scholarly journals The interaction of α-N-(p-toluenesulphonyl)-p-guanidino-L-phenylalanine methyl ester with thrombin and trypsin

1978 ◽  
Vol 169 (1) ◽  
pp. 157-167 ◽  
Author(s):  
Y S Klausner ◽  
M Rigbi ◽  
T Ticho ◽  
P J De Jong ◽  
E J Neginsky ◽  
...  
Keyword(s):  
Methyl Ester ◽  
Mixed Type ◽  
Peptide Inhibitors ◽  
Inhibition Constant ◽  
Inhibitor Concentration ◽  
Bovine Trypsin ◽  
Human Thrombin ◽  
Phenylalanine Methyl Ester ◽  
Esterase Activities

The syntheses are described of p-guanidino-L-phenylalanine and some of its derivatives. alpha-N-(p-Toluenesulphonyl)-p-guanidino-L-phenylalanine methyl ester is an excellent substrate of bovine trypsin (EC 3.4.21.4) (Km 57 micron; kcat. 320s-1 at pH 7.4-8.0) and a very poor substrate of human thrombin (EC 3.4.21.5) (Km 190 micron, kcat. 0.2s-1) and bovine chymotrypsin (EC 3.4.21.1). The ester inhibits thrombin clotting activity. It also inhibits the amidase and esterase activities of human thrombin, this inhibition being of the mixed type. The inhibition constant, K1, of the order of 1 micron, increases with increasing inhibitor concentration. This suggests that the enzyme binds the inhibitor at multiple sites. The importance of the residue at the P1 position [notation of Berger & Schechter (1970) Philos. Trans. R. Soc. London Ser. B 257, 249-264] in determining the selectivity of a substrate or quasi-substrate among trypsin-like enzymes is borne out. p-Guanidino-L-phenylalanine may have a use in the synthesis of selective peptide inhibitors of thrombin.

Assay of the Esterase Activity of Thrombin, Plasmin and Trypsin with a Chromogenic Substrate p-Nitrobenzyl p-Toluenesulfonyl-L-Arginine

1977 ◽  
Vol 37 (02) ◽  
pp. 253-261 ◽  
Author(s):  
Tadashi Aogaichi ◽  
Gerhard W. E Plaut
Keyword(s):  
Product Formation ◽  
Enzyme Concentration ◽  
Bovine Thrombin ◽  
Absorbance Change ◽  
Bovine Trypsin ◽  
Nitrobenzyl Alcohol ◽  
Human Thrombin ◽  
Hydrolysis Of ◽  
Ester Product ◽  
Esterase Activities

Summaryp-Nitrobenzyl p-toluenesulfonyl-L-arginine has been synthesized. A number of trypsin-like enzymes can catalyze the hydrolysis of this ester leading to formation of p-nitrobenzyl alcohol. After separation from the ester and p-toluenesulfonylarginine by extraction into chloroform, the p-nitrobenzyl alcohol liberated can be measured spectrophotometrically at 271 nm. Under the conditions of the assay, the hydrolysis of 1 μmol/ml of the ester is equivalent to an absorbance change of 4.45 cm–1 at 271 nm. With 0.10 mM p-nitrobenzyl p-toluenesulfonyl-L-arginine in 0.1 M Tris-HCl at pH 8.4 and 30°, the enzymatic hydrolysis is linearly proportional to time up to consumption of 60% of the ester. Product formation is proportional to enzyme concentration with 0.05 to 0.2 NIH clotting units/ml for bovine or human thrombin, 0.005 to 0.02 CTA units/ml for human plasmin, and 0.01 to 0.04 μg/ml protein for bovine pancreatic trypsin. In 0.1 M Tris-HCl at pH 8.4 and 30°, Kmis 14 μM and Vmax is 0.037 μmol/min/NIH unit/ml for bovine thrombin, Km is 78 μM and Vmax is 0.31 μmol/min/CTA unit/ml for human plasmin, and Km is 12 μM and Vmax is 138 μmol/min/mg protein/ml for bovine trypsin. With bovine thrombin, activities at pH 7.3 and at pH 9.2 were 30% lower and 40-50% higher than the rate at pH 8.4. Samples of bovine and human thrombin ranging in specific clotting activity from 59 to 2133 NIH units/mg protein showed esterase activities varying from 0.15 to 0.4 μmol p-nitrobenzyl alcohol formed/10 min/NIH unit.

Effects of the preparation method on the performance of the Cu/ZnO/Al2O3 catalyst for the manufacture of l-phenylalaninol with high ee selectivity from l-phenylalanine methyl ester

2014 ◽  
Vol 4 (4) ◽  
pp. 1132-1143 ◽  
Author(s):  
Zhangping Shi ◽  
Xiuzhen Xiao ◽  
Dongsen Mao ◽  
Guanzhong Lu
Keyword(s):  
Methyl Ester ◽  
Catalytic Hydrogenation ◽  
Preparation Method ◽  
Phenylalanine Methyl Ester ◽  
Al2o3 Catalyst

Efficient catalytic hydrogenation of l-phenylalanine methyl ester to l-phenylalaninol over the Cu/ZnO/Al2O3 catalyst with ~100% ee selectivity.

scholarly journals 4-fluorobenzylamine and phenylalanine methyl ester conjugates OF 2-nitroimidazole: Evaluation as hypoxic cell radiosensitizers

1992 ◽  
Vol 22 (3) ◽  
pp. 593-596 ◽  
Author(s):  
Pradeep K. Arg ◽  
Sudha Garg ◽  
William G. Degraff ◽  
Michael R. Zalutsky ◽  
James B. Mitchell
Keyword(s):  
Methyl Ester ◽  
Hypoxic Cell ◽  
Phenylalanine Methyl Ester

Synthesis of aspartame via asymmetric hydrogenation of N-protected (Z)-N-.alpha.-L-aspartyl-.DELTA.-phenylalanine methyl ester

1986 ◽  
Vol 51 (7) ◽  
pp. 1126-1128 ◽  
Author(s):  
Claudio Fuganti ◽  
Piero Grasselli ◽  
Luciana Malpezzi ◽  
Paolo Casati
Keyword(s):  
Methyl Ester ◽  
Asymmetric Hydrogenation ◽  
Phenylalanine Methyl Ester

scholarly journals New class of sensitive and selective fluorogenic substrates for serine proteinases. Amino acid and dipeptide derivatives of rhodamine

1983 ◽  
Vol 215 (2) ◽  
pp. 253-260 ◽  
Author(s):  
S P Leytus ◽  
W L Patterson ◽  
W F Mangel
Keyword(s):  
Amino Acid ◽  
Kinetic Constants ◽  
Amide Bond ◽  
Single Amino Acid ◽  
Amino Acid Derivative ◽  
Specific Substrate ◽  
Serine Proteinases ◽  
Bovine Trypsin ◽  
Human Thrombin ◽  
Derivatives Of

A series of dipeptide derivatives of Rhodamine, each containing an arginine residue in the P1 position and one of ten representative benzyloxycarbonyl (Cbz)-blocked amino acids in the P2 position, has been synthesized, purified and characterized as substrates for serine proteinases. These substrates are easily prepared with high yields. Cleavage of a single amide bond converts the non-fluorescent bisamide substrate into a highly fluorescent monoamide product. Macroscopic kinetic constants for the interaction of these substrates with bovine trypsin, human and dog plasmin, and human thrombin are reported. Certain of these substrates exhibit extremely large specificity constants. For example, the kcat./Km for bovine trypsin with bis-(N-benzyloxycarbonylglycyl-argininamido)-Rhodamine [(Cbz-Gly-Arg-NH)2-Rhodamine] is 1 670 000 M-1 X S-1. Certain of these substrates are also highly selective. For example, the most specific substrate for human plasmin, (Cbz-Phe-Arg-NH2)-Rhodamine, is not hydrolysed by human thrombin, and the most specific substrate for human thrombin, (Cbz-Pro-Arg-NH)2-Rhodamine, is one of the least specific substrates for human plasmin. Comparison of the kinetic constants for hydrolysis of the dipeptide substrates with that of the single amino acid derivative, (Cbz-Arg-NH)2-Rhodamine, indicates that selection of the proper amino acid residue in the P2 position can effect large increases in substrate specificity. This occurs primarily as a result of an increase in kcat. as opposed to a decrease in Km and, in certain cases, is accompanied by a large increase in selectivity. Because of their high degree of sensitivity and selectivity, these Rhodamine-based dipeptide compounds should be extremely useful substrates for studying serine proteinases.

Crystal-to-Crystal Diastereoselective Transformation of 2,4,6-Triisopropyl-4'-(S)-phenylalaninocarbonylbenzophenone Methyl Ester

1998 ◽  
Vol 54 (6) ◽  
pp. 907-911 ◽  
Author(s):  
H. Hosomi ◽  
Y. Ito ◽  
S. Ohba
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Methyl Ester ◽  
Absolute Configuration ◽  
Crystal Structure Analysis ◽  
X Ray Diffraction ◽  
Pass Filter ◽  
X Ray ◽  
Ultra High Pressure ◽  
Phenylalanine Methyl Ester

Dissymmetry of the photoproduct was induced by using a chiral substituent, (S)-methylphenylalanine, in the title compound {N-4-(2,4,6-triisopropylbenzoyl)benzoyl]-(S)-phenylalanine methyl ester (I)}. On irradiation with light from a 250 W ultra-high-pressure Hg lamp for 7 h through a long-pass filter, the photoreaction in a crystal was 100% complete without the loss of crystallinity. The crystal structures (I), before, and (II) {N-[4-(7-hydroxy-3,5-diisopropyl-8,8-dimethylbicyclo[4.2.0]octa-1,3,5-trien-7-yl)benzoyl]-(S)-phenylalanine methyl ester}, after photocyclization, have been determined by X-ray diffraction. For comparison, a crystal structure analysis has also been carried out for the photoproduct (III) of the 3′-COOMe derivative after recrystallization {methyl 3-(7-hydroxy-3,5-diisopropyl-8,8-dimethylbicyclo[4.2.0]octa-1,3,5-trien-7-yl)benzoate}. The dihedral angle between the central carbonyl plane and the triisopropylphenyl ring deviates from 90° by 10 (1)° in (I), which makes an imbalance in the intramolecular O(carbonyl)...H(methine) distances of the isopropyl groups at positions 2 and 6. The crystal structure of (II) indicates that the nearer methine H was predominantly abstracted by the carbonyl O atom in the reaction. The absolute configuration around the asymmetric C atom in the cyclobutenol ring of the product is S.

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