A convenient preparative method for tryptophan benzyl esters

1975 ◽  
Vol 28 (9) ◽  
pp. 2065 ◽  
Author(s):  
K Williams ◽  
B Halpern
Keyword(s):  
Amino Acid ◽  
Catalytic Hydrogenation ◽  
Synthetic Peptide ◽  
Preparative Method ◽  
Benzyl Ester ◽  
Protecting Groups ◽  
Benzyl Esters

The utilization of amino acid benzyl esters in synthetic peptide procedures offers advantages over the corresponding methyl or ethyl derivatives. Whereas the latter groups must by cleaved by alkaline saponification, the benzyl ester function can be removed by acidolysis or by catalytic hydrogenation under conditions which permit the simultaneous cleavage of N-acyl-protecting groups such as t-Boc or CBzl.*

scholarly journals E64 [trans-epoxysuccinyl-l-leucylamido-(4-guanidino)butane] analogues as inhibitors of cysteine proteinases: investigation of S2 subsite interactions

1994 ◽  
Vol 299 (2) ◽  
pp. 389-392 ◽  
Author(s):  
B J Gour-Salin ◽  
P Lachance ◽  
M C Magny ◽  
C Plouffe ◽  
R Ménard ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cathepsin B ◽  
Benzyl Ester ◽  
Amide Proton ◽  
Side Chain ◽  
Cysteine Proteinases ◽  
Enzyme Substrate ◽  
Amide Derivatives ◽  
Benzyl Esters ◽  
S2 Subsite

A number of epoxysuccinyl amino acid benzyl esters (HO-Eps-AA-OBzl) and benzyl amides (HO-Eps-AA-NHBzl) (where AA represents amino acid) were synthesized as analogues of E64, a naturally occurring inhibitor of cysteine proteinases. These inhibitors were designed to evaluate if selectivity for cathepsin B could be achieved by varying the amino acid on the basis of known substrate specificity. Contrary to the situation with substrates, it was found that variation of the amino acid in the E64 analogues does not lead to major changes in the kinetic parameter kinac./Ki and that the specificity of these analogues does not parallel that observed for substrates. This is particularly true in the case of the benzyl ester derivatives where the deviation from substrate-like behaviour is more important than with the benzyl amide derivatives. The results suggest that the amide proton of the benzyl amide group in HO-Eps-AA-NHBzl interacts in the S2 subsite in both cathepsin B and papain and contributes to increase the potency of these inhibitors. The kinetic data also suggest that differences in the orientation of the C alpha-C beta bond of the side chain in the S2 subsite of the enzyme might explain the differences between substrate and E64 analogue specificities. This hypothesis is supported by the fact that the order of inactivation rates with chloromethane inhibitors (which are believed to be good models of enzyme-substrate interactions) is indeed very similar to that observed with the corresponding amidomethylcoumarin substrates. In conclusion, the information available from S2-P2 interactions with substrates cannot be used to enhance the selectivity of the E64 analogues in a rational manner.

scholarly journals Crystal structure of Boc-(S)-ABOC-(S)-Ala-(S)-ABOC-(S)-Phe-OBn chloroform monosolvate

2015 ◽  
Vol 71 (10) ◽  
pp. 1193-1195
Author(s):  
Emmanuel Wenger ◽  
Laure Moulat ◽  
Baptiste Legrand ◽  
Muriel Amblard ◽  
Monique Calmès ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Amino Acid ◽  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Benzyl Ester ◽  
Protecting Groups ◽  
Amino Acid Residues ◽  
Hybrid Peptide ◽  
Proteinogenic Amino Acid ◽  
Solvent Molecules

In the title compound, phenyl (S)-2-[(S)-(1-{2-[(S)-(1-{[(tert-butoxy)carbonyl]amino}bicyclo[2.2.2]octan-2-yl)formamido]propanamido}bicyclo[2.2.2]octan-2-yl)formamido]-3-phenylpropanoate chloroform monosolvate, C42H56N4O7·CHCl3, the α,β-hybrid peptide contains two non-proteinogenic amino acid residues of (S)-1-aminobicyclo[2.2.2]octane-2-carboxylic acid [(S)-ABOC], two amino acid residues of (S)-2-aminopropanoic acid [(S)-Ala] and (S)-2-amino-3-phenylpropanoic acid [(S)-Phe], and protecting groups oftert-butoxycarbonyl (Boc) and benzyl ester (OBn). The tetramer folds into a right-handed mixed 11/9 helix stabilized by intramoleculari,i + 3 andi,i − 1 C=O...H—N hydrogen bonds. In the crystal, the oligomers are linked by N—H...O=C hydrogen bonds into chains along thea-axis direction. The chloroform solvent molecules are intercalated between the folded chainsviaC—H...O=C interactions.

The preparation of dimedone derivatives of amino acids and their use in peptide synthesis

1965 ◽  
Vol 18 (3) ◽  
pp. 417 ◽  
Author(s):  
B Halpern
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Peptide Synthesis ◽  
Catalytic Hydrogenation ◽  
Amino Acid Derivatives ◽  
Alkyl Esters ◽  
Benzyl Esters ◽  
Derivatives Of

The preparation of dimedone derivatives of amino acids has been effected by saponification of the corresponding alkyl esters, and also by catalytic hydrogenation of the respective benzyl esters. The amino acid derivatives have been used to synthesize peptides in excellent yields, employing dicyclohexyl carbodiimide as the condensing agent.

Detection of fos protein during osteogenesis by monoclonal antibodies

1988 ◽  
Vol 8 (5) ◽  
pp. 2251-2256
Author(s):  
P De Togni ◽  
H Niman ◽  
V Raymond ◽  
P Sawchenko ◽  
I M Verma
Keyword(s):  
Monoclonal Antibodies ◽  
Amino Acid ◽  
Indirect Immunofluorescence ◽  
Protein Complex ◽  
Synthetic Peptide ◽  
Immunohistochemical Staining ◽  
Nuclear Staining ◽  
Rat Embryos ◽  
Fos Protein ◽  
Modified Forms

We have generated monoclonal antibodies by using a synthetic peptide corresponding to amino acid positions 4 to 17 of the human fos protein. The antibodies detected both v- and c-fos proteins by immunoprecipitation, immunoblotting, and indirect immunofluorescence. The monoclonal antibodies not only identified the fos protein complex with the cellular 39-kilodalton protein, but also recognized the modified forms of the mouse, rat, and human fos proteins. In day-17 rat embryos, nuclear-staining fos protein could be identified in the cartilage by immunohistochemical staining.

Comparative effects of L-NNA and alkyl esters of L-NNA on pulmonary vasodilator responses to ACh, BK, and SP

1994 ◽  
Vol 266 (6) ◽  
pp. H2416-H2422 ◽  
Author(s):  
D. Y. Cheng ◽  
B. J. DeWitt ◽  
T. J. McMahon ◽  
P. J. Kadowitz
Keyword(s):  
Substance P ◽  
Vagal Stimulation ◽  
Benzyl Ester ◽  
No Synthase ◽  
Flow Conditions ◽  
Inhibitory Effects ◽  
Vascular Bed ◽  
Pulmonary Vasodilator ◽  
Benzyl Esters ◽  
Pulmonary Vascular Bed

The comparative effects of the nitric oxide (NO) synthase inhibitors N omega-nitro-L-arginine (L-NNA), N omega-nitro-L-arginine methyl ester (L-NAME), and N omega-nitro-L-arginine benzyl ester (L-NABE) on baseline tone and on vasodilator responses to acetylcholine (ACh), bradykinin (BK), and substance P (SP) were compared in the pulmonary vascular bed of the cat under constant flow conditions. After administration of the NO synthase inhibitors in intravenous doses of 100 mg/kg, the increase in lobar arterial pressure and the attenuation of vasodilator responses to ACh, BK, and SP were similar, whereas responses to adenosine and felodipine, endothelium-independent vasodilator agents, were not altered. In addition to inhibiting responses to ACh, BK, and substance P, the NO synthase inhibitors enhanced vasodilator responses to S-nitroso-N-acetylpenicillamine and NO. Moreover, atropine inhibited pulmonary vasodilator responses to ACh but not to SP or BK, and L-NAME or L-NABE had no effect on the decrease in heart rate in response to efferent vagal stimulation, a muscarinic receptor-mediated response that is independent of NO release. The similar inhibitory effects of L-NNA, L-NAME, and L-NABE on vasodilator responses to ACh, BK, and SP suggest that the L-arginine analogue, L-NNA, as well as the methyl and benzyl esters of L-NNA are useful probes for studying NO-mediated endothelium-dependent responses in the pulmonary vascular bed of the intact-chest cat.(ABSTRACT TRUNCATED AT 250 WORDS)

Preparation and some biological properties of N-acetylmuramyl-alanyl-D-isoglutamine (MDP) analogues

1982 ◽  
Vol 47 (11) ◽  
pp. 2989-2995 ◽  
Author(s):  
Milan Zaoral ◽  
Jan Ježek ◽  
Jiří Rotta
Keyword(s):  
Biological Properties ◽  
Benzyl Ester ◽  
Protecting Groups

The condensation of 1-α-O-benzyl-4,6-O-benzylidene-N-acetylgalactomuramic acid (I), 1-α-O-benzyl-4,6-O-benzylidene-N-acetylallomuramic acid (VIII), and 1-α-O-benzyl-4,6-O-benzylidene-N-acetylnorallomuramic acid (XI) with alanyl-D-isoglutamine benzyl ester afforded 1-α-O-benzyl-4,6-O-benzylidene-N-acetylgalactomuramyl-alanyl-D-isoglutamine benzyl ester (XII), 1-α-O-benzyl-4,6-O-benzylidene-N-acetylallomuramyl-alanyl-D-isoglutamine benzyl ester (XIII) and 1-α-O-benzyl-4,6-O-benzylidene-N-acetylnorallomuramyl-alanyl-D-isoglutamine benzyl ester (XIV). Protecting groups were removed from XII-XIV and N-acetylgalactomuramyl-alanyl-D-isoglutamine (XV), N-acetylallomuramyl-alanyl-D-isoglutamine (XVI), and N-acetylnorallomuramyl-alanyl-D-isoglutamine (XVII) were obtained. XV-XVII showed lower pyrogenic and immunoadjuvant effect than N-acetylmuramyl-alanyl-D-isoglutamine.

scholarly journals The heparin–protein complex of ox liver capsule. Isolation and chemical characterization

1969 ◽  
Vol 112 (2) ◽  
pp. 167-172 ◽  
Author(s):  
A Serafini-Fracassini ◽  
J J Durward ◽  
L. Floreani
Keyword(s):  
Amino Acid ◽  
Column Chromatography ◽  
Catalytic Hydrogenation ◽  
Protein Complex ◽  
Amino Acid Analysis ◽  
Chemical Characterization ◽  
Isolation And Purification ◽  
Liver Capsule ◽  
Heparin Fractions ◽  
Good Agreement

1. A procedure for the isolation and purification of the heparin–protein complex from ox liver capsule, based on the solubility properties of mucopolysaccharide–cetylpyridinium complexes, is described. 2. The yield of the heparin–protein complex with this method averages 35mg./100g. of dry ox liver capsule. 3. The results of analyses on the polysaccharide show good agreement with values previously published for purified heparin fractions. 4. The amino acid analysis of the protein component shows several similarities to that of chondromucoprotein. 5. The results of β-carbonyl elimination, either with or without catalytic hydrogenation, and column chromatography after β-elimination, show that the polysaccharide is covalently bound to the protein.

A SYNTHETIC PEPTIDE FOR EVALUATING PROTEIN SEQUENCER AND AMINO ACID ANALYZER PERFORMANCE IN CORE FACILITIES: DESIGN AND RESULTS

1989 ◽  
pp. 89-101 ◽  
Author(s):  
Ronald L. Niece ◽  
Kenneth R. Williams ◽  
Cynthia L. Wadsworth ◽  
James Elliott ◽  
Kathryn L. Stone ◽  
...  
Keyword(s):  
Amino Acid ◽  
Synthetic Peptide ◽  
Amino Acid Analyzer ◽  
Facilities Design ◽  
Protein Sequencer ◽  
Core Facilities
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