Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 22
Filter
Add more filters










Publication year range
1.
Neotrop. ichthyol ; 17(1): e180161, 2019. graf
Article in English | VETINDEX, LILACS | ID: biblio-1002712

ABSTRACT

Wolf cichlid, Parachromis dovii, is a species with a high potential for aquaculture in Central America; however, the knowledge of the digestive physiology in larvae period is limited. For these reason, this study evaluated the changes on digestive enzymes (alkaline and acid proteases, trypsin, chymotrypsin, aminopeptidase, carboxypeptidase, lipases, amylases, and phosphatases) during early ontogeny by biochemical analysis. All digestive enzymes were detected at first feeding (6 days after hatching, DAH, 9.49 mm, 168 degree-days DD). Afterwards all enzymes reached two main peaks in activity at 14 or 22 DAH (15.10 mm, 364 DD and 20.83 mm, 550 DD, respectively). Later, there was a gradual decrease in activity for trypsin and acid and alkaline phosphatases until reach the lowest values at 41 DAH. In the case of acid proteases, chymotrypsin, aminopeptidase, carboxypeptidase, lipase and amylase, all activities reached their maximum values at the end of the larval period, except for alkaline proteases, which showed the maximum value at 14 DAH (15.10 mm, 364 DD). Parachromis dovii larvae have an early capability to hydrolyze exogenous food, agreeing with other carnivorous neotropical cichlid species, for this reason we proposed that the weaning process could begin at 14 DAH.(AU)


El guapote lagunero (Parachromis dovii) es una especie con un alto potencial para la acuicultura en la región de América Central; sin embargo, existe un conocimiento limitado sobre la capacidad digestiva en el periodo larval. Por este motivo, este estudio evaluó los cambios de las enzimas digestivas (proteasas alcalinas y ácidas, tripsina, quimotripsina, aminopeptidasa, carboxipeptidasa, lipasas, amilasas y fosfatasas) durante la ontogenia temprana mediante análisis bioquímico. Todas las enzimas digestivas analizadas se detectaron en la primera alimentación (6 días después de la eclosión, DAH, 9.49 mm, 168 día-grados DD). Después, todas las enzimas alcanzaron dos picos máximos a los 14 o 22 DAH (15.10 mm, 364 DD and 20.83 mm, 550 DD, respectivamente). Después las actividades tripsina, fosfatasas ácidas y alcalina disminuyeron a sus valores más bajos a los 41 DAH. En el caso de las proteasas ácidas y alcalinas, quimotripsina, aminopeptidasa, carboxipeptidasa, lipasa y amilasa, los niveles de actividad aumentaron y alcanzaron su máximo valor al final del período larvario, excepto las proteasas alcalinas, que mostraron su máximo valor a los 14 DAH (15.10 mm, 364 DD). Las larvas de P. dovii tienen una capacidad temprana para hidrolizar alimentos exógenos, lo que concuerda con otras especies de cíclidos neotropicales carnívoros, por lo que proponemos que el proceso de destete inicie a los 14 DAH.(AU)


Subject(s)
Animals , Peptide Hydrolases/chemical synthesis , Cichlids/physiology , Enzyme Activation , Aquaculture
2.
Metallomics ; 8(11): 1159-1169, 2016 11 09.
Article in English | MEDLINE | ID: mdl-27714031

ABSTRACT

The accidental discovery of cisplatin some 50 years ago generated renewed interest in metallopharmaceuticals. Beyond cisplatin, many useful metallodrugs have been synthesized for the diagnosis and treatment of various diseases, but toxicity concerns, and the propensity to induce chemoresistance and secondary cancers make it imperative to search for novel metallodrugs that address these limitations. The Amino Terminal Cu(ii) and Ni(ii) (ATCUN) binding motif has emerged as a suitable template to design catalytic metallodrugs with nuclease and protease activities. Unlike their classical counterparts, ATCUN-based metallodrugs exhibit low toxicity, employ novel mechanisms to irreversibly inactivate disease-associated genes or proteins providing in principle, a channel to circumvent the rapid emergence of chemoresistance. The ATCUN motif thus presents novel strategies for the treatment of many diseases including cancers, HIV and infections caused by drug-resistant bacteria at the genetic level. This review discusses their design, mechanisms of action and potential for further development to expand their scope of application.


Subject(s)
Anti-Infective Agents/chemistry , Antineoplastic Agents/chemistry , Drug Design , Organometallic Compounds/chemistry , Anti-Infective Agents/chemical synthesis , Antineoplastic Agents/chemical synthesis , Catalysis , Drug Resistance, Microbial , Esterases/chemical synthesis , Esterases/chemistry , Humans , Organometallic Compounds/chemical synthesis , Peptide Hydrolases/chemical synthesis , Peptide Hydrolases/chemistry
3.
Bioresour Technol ; 222: 210-216, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27718403

ABSTRACT

The use of processes for simultaneous production of bioproducts as enzymes and bioactive compounds is an interesting alternative to reduce environmental impacts. Thus, the aim of this study was to produce simultaneously, using the biorefinery concept, both proteases and bioactive compounds with antioxidant activity from Bacillus sp. P45 cultivation by using different by-products. The integrated process developed in this study enabled to obtain enzymes with proteolytic and keratinolytic properties in a process with alternate substrates from agro-industrial by-products (feather meal, residual feather meal and biomass), thus, creating an interesting alternative to managing them. The residual biomass provided the highest protease activity (1306.6U/mL) and the reused feather meal reached the highest keratinolytic activity (89U/mL), both at 32h of cultivation. Moreover, hydrolysates produced in cultivation using feather meal and residual biomass had high antioxidant activity, they have great potential as natural antioxidants.


Subject(s)
Agrochemicals/chemistry , Antioxidants/chemical synthesis , Industrial Waste , Peptide Hydrolases/chemical synthesis , Animals , Bacillus/metabolism , Biomass , Peptide Hydrolases/chemistry
4.
Braz J Med Biol Res ; 46(6): 465-85, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23828584

ABSTRACT

Most drugs function by binding reversibly to specific biological targets, and therapeutic effects generally require saturation of these targets. One means of decreasing required drug concentrations is incorporation of reactive metal centers that elicit irreversible modification of targets. A common approach has been the design of artificial proteases/nucleases containing metal centers capable of hydrolyzing targeted proteins or nucleic acids. However, these hydrolytic catalysts typically provide relatively low rate constants for target inactivation. Recently, various catalysts were synthesized that use oxidative mechanisms to selectively cleave/inactivate therapeutic targets, including HIV RRE RNA or angiotensin converting enzyme (ACE). These oxidative mechanisms, which typically involve reactive oxygen species (ROS), provide access to comparatively high rate constants for target inactivation. Target-binding affinity, co-reactant selectivity, reduction potential, coordination unsaturation, ROS products (metal-associated vs metal-dissociated; hydroxyl vs superoxide), and multiple-turnover redox chemistry were studied for each catalyst, and these parameters were related to the efficiency, selectivity, and mechanism(s) of inactivation/cleavage of the corresponding target for each catalyst. Important factors for future oxidative catalyst development are 1) positioning of catalyst reduction potential and redox reactivity to match the physiological environment of use, 2) maintenance of catalyst stability by use of chelates with either high denticity or other means of stabilization, such as the square planar geometric stabilization of Ni- and Cu-ATCUN complexes, 3) optimal rate of inactivation of targets relative to the rate of generation of diffusible ROS, 4) targeting and linker domains that afford better control of catalyst orientation, and 5) general bio-availability and drug delivery requirements.


Subject(s)
Coordination Complexes/pharmacokinetics , Molecular Targeted Therapy/methods , Peptide Hydrolases/pharmacokinetics , Reactive Oxygen Species/pharmacology , Biological Availability , Catalysis , Genes, env , Humans , Oxidation-Reduction , Peptide Hydrolases/chemical synthesis , Peptidyl-Dipeptidase A/metabolism
5.
Braz. j. med. biol. res ; 46(6): 465-485, 02/jul. 2013. tab, graf
Article in English | LILACS | ID: lil-679202

ABSTRACT

Most drugs function by binding reversibly to specific biological targets, and therapeutic effects generally require saturation of these targets. One means of decreasing required drug concentrations is incorporation of reactive metal centers that elicit irreversible modification of targets. A common approach has been the design of artificial proteases/nucleases containing metal centers capable of hydrolyzing targeted proteins or nucleic acids. However, these hydrolytic catalysts typically provide relatively low rate constants for target inactivation. Recently, various catalysts were synthesized that use oxidative mechanisms to selectively cleave/inactivate therapeutic targets, including HIV RRE RNA or angiotensin converting enzyme (ACE). These oxidative mechanisms, which typically involve reactive oxygen species (ROS), provide access to comparatively high rate constants for target inactivation. Target-binding affinity, co-reactant selectivity, reduction potential, coordination unsaturation, ROS products (metal-associated vs metal-dissociated; hydroxyl vs superoxide), and multiple-turnover redox chemistry were studied for each catalyst, and these parameters were related to the efficiency, selectivity, and mechanism(s) of inactivation/cleavage of the corresponding target for each catalyst. Important factors for future oxidative catalyst development are 1) positioning of catalyst reduction potential and redox reactivity to match the physiological environment of use, 2) maintenance of catalyst stability by use of chelates with either high denticity or other means of stabilization, such as the square planar geometric stabilization of Ni- and Cu-ATCUN complexes, 3) optimal rate of inactivation of targets relative to the rate of generation of diffusible ROS, 4) targeting and linker domains that afford better control of catalyst orientation, and 5) general bio-availability and drug delivery requirements.


Subject(s)
Humans , Peptide Hydrolases/pharmacokinetics , Reactive Oxygen Species/pharmacology , Coordination Complexes/pharmacokinetics , Molecular Targeted Therapy/methods , Oxidation-Reduction , Peptide Hydrolases/chemical synthesis , Biological Availability , Catalysis , Genes, env , Peptidyl-Dipeptidase A/metabolism
7.
Bioorg Med Chem Lett ; 22(14): 4640-4, 2012 Jul 15.
Article in English | MEDLINE | ID: mdl-22726930

ABSTRACT

Recently, we reported substrate-based pentapeptidic BACE1 inhibitors possessing a hydroxymethylcarbonyl isostere as a substrate transition-state mimic. These inhibitors showed potent inhibitory activities in enzymatic and cell assays. We also designed and synthesized non-peptidic and small-sized inhibitors possessing a heterocyclic scaffold at the P(2) position. By studying the structure-activity relationship of these inhibitors, we found that the σ-π interaction of an inhibitor with the BACE1-Arg235 side chain played a key role in the inhibition mechanism. Hence, we optimized the inhibitors with a focus on their P(2) regions. In this Letter, a series of novel BACE1 inhibitors possessing a 5-nitroisophthalic scaffold at the P(2) position are described along with the results of the related structure-activity relationship study. These small-sized inhibitors are expected improved membrane permeability and bioavailability.


Subject(s)
Amyloid Precursor Protein Secretases/antagonists & inhibitors , Aspartic Acid Endopeptidases/antagonists & inhibitors , Nitro Compounds/chemistry , Peptide Hydrolases/chemical synthesis , Phthalic Acids/chemistry , Models, Molecular , Molecular Structure , Nitro Compounds/pharmacology , Peptide Hydrolases/pharmacology , Phthalic Acids/pharmacology , Structure-Activity Relationship
8.
Chem Asian J ; 5(6): 1389-94, 2010 Jun 01.
Article in English | MEDLINE | ID: mdl-20446336

ABSTRACT

The use of nanobiocatalysts, with the combination of nanotechnology and biotechnology, is considered as an exciting and rapidly emerging area. The use of iron oxide magnetic nanoparticles, as enzyme immobilization carriers, has drawn great attention because of their unique properties, such as controllable particle size, large surface area, modifiable surface, and easy recovery. In this study, various gamma-Fe(2)O(3)/Fe(3)O(4) magnetic nanoparticles with immobilized proteases were successfully prepared by three different immobilization strategies including A) direct binding, B) with thiophene as a linker, and C) with triazole as a linker. The oligopeptides syntheses catalyzed by these magnetic nanoparticles (MNPs) with immobilized proteases were systematically studied. Our results show that i) for magnetic nanoparticles immobilized alpha-chymotrypsin, both immobilization strategies A and B furnished good reusability for the Z-Tyr-Gly-Gly-OEt synthesis, the MNPs enzymes can be readily used at least five times without significant loss of its catalytic performance: ii) In the case of Z-Asp-Phe-OMe synthesis catalyzed by magnetic nanoparticles immobilized thermolysin, immobilization Strategy B provided the best recyclability: iii) For the immobilized papain, although Strategy A or B afforded an immobilized enzyme for the first cycle of Z-Ala-Leu-NHNHPh synthesis in good yield, their subsequent catalytic activity decreased rapidly. In general, the gamma-Fe(2)O(3) MNPs were better for use as an immobilization matrix, rather than the Fe(3)O(4) MNPs, owing to their smaller particle size and higher surface area.


Subject(s)
Enzymes, Immobilized/chemical synthesis , Oligopeptides/chemical synthesis , Peptide Hydrolases/chemical synthesis , Biocatalysis , Ferric Compounds , Ferrosoferric Oxide , Magnetics , Metal Nanoparticles , Peptide Hydrolases/chemistry , Solvents
9.
Chembiochem ; 9(18): 2920-8, 2008 Dec 15.
Article in English | MEDLINE | ID: mdl-19021141

ABSTRACT

Allostery is a basic principle of control of enzymatic activities based on the interaction of a protein or small molecule at a site distinct from an enzyme's active center. Allosteric modulators represent an alternative approach to the design and synthesis of small-molecule activators or inhibitors of proteases and are therefore of wide interest for medicinal chemistry. The structural bases of some proteinaceous and small-molecule allosteric protease regulators have already been elucidated, indicating a general mechanism that might be exploitable for future rational design of small-molecule effectors.


Subject(s)
Peptide Hydrolases/chemistry , Allosteric Regulation , Caspase Inhibitors , Caspases/chemistry , Caspases/metabolism , Chemistry, Pharmaceutical , Crystallography, X-Ray , Drug Design , Models, Molecular , Peptide Hydrolases/chemical synthesis , Peptide Hydrolases/metabolism , Protein Conformation , Protein Structure, Tertiary , Serine Endopeptidases/chemistry , Serine Endopeptidases/metabolism , Structure-Activity Relationship
10.
Acc Chem Res ; 36(7): 562-70, 2003 Jul.
Article in English | MEDLINE | ID: mdl-12859217

ABSTRACT

Effective artificial enzymes have been designed by adopting macromolecular systems for catalyst-substrate complexes. Artificial active sites comprising two or more organic functional groups were built on macromolecular backbones, leading to several types of organic artificial proteases. The activity of metal centers for peptide or DNA hydrolysis was greatly enhanced by attachment to polystyrene, leading to artificial metallopeptidases with substrate selectivity as well as artificial metallonucleases with high catalytic activity for double stranded DNA. A small artificial protease selective for a macromolecular target protein was synthesized. Target-specific artificial proteases can be used as protein-cleaving catalytic drugs.


Subject(s)
Peptide Hydrolases/chemical synthesis , Peptide Hydrolases/metabolism , Catalysis , Macromolecular Substances , Metalloproteases/chemical synthesis , Metalloproteases/chemistry , Metalloproteases/metabolism , Nucleic Acids/metabolism , Peptide Hydrolases/chemistry , Polymers/chemistry , Polymers/metabolism , Substrate Specificity
11.
Arch Biochem Biophys ; 277(2): 306-11, 1990 Mar.
Article in English | MEDLINE | ID: mdl-2178555

ABSTRACT

A 99-amino acid protein having the deduced sequence of the protease from human immunodeficiency virus type 2 (HIV-2) was synthesized by the solid phase method and tested for specificity. The folded peptide catalyzes specific processing of a recombinant 43-kDa GAG precursor protein (F-16) of HIV-1. Although the protease of HIV-2 shares only 48% amino acid identity with that of HIV-1, the HIV-2 enzyme exhibits the same specificity toward the HIV-1 GAG precursor. Fragments of 34, 32, 24, 10, and 9 kDa were generated from F-16 GAG incubated with the protease. N-terminal amino acid sequence analysis of proteolytic fragments indicate that cleavage sites recognized by HIV-2 protease are identical to those of HIV-1 protease. The verified cleavage sites in F-16 GAG appear to be processed independently, as indicated by the formation of the intermediate fragments P32 and P34 in nearly equal ratios. The site nearest the amino terminus is quite conserved between the two viral GAG proteins (...VSQNY-PIVQN...in HIV-1,...KGGNY-PVQHV...in HIV-2). In contrast, the putative second site (...IPFAA-AQQKG...) of HIV-2 GAG shares minimal sequence identity with site 2 of HIV-1 GAG (...SATIM-MQRGN...). These sequence variations in the substrates suggest higher order structural features that may influence recognition by the proteases. Pepstatin A inhibits HIV-2 protease, whereas 1,10-phenanthroline and phenylmethylsulfonylfluoride do not; these results are in agreement with the finding that proteases of HIV and other retroviruses are aspartyl proteases.


Subject(s)
Gene Products, gag/metabolism , HIV-1/enzymology , Peptide Hydrolases/metabolism , Amino Acid Sequence , HIV-1/metabolism , Molecular Sequence Data , Peptide Hydrolases/chemical synthesis , Protein Precursors/metabolism , Recombinant Proteins/metabolism , Sequence Homology, Nucleic Acid , Substrate Specificity
12.
Biochem Biophys Res Commun ; 156(1): 297-303, 1988 Oct 14.
Article in English | MEDLINE | ID: mdl-3052448

ABSTRACT

The mature proteins of retroviruses originate as a result of proteolytic cleavages of polyprotein precursors. Retroviruses encode proteases responsible for several of these processing events, making them potential antiviral drug targets. A 99-amino acid HIV-1 protease, produced by chemical synthesis or by expression in bacteria, is shown here to hydrolyze peptides corresponding to all of the known cleavage sites in the HIV-1 gag and pol polyproteins. It does not hydrolyze peptides corresponding to an env cleavage site or a distantly related retroviral gag cleavage site.


Subject(s)
HIV-1/enzymology , Peptide Hydrolases/metabolism , Retroviridae Proteins/metabolism , Amino Acid Sequence , Antigens, Viral , Gene Products, gag , HIV-1/genetics , Hydrolysis , Kinetics , Peptide Hydrolases/chemical synthesis , Peptide Hydrolases/genetics , Substrate Specificity
13.
Cell ; 54(3): 363-8, 1988 Jul 29.
Article in English | MEDLINE | ID: mdl-3293801

ABSTRACT

A protein corresponding to the putative protease of the human immunodeficiency virus 1 (HIV-1) has been prepared by total chemical synthesis. This 99 residue synthetic enzyme showed specific proteolytic activity on fragments of the natural gag precursor and on synthetic peptide substrates, two of which released fragments corresponding to the N terminus and C terminus of the protease molecule itself. The observed substrate specificity was not restricted to cleavage at Phe/Tyr-Pro bonds. Inhibition studies provided direct evidence that the HIV-1 protease belongs to the family of aspartic proteases. The availability of the HIV-1 protease as a defined molecular species has important implications for the design of specific inhibitors that do not interfere with the host cell metabolism as a possible route to antiviral agents against acquired immunodeficiency syndrome (AIDS).


Subject(s)
HIV/enzymology , Peptide Hydrolases/chemical synthesis , Amino Acid Sequence , Chromatography, High Pressure Liquid , Electrophoresis, Polyacrylamide Gel , Gene Products, gag , Molecular Sequence Data , Pepstatins/pharmacology , Peptide Hydrolases/genetics , Peptide Hydrolases/metabolism , Peptides/metabolism , Protease Inhibitors/pharmacology , Protein Precursors/genetics , Retroviridae Proteins/genetics , Substrate Specificity
14.
Acta Pathol Microbiol Scand A ; 87A(5): 387-92, 1979 Sep.
Article in English | MEDLINE | ID: mdl-43071

ABSTRACT

A florid necrotizing glomerulonephritis was found in all 48 pigs that were fed a waste product from the industrial production of the proteolytic enzyme Alcalase NOVO. In addition, three of the animals developed a lesion identical to polyarteritis nodosa. Focal necrosis of the glomeruli was observed in all animals. Electron microscopy showed electron dense deposits at the subendothelial and subepithelial side of the basement membrane of the glomerular capillary wall and in the mesangium. Immunofluorescence microscopy showed IgM in a fine granular pattern in the glomeruli of all 48 pigs. This appears to be the first report on nutritionally induced glomerulonephritis and polyarteritis nodosa in pigs.


Subject(s)
Animal Feed/adverse effects , Glomerulonephritis/etiology , Polyarteritis Nodosa/etiology , Animals , Fluorescent Antibody Technique , Glomerulonephritis/immunology , Glomerulonephritis/pathology , Immunoglobulin G/analysis , Immunoglobulin M/analysis , Kidney Glomerulus/immunology , Kidney Glomerulus/pathology , Kidney Glomerulus/ultrastructure , Necrosis , Peptide Hydrolases/chemical synthesis , Polyarteritis Nodosa/pathology , Swine
SELECTION OF CITATIONS
SEARCH DETAIL
...