Synthesis and solution conformation of [Trp1, Val5]-angiotensin II

1977 ◽  
Vol 55 (1) ◽  
pp. 75-82 ◽  
Author(s):  
Peter W. Schiller
Keyword(s):  
Angiotensin Ii ◽  
Solid Phase ◽  
Fluorescence Emission ◽  
Resonance Energy ◽  
Tryptophan Fluorescence ◽  
Exchange Chromatography ◽  
Phase Method ◽  
Aqueous Environment ◽  
Solution Conformation ◽  
Intramolecular Distance

[Trp1, Val5]-Angiotensin II was synthesized by the solid-phase method and purified by partition chromatography on Sephadex G-25 and by ion-exchange chromatography on Sephadex SP-25. Relative to [Val5]-angiotensin II, the analog displayed 36% smooth muscle activity in a preparation of the superior mesenteric artery. Conformational aspects of the analog were revealed by fluorescence techniques. The fluorescence emission maximum at 350 nm suggests a completely aqueous environment for the tryptophanyl residue in [Trp1, Val5]-angiotensin II. Singlet–singlet resonance energy transfer between Tyr in position 4 and Trp in position 1 was evaluated for a calculation of the intramolecular distance between these two residues on the basis of the Förster equation. From the relative increase of tryptophan fluorescence a transfer efficiency of > 0.9 was obtained, which is compatible with the observed complete quenching of tyrosine fluorescence in the analog. The computed average intramolecular distance of < 8 Å precludes an extended conformation for the N-terminal sequence encompassing residues 1 through 4 at neutral pH and suggests the existence of a loop in this part of the molecule. The results are discussed in relation to the various models proposed for the solution conformation of angiotensin II.

Antagonists of angiotensin II containing N-methyl-L-alanine and DL-nipecotic acid in position 7

1979 ◽  
Vol 57 (7) ◽  
pp. 763-766 ◽  
Author(s):  
Graham J. Moore ◽  
Evelyn M. Ko
Keyword(s):  
Angiotensin Ii ◽  
Solid Phase ◽  
Exchange Chromatography ◽  
Phase Method ◽  
Rat Uterus ◽  
Nipecotic Acid ◽  
Solid Phase Method ◽  
Pressor Activity ◽  
Secondary Amino ◽  
Myotropic Activity

[1-sarcosine, 7-N-methyl-L-alanine, 8-isoleucine]-Angiotensin II and [1-sarcosine, 7-DL-nipecotic acid, 8-isoleucine]-angiotensin II were synthesized by the solid-phase method and purified by cation-exchange chromatography and high-pressure liquid chromatography. In the isolated rat uterus these analogs and < 0.1% of the myotropic activity of angiotensin II and inhibited angiotensin II with pA2 values of 8.2 and 7.8, respectively. In the rat pressor assay (vagotomized ganglion blocked rat) these analogs had 0.9 and 2.8%, respectively, of the pressor activity of angiotensin II. The results show that the proline residue in position 7 of [Sar1,Ile8]-angiotensin II may be replaced by other secondary amino acids without disrupting interactions at angiotensin II receptors.

Synthesis of hepatitis B surface antigen pre-S2 region fragments and studies on their immunogenicity

1988 ◽  
Vol 53 (11) ◽  
pp. 2952-2956 ◽  
Author(s):  
Bernard Lammek ◽  
Zbigniew Maćkiewicz ◽  
Izabela Derdowska ◽  
Hanna Świderska ◽  
Adam Nowosławski ◽  
...  
Keyword(s):  
Hepatitis B ◽  
Surface Antigen ◽  
Solid Phase ◽  
Hepatitis B Surface Antigen ◽  
Gel Filtration ◽  
Exchange Chromatography ◽  
Antigenic Determinants ◽  
Phase Method ◽  
Peptide Fragments ◽  
Humoral Immune

Two peptide fragments of hepatitis B surface antigen pre-S2 region were synthesized by the solid phase method. The peptides were purified by gel filtration or ion-exchange chromatography on Sephadex SP-C-25. Both peptides induced a cellular and humoral immune response in rabbits. The results showed that fragment 14-22 of pre-S2 region contains one of the antigenic determinants.

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.

Synthesis of Peptides with the Solid Phase Method. II. Octapeptide Analogues of Angiotensin II

1974 ◽  
Vol 52 (2) ◽  
pp. 113-119 ◽  
Author(s):  
W. K. Park ◽  
C. Choi ◽  
F. Rioux ◽  
D. Regoli
Keyword(s):  
Blood Pressure ◽  
Biological Activity ◽  
Angiotensin Ii ◽  
Enzymatic Degradation ◽  
Solid Phase ◽  
Paper Electrophoresis ◽  
Antagonistic Effect ◽  
Phase Method ◽  
Solid Phase Method ◽  
Layer Chromatography

Forty-six analogues of angiotensin II were obtained with the solid-phase method for peptide synthesis. The peptides were purified, using the conventional procedures; homogeneity and purity were established after paper, thin-layer chromatography, paper electrophoresis, amino acid analysis, elemental analysis, and enzymatic degradation by aminopeptidase. The biological activity of all compounds was compared with that of angiotensin II on the blood pressure of anesthetized rats. The same test was used to establish the antagonistic effect of several analogues against angiotensin II.

Synthesis of peptides by the solid-phase method. V. Substance P and analogs

1980 ◽  
Vol 58 (4) ◽  
pp. 272-280 ◽  
Author(s):  
A. Fournier ◽  
R. Couture ◽  
J. Magnan ◽  
M. Gendreau ◽  
D. Regoli ◽  
...  
Keyword(s):  
Substance P ◽  
Solid Phase ◽  
Gel Filtration ◽  
Paper Electrophoresis ◽  
Exchange Chromatography ◽  
Phase Method ◽  
Elemental Analyses ◽  
Solid Phase Method

We have synthesized a series of 12 analogs of the undecapeptide substance P in order to perform a structure–activity study of this peptide. In the present work, each residue was substituted by L-alanine, and the C-terminal amide was replaced by the free carboxyl in order to pinpoint biologically important side chains and functional groups. The synthesis of the analogs was carried out by the automatic solid-phase method. Couplings were performed by the symmetrical anhydride procedure. After cleavage with liquid HF, the peptides were purified by gel filtration and ion-exchange chromatography. Their purity was assessed by thin-layer chromatography, paper electrophoresis, amino acid and elemental analyses, and high pressure liquid chromatography. They were tested for biological activity in vitro on the ileum of the guinea pig, the mesenteric vein of the rabbit, and the vas deferens of the rat, and in vivo by measuring their effect on the blood pressure of the rat.

Superficial disposition of the N-terminal region of the surfactant protein SP-C and the absence of specific SP-B–SP-C interactions in phospholipid bilayers

2001 ◽  
Vol 359 (3) ◽  
pp. 651-659 ◽  
Author(s):  
Inés PLASENCIA ◽  
Antonio CRUZ ◽  
Cristina CASALS ◽  
Jesús PÉREZ-GIL
Keyword(s):  
Emission Spectrum ◽  
Protein Interactions ◽  
Fluorescence Emission ◽  
Resonance Energy ◽  
Fold Increase ◽  
Blue Shift ◽  
Terminal Segment ◽  
Phospholipid Bilayers ◽  
Aqueous Environment ◽  
Fluorescence Emission Spectrum

A dansylated form of porcine surfactant-associated protein C (Dns-SP-C), bearing a single dansyl group at its N-terminal end, has been used to characterize the lipid–protein and protein–protein interactions of SP-C reconstituted in phospholipid bilayers, using fluorescence spectroscopy. The fluorescence emission spectrum of Dns-SP-C in phospholipid bilayers is similar to the spectrum of dansyl-phosphatidylethanolamine, and indicates that the N-terminal end of the protein is located at the surface of the membranes and is exposed to the aqueous environment. In membranes containing phosphatidylglycerol (PG), the fluorescence of Dns-SP-C shows a 3-fold increase with respect to the fluorescence of phosphatidylcholine (PC), suggesting that electrostatic lipid–protein interactions induce important effects on the structure and disposition of the N-terminal segment of the protein in these membranes. This effect saturates above 20% PG molar content in the bilayers. The parameters for the interaction of Dns-SP-C with PC or PG have been estimated from the changes induced in the fluorescence emission spectrum of the protein. The protein had similar Kd values for its interaction with the different phospholipids tested, of the order of a few micromolar. Cooling of Dns-SP-C-containing dipalmitoyl PC bilayers to temperatures below the phase transition of the phospholipid produced a progressive blue-shift of the fluorescence emission of the protein. This effect is interpreted as a consequence of the transfer of the N-terminal segment of the protein into less polar environments that originate during protein lateral segregation. This suggests that conformation and interactions of the N-terminal segment of SP-C could be important in regulating the lateral distribution of the protein in surfactant bilayers and monolayers. Potential SP-B–SP-C interactions have been explored by analysing fluorescence resonance energy transfer (RET) from the single tryptophan in porcine SP-B to dansyl in Dns-SP-C. RET has been detected in samples where native SP-B and Dns-SP-C were concurrently reconstituted in PC or PG bilayers. However, the analysis of the dependence of RET on the protein density excluded specific SP-B–Dns-SP-C associations.

Synthesis of Peptides by the Solid Phase Method. I. Tetradecapeptide Renin Substrate and Intermediate Peptides, Nonapeptides, and Fragments of Angiotensin II

1974 ◽  
Vol 52 (2) ◽  
pp. 106-112 ◽  
Author(s):  
W. K. Park ◽  
C. Choi ◽  
F. Rioux ◽  
D. Regoli
Keyword(s):  
Amino Acid ◽  
Angiotensin Ii ◽  
Enzymatic Degradation ◽  
Solid Phase ◽  
Reaction Vessel ◽  
Phase Method ◽  
Renin Substrate ◽  
Aminopeptidase M ◽  
Solid Phase Method ◽  
Solvent Systems

Tetradecapeptide renin substrate (H∙Asp-Arg-Val-Tyr-Ile-His-Pro-Phe-His-Leu-Leu-Val-Tyr-Ser∙OH) (1–14), tridecapeptide (1–13), dodecapeptide (1–12), undecapeptide (1–11), two nonapeptides (1–9) and (1–9-Leu), heptapeptide (1–7), tetrapeptide (1–4), tetrapeptide (5–8), pentapeptide (4–8), hexapeptide (3–8), and heptapeptide (2–8) were synthesized by the solid phase method and by using an improved reaction vessel. The yield averaged 50–70%. Homogeneity and purity of peptides were established with elemental anlysis for C, H, and N, paper chromatography in three solvent systems, electrophoresis, amino acid analysis, and enzymatic degradation by aminopeptidase M.

Synthesis of modified human C-peptide and its fragments

1988 ◽  
Vol 53 (11) ◽  
pp. 2637-2644 ◽  
Author(s):  
Běla Bendlová ◽  
Michal Lebl ◽  
Pavel Štolba ◽  
Luboslav Stárka
Keyword(s):  
Solid Phase ◽  
Gel Filtration ◽  
Reversed Phase ◽  
Exchange Chromatography ◽  
Phase Method ◽  
Reversed Phase Hplc ◽  
Radioactive Label ◽  
C Peptide ◽  
Solid Phase Method ◽  
Internal Marker

Syntheses of the modified human C-peptide containing residues suitable for the introduction of the radioactive label (tyrosine) and internal marker for monitoring binding to carrier (norvaline) and five of its fragments are described. The syntheses were performed by solid phase method using either 9-fluorenylmethoxycarbonyl or tert-butyloxycarbonyl protecting groups. The products were purified by gel filtration, ion exchange chromatography and reversed phase HPLC. The reactivity of prepared peptides with antisera was determined and the modified C-peptide was found fully reactive.

Structure–activity study of kinins in vascular smooth muscles

1981 ◽  
Vol 59 (4) ◽  
pp. 380-389 ◽  
Author(s):  
P. Gaudreau ◽  
J. Barabé ◽  
S. St-Pierre ◽  
D. Regoli
Keyword(s):  
Carotid Artery ◽  
Terminal Ileum ◽  
Common Carotid Artery ◽  
Solid Phase ◽  
Biological Activities ◽  
Gel Filtration ◽  
Smooth Muscles ◽  
Exchange Chromatography ◽  
Phase Method ◽  
Vascular Smooth Muscles

To explore further the relations between the chemical structure and the biological activities of kinins, a series of bradykinin fragments and analogues was prepared by the solid-phase method. Bradykinin and kallidin were also extended at the C- or the N-terminai end by the addition of one or more residues in order to evaluate the importance of peptide chain length and of additional positive charges at the N-terminal end for the biological activity. After purification by cation-exchange chromatography and gel filtration, the compounds were characterized by thin-layer chromatography, paper electrophoresis, elemental analyses, and amino acid analyses. All compounds were tested on three vascular preparations (the dog common carotid artery, the rabbit jugular vein, and the guinea pig anterior mesenteric vein) in order to measure their relative potencies as relaxant (on the dog common carotid artery) or as stimulant (the two veins) of vascular smooth muscles. The compounds were also tested on the cat terminal ileum and the rabbit aorta for comparison.The results reported in this paper indicate that all the new analogues of bradykinin as well as some fragments and analogues described before by us and by other workers are full agonists in the three vascular preparations. No partial agonists or antagonists have been identified. The order of potency of the various kinin analogues is similar in the three vascular preparations and follows the same pattern as that found in the cat terminal ileum. It is therefore concluded that (a) the three vascular preparations utilized in the present experiment possess a B2 receptor type that appears to be similar to that of the cat terminal ileum and of the rat uterus described before and (b) receptors of the B2 type are able to mediate both the inhibitory and the excitatory actions of kinins in vascular smooth muscles.

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