrations. The cytotoxicity of the synthesized compounds showed a significant cytotoxicity against the liver cancer cell line (HepG 2). Also, it was shown from the quantum chemical calculations that the electron-withdrawing substituent increases the biological activity of the α-aminophosphonates more than the electron donating group which was in a good agreement with the experimental results. Also, a good agreement between the experimental FT-IR and the calculated one was found.

Synthesis and biological activity of new metallocenic angiotensin II analogs

1988 ◽  
Vol 53 (11) ◽  
pp. 2914-2919 ◽  
Author(s):  
Pierrette Maes ◽  
Annie Ricouart ◽  
Emmanuel Escher ◽  
André Tartar ◽  
Christian Sergheraert
Keyword(s):  
Amino Acids ◽  
Biological Activity ◽  
Angiotensin Ii ◽  
Solid Phase ◽  
Rabbit Aorta ◽  
Phase Method ◽  
Solid Phase Method

Analogs of angiotensin II in which phenylalanine in position 8 was replaced with cymantrenylalanine or with its triphenylphosphine photosubstitution product were synthesized by the solid-phase method. On rabbit aorta strips, these peptides were found to be pure antagonists of angiotensin II. Their relative affinities are higher than most other analogs substituted in position 8 with bulky amino-acids.

scholarly journals Transforming growth factor alpha: mutation of aspartic acid 47 and leucine 48 results in different biological activities.

1988 ◽  
Vol 8 (3) ◽  
pp. 1247-1252 ◽  
Author(s):  
E Lazar ◽  
S Watanabe ◽  
S Dalton ◽  
M B Sporn
Keyword(s):  
Amino Acids ◽  
Biological Activity ◽  
Amino Acid ◽  
Growth Factor ◽  
Aspartic Acid ◽  
Transforming Growth Factor ◽  
Biologically Active ◽  
Single Amino Acid ◽  
Transforming Growth Factor Alpha ◽  
Factor Alpha

To study the relationship between the primary structure of transforming growth factor alpha (TGF-alpha) and some of its functional properties (competition with epidermal growth factor (EGF) for binding to the EGF receptor and induction of anchorage-independent growth), we introduced single amino acid mutations into the sequence for the fully processed, 50-amino-acid human TGF-alpha. The wild-type and mutant proteins were expressed in a vector by using a yeast alpha mating pheromone promoter. Mutations of two amino acids that are conserved in the family of the EGF-like peptides and are located in the carboxy-terminal part of TGF-alpha resulted in different biological effects. When aspartic acid 47 was mutated to alanine or asparagine, biological activity was retained; in contrast, substitutions of this residue with serine or glutamic acid generated mutants with reduced binding and colony-forming capacities. When leucine 48 was mutated to alanine, a complete loss of binding and colony-forming abilities resulted; mutation of leucine 48 to isoleucine or methionine resulted in very low activities. Our data suggest that these two adjacent conserved amino acids in positions 47 and 48 play different roles in defining the structure and/or biological activity of TGF-alpha and that the carboxy terminus of TGF-alpha is involved in interactions with cellular TGF-alpha receptors. The side chain of leucine 48 appears to be crucial either indirectly in determining the biologically active conformation of TGF-alpha or directly in the molecular recognition of TGF-alpha by its receptor.

scholarly journals Translational and Structural Requirements of the Early Nodulin Gene enod40, a Short-Open Reading Frame-Containing RNA, for Elicitation of a Cell-Specific Growth Response in the Alfalfa Root Cortex

2001 ◽  
Vol 21 (1) ◽  
pp. 354-366 ◽  
Author(s):  
Carolina Sousa ◽  
Christina Johansson ◽  
Celine Charon ◽  
Hamid Manyani ◽  
Christof Sautter ◽  
...  
Keyword(s):  
Amino Acids ◽  
Biological Activity ◽  
Rna Structure ◽  
Open Reading Frames ◽  
In Vitro Translation ◽  
Cortical Cells ◽  
Root Cortex ◽  
Reading Frame ◽  
Early Nodulin

ABSTRACT A diversity of mRNAs containing only short open reading frames (sORF-RNAs; encoding less than 30 amino acids) have been shown to be induced in growth and differentiation processes. The early nodulin geneenod40, coding for a 0.7-kb sORF-RNA, is expressed in the nodule primordium developing in the root cortex of leguminous plants after infection by symbiotic bacteria. Ballistic microtargeting of this gene into Medicago roots induced division of cortical cells. Translation of two sORFs (I and II, 13 and 27 amino acids, respectively) present in the conserved 5′ and 3′ regions ofenod40 was required for this biological activity. These sORFs may be translated in roots via a reinitiation mechanism. In vitro translation products starting from the ATG of sORF I were detectable by mutating enod40 to yield peptides larger than 38 amino acids. Deletion of a Medicago truncatula enod40 region between the sORFs, spanning a predicted RNA structure, did not affect their translation but resulted in significantly decreased biological activity. Our data reveal a complex regulation of enod40action, pointing to a role of sORF-encoded peptides and structured RNA signals in developmental processes involving sORF-RNAs.

scholarly journals Altered Proglucagon Processing in an α-Cell Line Derived from Prohormone Convertase 2 Null Mouse Islets

2004 ◽  
Vol 279 (30) ◽  
pp. 31068-31075 ◽  
Author(s):  
Gene C. Webb ◽  
Arunangsu Dey ◽  
Jie Wang ◽  
Jeffrey Stein ◽  
Margaret Milewski ◽  
...  
Keyword(s):  
Cell Line ◽  
Null Mouse ◽  
Prohormone Convertase ◽  
Prohormone Convertase 2 ◽  
Mouse Islets

scholarly journals Synthesis, structural analysis, solution equilibria and biological activity of rhodium(iii) complexes with a quinquedentate polyaminopolycarboxylate

RSC Advances ◽  
2017 ◽  
Vol 7 (9) ◽  
pp. 5282-5296 ◽  
Author(s):  
Marija S. Jeremić ◽  
Hubert Wadepohl ◽  
Vesna V. Kojić ◽  
Dimitar S. Jakimov ◽  
Ratomir Jelić ◽  
...  
Keyword(s):  
Biological Activity ◽  
Structural Analysis ◽  
Antitumor Activity ◽  
Hela Cell ◽  
Cell Line ◽  
Hela Cell Line ◽  
Solution Equilibria ◽  
Line P

Two new Rh(iii)–ed3a complexes [Rh(ed3a)(OH2)]·H2O and Na[Rh(ed3a)Cl]·H2O have shown good antitumor activity, especially against HeLa cell line.

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