Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “dipeptides”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 721 records · Page 40Linked to original sources
PubMedDate not supplied

Investigation and determination of the antifibrinolytic properties of dipeptides and synthetic compounds.

1) Investigation and evaluation of antifibrinolytic activity of some new compounds has been carried out using two technics based, one on the "standard clots" method and the other one on labelled clots methods. 2) Among the first four members of the linear amino diacids 2-aminopimelic acid possesses a slight antifibrinolytic activity, the others are non active. 3) The two dipeptides having the same chain length as EACA behave differently ; beta alanyl-glycine is practically inactive whilst glycyl-beta alanine possesses a significant inhibiting power. The question is raised as to whether this active dipeptide might play an antifibrinolytic role in the organism. 4) Among the cyclic epsilon-amino acids tested, alpha aminocampholic acid and dl cis (2,2 dimethyl-3-alpha-aminoethyl) cyclobutaneacetic acid possess and activity slightly superior to that of EACA.

Amino Acids↗
PubMed1987

Hydrolysis of the brain dipeptide N-acetyl-L-aspartyl-L-glutamate. Identification and characterization of a novel N-acetylated alpha-linked acidic dipeptidase activity from rat brain.

High performance liquid chromatography studies documented the presence of an enzyme activity, N-acetylated alpha-linked acidic dipeptidase (NAALA dipeptidase), in rat brain membranes that cleaves the endogenous brain dipeptide, N-acetyl-L-aspartyl-L-glutamate to N-acetyl-aspartate and glutamate. With ion exchange chromatography, which quantitatively separated [3,4-3H]glutamate from N-acetyl-L-aspartyl-L-[3,4-3H]glutamate, we found that NAALA dipeptidase activity was essentially restricted to nervous tissue and kidney. We characterized NAALA dipeptidase activity in lysed synaptosomal membranes obtained from rat forebrain. Membrane-bound NAALA dipeptidase activity was optimal between pH 6.0 and 7.4 at 37 degrees C. Eadie-Hofstee analysis of kinetic data revealed a rather high apparent affinity for N-acetyl-L-aspartyl-L-glutamate with a Km = 540 nM and a Vmax = 180 nM/mg of protein/min. While NAALA dipeptidase showed a requirement for monovalent anions such as Cl-, the polyvalent anions phosphate and sulfate inhibited enzyme activity 50% at 100 microM and 1 mM, respectively. The divalent metal ion chelators EGTA, EDTA, and o-phenanthroline completely abolished activity, which was partially restored by manganese. Treatment of membranes with 1 mM dithiothreitol abolished NAALA dipeptidase activity. NAALA dipeptidase activity was also sensitive to the aminopeptidase inhibitors bestatin and puromycin, although not to the selective aminopeptidase A inhibitor amastatin. Structure-activity relationships inferred from inhibitor studies suggest that this enzyme shows specificity for N-acetylated alpha-linked acidic dipeptides. NAALA dipeptidase was also potently inhibited by the excitatory amino acid agonist L-quisqualate. Comparison of the properties of NAALA dipeptidase to those of previously characterized enzymes suggests that this is a novel peptidase which may be involved in the synaptic degradation of N-acetyl-L-aspartyl-L-glutamate.

Animals↗
PubMedDate not supplied

Behavioral effects of two dipeptides: L-phenylalanyl-L-arginine (Phe-L-Arg) and L-phenylalanyl-D-arginine (Phe-D-Arg) injected into the striatum or substantia nigra of rats.

Behavioral effects of two dipeptides: L-phenylalanyl-L-arginine (Phe-L-Arg) and L-phenylalanyl-D-arginine (Phe-D-Arg) on rat behavior after intrastriatal or intranigral injections were investigated. The L-L diastereoisomer of dipeptide (10-100 nmol) did not change the behavior while the L-D diastereoisomer induced clonic convulsions. Pretreatment by naloxone in a dose of 2 or 5 mg/kg prevented this effect. It is suggested that Phe-D-Arg might act via opioid receptors in nigrostriatal system.

Animals↗
PubMed1985

Synthesis and antimicrobial activity of some new isonicotinoylamino acid and dipeptide derivatives.

The synthesis of a series of isonicotinoylamino acids (II-XI) and some of their corresponding methyl esters (XII-XVIII), hydrazides (XXI-XXVI), dipeptide methyl esters (XXVII-XLII), the di- and tri-glycine peptides (XIX-XX) is described. Sixteen of various isonicotinoylamino acid and dipeptide derivatives were found to possess specific antimicrobial activities towards different microorganisms.

Amino Acid Sequence↗
PubMed1984

Inhibition of angiotensin-converting enzyme by dipeptide analogs.

Several dipeptide analogs containing an acyclic teritary amide group are effective angiotensin-converting enzyme (ACE) inhibitors with I50 values comparable to those of the best natural dipeptide inhibitors (e.g. Val-Trp). The most potent inhibitors studied feature a p-tolyl or norbornyl substituent on the amide nitrogen atom and a methyl or butylamino substituent on the carbon atom alpha to the amide group. REV 5277-R, alanyl-N-exo-norbornyl-glycine, is a competitive inhibitor of rabbit lung ACE with a Ki value of 9 microM.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1984

[Proteases from the enterocytes of the porcine small intestine. Role of aminopeptidase N in the transport of dipeptides].

The kinetics of radioactive label uptake from [U-14C]Gly, L-[4.5-3H]Leu and dipeptide [U-14C]Gly-L-[4.5-3H]Leu by the brush border membrane vesicles of porcine small intestine have been studied. The effect of aminopeptidase N inhibitors and of leucine-binding protein on the accumulation rates has been investigated. A comparison of the kinetic parameters for the uptake and hydrolysis of Gly-L-Leu, has demonstrated that the dipeptide transfer includes two conjugated steps, i. e., hydrolysis catalyzed by aminopeptidase N and transport of the resultant free amino acids by a specific carrier.

Aminopeptidases↗
PubMed1984

The immunomodulatory property of a novel synthetic compound adamantylamide dipeptide.

The adjuvant effect of a novel synthetic compound adamantylamide dipeptide (AdDP) was tested in a model of delayed hypersensitivity to ovalbumin in guinea pigs, and of immunostimulatory activity in the experiments with 3H thymidine where DNA biosynthesis was measured in several immunocompetent organs after administration of adamantylamide dipeptide. In both tests, the compound proved to be active since delayed hypersensitivity was potentiated and a marked increase in the utilization of 3H thymidine in liver, thymus and spleen has been observed. The novel compound appeared to be devoid of other effects of MDP such as pyrogenicity and arthritogenicity.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1984

Dipeptides delay the onset of morphine withdrawal in the mouse.

The effect of dipeptides was studied on naloxone-precipitated morphine withdrawal in the mouse. In accordance with previous data, s.c. treatment with Z-prolyl-D-leucine delayed the onset of withdrawal jumpings . Replacement of L-proline by L-glutamate or L-pyroglutamate resulted in dipeptides which were more potent in morphine withdrawal than was Z-prolyl-D-leucine.

Analysis of Variance↗
PubMedDate not supplied

[Enzymic splitting of polyurethanes containing dipeptide links in the main polymeric chain].

The paper deals with the proteolytic enzyme induced destruction of new types of segmented polyurethanes, the main chain of which contains dipeptides links: L-phenylalanyl-L-serine and glycyl-glycine. It is established that the chymotrypsin treatment decreases essentially the molecular mass of polyurethane containing the Phe--Ser links and does not affect the molecular mass of polyurethane with Gly--Gly links. Trypsin has no effect on the both types of polymers. Specificity of the chymotrypsin effect on the polymers is confirmed by the data of IR-spectroscopy. Destruction of the both types of segmented polyurethanes, mainly of the dipeptide fragments, is observed when the polymers are implanted into the animal organism.

Chymotrypsin↗
PubMedDate not supplied

[Effect of histidine analogs and histidyl-containing dipeptides on the decarboxylase activity of Micrococcus sp. n. histidine decarboxylase].

L-Histidinol and L-histidine hydroxamate were shown to inhibit competitively histidine decarboxylase from Micrococcus sp. n responsible for histamine biosynthesis. Constants of their inhibitory effect were found. Histidyl-containing dipeptides did not exhibit the pronounced inhibitory effect. The rate of inhibition was increased after esterification of histidyl dipeptide. Kinetics of the histidine decarboxylase inhibition by L-histidyl-L-leucine methyl ester was studied.

Carboxy-Lyases↗
PubMed1980

[Regulation of the processes of dipeptide and saccharose digestion and hexose absorption in the canine small intestine].

The total amount of digested saccharose increased under the effect of acetylcholine, noradrenaline, ornide, whereas the total amount of digested dipeptides increased under the effect of atropine. The decrease of the total amount of digested saccharose occurred under the effect of atropine and of digested dipeptides under the effect of acetylcholine, noradrenaline, ornide. The effects of these agents on digestion in the cavity and on the small intestine walls were not similar. The resorption of hexose formed during digestion of saccharose depended on the total amount of the digested saccharose.

Animals↗
PubMed1995

Identification of anthracenyl-dipeptide conjugates as novel topoisomerase I and II inhibitors and their evaluation as potential anticancer drugs.

As part of an ongoing rational drug design programme aiming to develop monosubstituted anthracenyl-peptides as potential anticancer drugs, three novel dipeptide conjugates have been synthesized and evaluated as inhibitors of topoisomerase (topo) I and II. Each of the three conjugates (designated NU/ICRF 600-602) was shown to inhibit the catalytic activity of both topoisomerase I and II, of which NU/ICRF 602 was the most active [100% inhibition of both enzymes at 5 micrograms/ml (approximately 15 microM) or less]. In a topo I/DNA unwinding assay, none of the compounds bound to DNA, suggesting genuine inhibition of catalytic activity. NU/ICRF 600 stabilized topo I cleavable complexes, although none of the compounds induced topo II-mediated DNA cleavage. Using a panel of Chinese hamster ovary cell lines along with the human ovarian cancer cell line, A2780, none of the three compounds were actively cytotoxic at concentrations < 100 microM. Subsequent drug uptake studies with NU/ICRF 600 and 602, using a method developed to correlate the chemosensitivity of A2780 cells with the uptake of anthracenyl-amino acid conjugates, revealed a lack of cellular uptake for both dipeptide conjugates. The significance of this finding in relation to drug design and the future development of this series of compounds is discussed.

Animals↗
PubMedDate not supplied

Localization of hydrolysis and transport of dipeptides in the mucosa of the small intestine (established on the basis of the anoxic criterion).

The influence of anoxia on the hydrolysis and transport of certain dipeptides by the rat small intestine in vitro was investigated. It was shown that in most cases, during anoxia there is virtually complete inhibition of active transport, whereas the hydrolysis of dipeptides, both by the intact intestine and by homogenates of the mucosa, is unchanged. These data suggest an important role of membrane hydrolysis at the concluding stages of peptide digestion in the small intestine. The interrelationship of the two types of peptide hydrolysis: membrane and intracellular, is discussed on the basis of the data obtained.

Aerobiosis↗
PubMed1995

[Interactions of various amino acids, dipeptides and glutathione with hypochlorite anion (CLO-)].

The specific features of interaction between sodium hypochlorite and various amino compounds were examined. It is shown that in the first reaction munite, methionine and glutathione are the most active in neutralizing hypochlorite anion, while histidine, glycine, alanine, dipeptides and taurine are less active. The chloroamino complexes formed by dipeptides and taurine are the most resistant.

Alanine↗
PubMed1993

Synthesis and benzodiazepine receptor affinity of N-(indol-3-ylglyoxylyl)-dipeptide derivatives. Structural requirements for inverse agonist/antagonist receptor interactions.

Several N-(indol-3-ylglyoxylyl)dipeptide derivatives 1-12 were synthesized and tested for their affinity at the benzodiazepine receptor in bovine cortical membranes. They proved to bind with low or no affinity at the receptor site. It was hypothesized that this result was not due to the steric hindrance of the dipeptide side chain, but to the establishment of intramolecular hydrogen bonds involving the indole N-H and/or the glyoxylyl C = O(2). Conformational analysis indicated that coiled conformations, with intramolecular hydrogen bonds, were energetically more favoured than the staggered, completely unfolded ones. Therefore, the low or no affinity of these compounds should be attributed to the unavailability of the N-H and/or C = O(2) groups for the binding, again confirming that both these groups are necessary for interaction with the receptor.

Animals↗
PubMed1993

Interleukin-1 beta converting enzyme. Synthesis of hydroxyethyl dipeptide surrogate-containing compounds as potential ICE inhibitors.

A series of compounds containing a hydroxyethyl-based dipeptide surrogate have been prepared as probes to evaluate the possibility of ICE being an aspartic protease. The aldehyde t-BocAsp(beta-t-butyl)H reacted with the organochromium species derived from phenethyl bromide and CrCl2 to give the expected addition product. Lactonization, reprotection of the amine and oxidation with RuCl3 gave the two protected dipeptide surrogates 7a and 7b. These were incorporated into tetra-, penta- and hexapeptide-like molecules and evaluated as inhibitors of the enzyme. The failure of these compounds to inhibit ICE indicated that this enzyme was very unlikely to be an aspartic protease.

Caspase 1↗
PubMedDate not supplied

[Thermodynamic and spectroscopic study of complex formation of dipeptides with dimethyl sulfoxide in their aqueous solutions].

Peculiarities of intermolecular interactions in water-dimethylsulfoxide solutions of dipeptides-glycyl-glycine, beta-alanyl-glycine, beta-alanyl-beta-alanine, DL-alpha-alanyl-DL-alpha-alanine, DL-alpha-alanyl-DL-valine-were analysed on the basis of thermodynamic characteristics and data on IR-spectra. Dimethylsulfoxide additions were shown to cause destruction of peptide associates present in aqueous solutions due to the formation of stronger bonds "peptide-DMSO". The existence of complexes between dimethylsulfoxide and beta-alanyl-glycine, beta-alanyl-beta-alanine, DL-alpha-alanyl-DL-alpha-alanine was found. The mechanism of their formation was determined by the dipeptide structure.

Dimethyl Sulfoxide↗