scholarly journals From a Marine Neuropeptide to Antimicrobial Pseudopeptides Containing Aza-β3-Amino Acids: Structure and Activity

2012 ◽  
Vol 55 (5) ◽  
pp. 2025-2034 ◽  
Author(s):  
Mathieu Laurencin ◽  
Baptiste Legrand ◽  
Emilie Duval ◽  
Joël Henry ◽  
Michèle Baudy-Floc’h ◽  
...  
Keyword(s):  
Amino Acids ◽  
Structure And Activity

scholarly journals Studies on the structure and activity of rabbit C1q (a subcomponent of the first component of complement)

1974 ◽  
Vol 143 (2) ◽  
pp. 265-272 ◽  
Author(s):  
Diane M. Lowe ◽  
Kenneth B. M. Reid
Keyword(s):  
Amino Acids ◽  
Deae Cellulose ◽  
Exchange Chromatography ◽  
Haemolytic Activity ◽  
Subunit Structure ◽  
Carboxypeptidase A ◽  
Rapid Loss ◽  
Collagenase Digestion ◽  
Polypeptide Chains ◽  
Structure And Activity

1. The subunit structure of rabbit subcomponent C1q was examined in a previous publication (Reid et al., 1972). The present paper describes some aspects of the structure of the polypeptide chains derived from the molecule. 2. The three polypeptide chains, produced by performic oxidation, of rabbit subcomponent C1q were isolated by ion-exchange chromatography in 8m-urea on DEAE-cellulose. 3. Each chain was found to contain 15–18% glycine and significant amounts of the amino acids hydroxyproline and hydroxylysine. 4. By means of collagenase digestion it was shown that all three chains of rabbit subcomponent C1q contain collagen-like sequences of amino acids which constitute about 40% of each chain. 5. By use of carboxypeptidase A it was established, indirectly, that the collagen-like sequences, in one of the chains, are probably located near, or at, the N-terminal end of the chain. 6. Collagenase digestion and heating at 52°C (but not at 49°C) caused rapid loss of native rabbit subcomponent C1q haemolytic activity.

Targeting integrins: Insights into structure and activity of cyclic RGD pentapeptide mimics containing azabicycloalkane amino acids

2006 ◽  
Vol 14 (1) ◽  
pp. 169-180 ◽  
Author(s):  
Laura Belvisi ◽  
Anna Bernardi ◽  
Matteo Colombo ◽  
Leonardo Manzoni ◽  
Donatella Potenza ◽  
...  
Keyword(s):  
Amino Acids ◽  
Structure And Activity

scholarly journals Chromogenic Peptide Substrates for Kallikreins and Urokinase

1977 ◽  
Author(s):  
G. Claeson ◽  
S. Gustavsson ◽  
L. Aurell ◽  
G. Karlsson ◽  
P. Friberger
Keyword(s):  
Amino Acids ◽  
Plasma Kallikrein ◽  
Chromogenic Substrate ◽  
Trial And Error ◽  
Terminal Part ◽  
Peptide Substrates ◽  
Substrate Structure ◽  
Glandular Kallikrein ◽  
Structure And Activity

A chromogenic substrate for plasma kallikrein has been modelled after the amino acid sequence preceding one of the scissile bonds of kininogen, that is, the C-terminal part of bradykinin. Similar attempts to use the natural substrates as models for designing synthetic substrates for glandular kallikrein and urokinase have not been successful. However, by means of trial and error (variations of the amino acids in positions P1, P2 and P3) we have obtained correlations between substrate structure and activity. These correlations were then used to construct chromogenic peptide substrates for glandular kallikrein and urokinase.The new substrates have been utilized in methods for the determination of prekallikrein in plasma, kallikrein in urine and urokinase in urine respectively.

Homochirality as the Signature of Extra-Terrestrial Life

1997 ◽  
Vol 161 ◽  
pp. 505-510
Author(s):  
Alexandra J. MacDermott ◽  
Laurence D. Barron ◽  
Andrè Brack ◽  
Thomas Buhse ◽  
John R. Cronin ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Optical Rotation ◽  
Physical Origin ◽  
Natural Choice ◽  
Rosetta Mission ◽  
Terrestrial Life ◽  
Subsurface Layers ◽  
Solar System Bodies ◽  
Origin Of Homochirality

AbstractThe most characteristic hallmark of life is its homochirality: all biomolecules are usually of one hand, e.g. on Earth life uses only L-amino acids for protein synthesis and not their D mirror images. We therefore suggest that a search for extra-terrestrial life can be approached as a Search for Extra- Terrestrial Homochirality (SETH). The natural choice for a SETH instrument is optical rotation, and we describe a novel miniaturized space polarimeter, called the SETH Cigar, which could be used to detect optical rotation as the homochiral signature of life on other planets. Moving parts are avoided by replacing the normal rotating polarizer by multiple fixed polarizers at different angles as in the eye of the bee. We believe that homochirality may be found in the subsurface layers on Mars as a relic of extinct life, and on other solar system bodies as a sign of advanced pre-biotic chemistry. We discuss the chiral GC-MS planned for the Roland lander of the Rosetta mission to a comet and conclude with theories of the physical origin of homochirality.

Hydrogen Cyanide Polymers from the Impact of Comet P/Shoemaker-Levy 9 on Jupiter

1997 ◽  
Vol 161 ◽  
pp. 179-187
Author(s):  
Clifford N. Matthews ◽  
Rose A. Pesce-Rodriguez ◽  
Shirley A. Liebman
Keyword(s):  
Amino Acids ◽  
Solar System ◽  
Hydrogen Cyanide ◽  
Nitrogen Heterocycles ◽  
Laboratory Studies ◽  
Heterogeneous Solids ◽  
The Many ◽  
Comet Halley ◽  
The Impact ◽  
By Products

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.

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