Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The synthesis of the protected duopentacontapeptide corresponding to the entire amino acid sequence I-52 of porcine pancreatic secretory trypsin inhibitor II (Kazal type) is described. The benzyloxycarbonyltetradecapeptide tert-butyloxycarbonylhydrazide (sequence 1-14) was selectively deblocked with trifluoroacetic acid and used to acylate, by the azide procedure, the peptide free base corresponding to the sequence 15-52. The isolated material was purified by ion exchange chromatography and the protecting groups were removed by successive treatments with anhydrous hydrogen fluoride, 1 M piperidine and mercuric acetate. F02M phosphate buffer, pH8. Determination of the inhibitory capacity indicated that the synthetic material is about 50% effective, at 30:1 inhibitor:trypsin molar ratio in inhibiting the tryptic hydrolysis of Nalpha-benzoyl-DL-arginine-4-nitroanilide. Full inhibition was achieved at a higher inhibitor:trypsin molar ratio. The stability constants and the standard free energy of binding of the complex between trypsin and the synthetic inhibitor have been determined.
...
PMID:Studies on trypsin inhibitors. Part IX. Synthesis and trypsin inhibitory activity of the duopentacontapeptide corresponding to the amino acid sequence of porcine pancreatic secretory trypsin inhibitor II (Kazal). 4 25

The synthetic thrombin-inhibitor termed No. 205 (N-alpha-dansyl-L-arginine-4-ethyl-piperidine amide) found in our laboratories was studied kinetically using synthetic peptide substrates. The following results were obtained. 1. No. 205 inhibited thrombin competively with bz-Phe-Val-Arg-pNA and the Ki value obtained was extremely small, 3.7 x 10(-8) M. 2. No. 205 also inhibited trypsin competitively with bz-Phe-Val-Arg-pNA but the Ki value obtained was far larger than that for thrombin, 1.0 x 10(-5) M. 3. No. 205 inhibited F. Xa, plasmin and urokinase only to a small extent when estimated using 2 x 10(-4) M D-Val-Leu-Lys-pNA, bz-Ile-Glu-Gly-Arg-pNA and Glu-Gly-Arg-pNA, respectively. 4. No 205 differed from APPA in its specific inhibitory spectrum for thrombin as compared to trypsin, plasmin and F. Xa. The above results indicate that No. 205 is an extremely potent and highly selective reversible thrombin-inhibitor.
...
PMID:Kinetic studies on the selectivity of a synthetic thrombin-inhibitor using synthetic peptide substrates. 15 13

Trypsin and trypsin-like enzymes cleave C-terminal bonds of the basic amino acids Arg and Lys. Inhibitors of these enzymes have been found not only among Arg and Lys derivatives but also with structurally related benzamidines. Especially cyclic amides of 4-amidinophenylalanine were found to be inhibitors of thrombin. The most potent selective thrombin inhibitor of these type is N alpha-(beta-naphthylsulfonylglycyl)-4-amidinophenylalanine piperidine. From the X-ray crystal structures of thrombin and trypsin-inhibitor complexes the thrombin complexes formed with inhibitors derived from amidinophenylalanine have been modeled. These models allow valuable predictions to design inhibitors of improved selection and binding properties. Most recently, also the X-ray crystal structures of complexes of inhibitors with bovine thrombin have been solved.
...
PMID:Interactions of thrombin with benzamidine-based inhibitors. 151 80

The X-ray crystal structures of the complexes formed with bovine trypsin and the N alpha-tosylated piperidides of m-amidino-, p-amidino- and p-guanidino-D,L-phenylalanine (3-TAPAP, 4-TAPAP and 4-TGPAP) were determined with data to 1.8 A resolution. The L-stereoisomer of 3-TAPAP binds as a compact entity into the active site of trypsin, with the amidino and the carbonyl groups of the central amidinophenylalanyl residue hydrogen-bonded to Gly216 of trypsin. According to modeling and energy minimization, 3-TAPAP fits perfectly in this conformation to the more restrictive thrombin active site also (Bajusz et al. (1978) Int. J. Pept. Prot. Res. 12, 217-221); the piperidine moiety extends into the cage-like S2 subsite of thrombin, but leaves room for additional substituents which might help to improve binding and pharmacological properties. In contrast, 4-TAPAP and 4-TGPAP bind only weakly and in an extended conformation to trypsin; their considerably enhanced affinities for thrombin would suggest a more compact binding to thrombin.
...
PMID:Geometry of binding of the N alpha-tosylated piperidides of m-amidino-, p-amidino- and p-guanidino phenylalanine to thrombin and trypsin. X-ray crystal structures of their trypsin complexes and modeling of their thrombin complexes. 187 20

An opioid nonapeptide was isolated from fresh frozen human pituitaries. Its primary structure (Leu-Val-Tyr-Pro-Trp-Thr-Gln-Arg) was identical to fragment 32-40 of the beta-, delta-, gamma- and epsilon-chains of human hemoglobin. A larger peptide of about 4.5 kDa, which generated a fragment containing the nonapeptide on trypsin digestion, showed an amino acid composition similar to fragment 1-41 of the beta-chain of human hemoglobin. The nonapeptide interacted with mu-opioid receptors in rat brain homogenates using [3H]-(D-Ala2, MePhe3, Gly-ol5)-enkephalin and with sigma-receptors using (+)-[3H]-3-(3-hydroxyphenyl)-N-1-(propyl)piperidine, respectively. The affinities for mu-opioid receptors were in the same range as those observed for the structurally related beta-casomorphins. However, the isolated peptide showed markedly higher affinity at sigma-binding sites when compared to the beta-casomorphins or other opioid peptides. The opioid potency of this peptide as determined in the guinea-pig ileum myenteric plexus muscle preparation, was significant but less than that observed for the beta-casomorphins.
...
PMID:Isolation and characterization of a hemoglobin-derived opioid peptide from the human pituitary gland. 192 87

The X-ray crystal structure of the trypsin complex formed with N alpha-(2-naphthyl-sulphonyl-glycyl)-DL-p-amidinophenylalanyl-piper idine (NAPAP) was determined with X-ray data to 0.18-nm resolution and crystallographically refined. NAPAP binds into the active site of trypsin in a quite compact form: the p-amidinophenylalanine moiety of the D-stereoisomer binds into the specificity pocket; the glycyl group is hydrogen bonded with Gly216; the naphthyl group stands perpendicular to the indole moiety of Trp215; the piperidine ring is tightly packed between this naphthyl moiety and His57; in consequence the carboxy-terminal amido bond of NAPAP is located in such a way that it is not susceptible to the active-site Ser195. NAPAP and (2R,4R)-4-methyl-1-[N alpha-(3-methyl-1,2,3,4-tetrahydro-8- quinolinesulphonyl)-L-arginyl]-2-piperidine carboxylic acid (MQPA) [Matzusaki, T., Sasaki, C., Okumura, C. & Umeyama (1989) J. Biochem. (Tokyo) 105, 949-952] were transferred in their trypsin-binding conformations to human alpha-thrombin [Bode, W., Mayr, I., Baumann, U., Huber, R., Stone, S. R. & Hofsteenge, J. (1989) EMBO J. 8. 3467 - 3475] and energy minimized. Both synthetic inhibitors fit perfectly into the much more restricted active site of thrombin. The accommodation of the S-aryl moieties in the 'aryl-binding site' and of the piperidine rings in the S2 subsite of thrombin are particularly favorable. The preference of thrombin for distinctly substituted piperidine derivatives and its generally higher (compared with trypsin) affinity for benzamidine and arginine-based inhibitors can be accounted for by these thrombin inhibitor models.
...
PMID:Geometry of binding of the benzamidine- and arginine-based inhibitors N alpha-(2-naphthyl-sulphonyl-glycyl)-DL-p-amidinophenylalanyl-pipe ridine (NAPAP) and (2R,4R)-4-methyl-1-[N alpha-(3-methyl-1,2,3,4-tetrahydro-8- quinolinesulphonyl)-L-arginyl]-2-piperidine carboxylic acid (MQPA) to human alpha-thrombin. X-ray crystallographic determination of the NAPAP-trypsin complex and modeling of NAPAP-thrombin and MQPA-thrombin. 222 34

Restriction fragments of bacteriophage phi 29 DNA-gp3 (DNA-gene product 3 complex) were packaged in a completely defined in vitro system that included purified proheads, the DNA packaging protein gp16 and ATP. Both left and right end DNA-gp3 fragments were packaged in this system, in contrast to the oriented and selective packaging of left end DNA-gp3 fragments in extracts; left ends could be packaged quantitatively in the defined system, while the packaging efficiency of right ends was generally about threefold lower. In addition, certain internal (non-end) DNA fragments were packaged at efficiencies of about 10% to 15%. Digestion of the gp3 with trypsin or proteinase K reduced the packaging of whole-length DNA by a factor of 2 or 4, respectively, and removal of the gp3 from whole-length DNA or end fragments with piperidine reduced packaging to the level of internal fragments. Though the terminal protein gp3 was non-essential for DNA translocation in the defined system, it stimulated packaging of left and right end fragments, and stabilized packaging of the left end. The packaging of end and internal DNA fragments of the related phage M2Y into phi 29 proheads was similar to that of phi 29 DNA fragments, and certain fragments of lambda DNA were packaged at the efficiency of the internal phi 29 DNA fragments. Selective packaging of DNA-gp3 left ends was restored by the addition of bacterial cell extracts or glycerol to the defined system, and these packaging conditions discriminated between phi 29 and M2Y DNAs that have distinct terminal proteins.
...
PMID:In vitro packaging of bacteriophage phi 29 DNA restriction fragments and the role of the terminal protein gp3. 253 Mar 57

The relationship between chemical modifications of arginine derivatives and inhibitory activity to trypsin, plasmin and glandular kallikrein was investigated comparing with that of thrombin and concluded as follows: The hydrophobic binding pocket, which has been reported previously to be stereogeometrically very similar in trypsin and thrombin, corresponded to the length of ethylpiperidine. Concerning the site (termed the P site) next to the hydrophobic binding pocket, there were large differences in stereogeometry between trypsin and thrombin; the binding site of trypsin extended further to allow propyl and phenyl group attached to piperidine, while that of thrombin would be much narrower and unable to allow them. The P sites of plasmin and glandular kallikrein resembled that of trypsin in being able to allow phenyl group. To substantialize the hydrophobic binding pocket and the P site, a (2R, 4R)-MQPA-trypsin complex model was generated using the results of X-ray crystallography of (2R, 4R)-MQPA and BPTI-trypsin complex by calculation to minimize van der Waals contacts, and it was of great use for understanding the geometry of the active sites of trypsin, thrombin, plasmin and glandular kallikrein.
...
PMID:Similarity and dissimilarity in the stereogeometry of the active sites of thrombin, trypsin, plasmin and glandular kallikrein. 295 62

The relationship between chemical modifications of arginine derivatives and inhibitory activity to horse serum cholinesterase (BuChE) was investigated. It provided a new insight into the topography of the active site of BuChE. 1) BuChE has the hydrophobic binding pocket, the depth of which corresponds to the length of ethylpiperidine. 2) In the opposite side to the hydrophobic binding pocket, BuChE has a certain entity which repulses carboxyl group at the 2-position of piperidine of L-arginine piperidine amide. 3) The P site of BuChE can allow 4-propyl and 4-phenyl group attached to piperidine. Comparison of the results with those of thrombin and trypsin clearly revealed similarities and dissimilarities among BuChE, trypsin, and thrombin in the active site topography, and hence, we introduce a new selective inhibitor for BuChE, N alpha-dansyl-L-arginine 4-phenylpiperidine amide. It inhibits BuChE strongly (Ki = 0.016 microM), whereas it inhibits trypsin, thrombin, plasmin, and glandular kallikrein only weakly and shows actually no inhibition on acetylcholinesterase from the human erythrocyte. In addition, the new inhibitor becomes highly fluorescent when bound with BuChE, indicating that the compound is an ideal probe of the interactions of BuChE as well as a titrant of it.
...
PMID:N alpha-dansyl-L-arginine 4-phenylpiperidine amide. A potent and selective inhibitor of horse serum cholinesterase. 340 26

Two analogs of porcine insulin with substitutions of leucine for phenylalanine in the COOH-terminal region of the insulin B chain have been prepared by a combination of solid-phase synthesis and semisynthesis. Solid-phase synthesis of the substituted octapeptides B23-B30 bearing the trifluoracetyl group on lysine-B29, enzymatic coupling of the octapeptides to bis(tertiary-butyloxycarbonyl)desoctapeptide insulin by trypsin, and deprotection of the corresponding adducts in formic acid and piperidine resulted in two insulin derivatives, one with leucine at position B24 and the other with leucine at position B25. These analogs had only about 10% and 1%, respectively, of the activity of porcine insulin in competing for the binding of [125I]iodoinsulin to both rat adipocytes and human IM-9 lymphocytes. The relative potencies of the analogs in stimulating glucose oxidation by rat adipocytes decreased in the order porcine insulin > [LeuB24]insulin > [LeuB25]insulin. However, at high concentrations both analogs had full agonists activity. Experiments in which the semisynthetic insulins were mixed with the native hormone showed that [LeuB24]insulin, but not [LeuB25]insulin, was an active antagonist of insulin action. These results suggest that the antagonistic activity of a human insulin variant having leucine at position B24 or B25 can be assigned to the molecule with the sequence Gly-Leu-Phe-Tyr (residues B23-B26) in its active site.
...
PMID:Semisynthesis and biological activity of porcine [LeuB24]insulin and [LeuB25]insulin. 699 72


1 2 3 Next >>

---