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1.
Adv Exp Med Biol ; 1148: 81-103, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31482495

RESUMO

Enzymes are key biological macromolecules that support life by accelerating the conversion of target molecules to desired products in many biochemical reactions. Enzymes are characterized by high affinity, specificity and great catalytic efficiency. Owing to their unique characteristics, enzymes have attracted significant attention for use in therapeutic settings as a distinct class of drugs different from other types of medicines. Enzyme-based therapies are currently in use for the treatment of a wide range of diseases, including leukemia, metabolic disorders, inflammation and cardiovascular disease. However, several challenges, such as immunogenicity and stability, remain. X-ray crystallography has provided key structural insights into the understanding of the molecular basis of diseases and development of enzyme-based therapies. Here, the role of X-ray crystallography in the development of therapeutic enzymes is examined and several examples are provided.


Assuntos
Cristalografia por Raios X , Enzimas/química , Enzimas/farmacologia , Relação Estrutura-Atividade
2.
Adv Exp Med Biol ; 1148: 105-114, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31482496

RESUMO

Fluorescence spectroscopy is one of the most important techniques in the study of therapeutic enzymes. The fluorescence phenomenon has been discovered and exploited for centuries, while therapeutic enzymes have been used in treatment of disease for only decades. This chapter provides a brief summary of the current applications of fluorescence methods in studying therapeutic enzymes to provide some insights on the selection of proper method tailored to the goal. First a brief introduction about therapeutic enzymes and history of fluorescence were provided, followed by discussions on how fluorescence was applied in the studies. Four popular fluorescence methods are discussed: fluorescence tracing, fluorescence resonance energy transfer (FRET), fluorescence quenching and fluorescence polarization. Selected application of the fluorescence methods in studying therapeutic enzymes are listed, and discussed in details in the following paragraphs.


Assuntos
Enzimas/química , Transferência Ressonante de Energia de Fluorescência , Espectrometria de Fluorescência , Enzimas/farmacologia , Coloração e Rotulagem
3.
Adv Exp Med Biol ; 1148: 131-150, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31482498

RESUMO

Enzymes are biocatalysts that have found profound applications in the current biotherapeutic industry and play a crucial role in diagnosis, prevention, and biochemical analysis of major diseases. However, stability, protein degradation and immunogenicity in the body present unique challenges that are faced upon sustained use of such enzymes. The present chapter is an attempt to dissect the state-of-the-art in relation to the challenges of development of therapeutic enzymes and the recent advances to address them. At the very outset, diseases where enzymes have found effective applications and the various causes of enzyme instability have been discussed. In recent times, polymer or nano- conjugated resistant delivery methods, as well as mutagenesis have led to manifold increase in enzyme stability against thermal denaturation, acidic gut environment, proteolysis and immunogenicity. Further, methods of analytical characterization of proteins have been highlighted and explored to shape future research directions.


Assuntos
Estabilidade Enzimática , Enzimas/química , Enzimas/farmacologia , Proteólise
5.
Phys Rev Lett ; 123(3): 038101, 2019 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-31386470

RESUMO

Synthesis of biopolymers such as DNA, RNA, and proteins are biophysical processes aided by enzymes. The performance of these enzymes is usually characterized in terms of their average error rate and speed. However, because of thermal fluctuations in these single-molecule processes, both error and speed are inherently stochastic quantities. In this Letter, we study fluctuations of error and speed in biopolymer synthesis and show that they are in general correlated. This means that, under equal conditions, polymers that are synthesized faster due to a fluctuation tend to have either better or worse errors than the average. The error-correction mechanism implemented by the enzyme determines which of the two cases holds. For example, discrimination in the forward reaction rates tends to grant smaller errors to polymers with faster synthesis. The opposite occurs for discrimination in monomer rejection rates. Our results provide an experimentally feasible way to identify error-correction mechanisms by measuring the error-speed correlations.


Assuntos
Biopolímeros/biossíntese , Enzimas/química , Enzimas/metabolismo , Biopolímeros/química , DNA/biossíntese , DNA/química , Humanos , Modelos Biológicos , Modelos Químicos , RNA/biossíntese , RNA/química
6.
Phys Chem Chem Phys ; 21(35): 18811-18815, 2019 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-31468044

RESUMO

Recent experiments have reported that diffusion of enzymes can be enhanced in the presence of their substrates. Using a fluctuating dumbbell model of enzymes, it has been argued that such an enhancement can be rationalized by the reduction of the enzyme size and by the suppression of the hydrodynamically coupled conformational fluctuations, induced by binding a substrate or an inhibitor to the enzyme [Nano Lett. 2017, 17, 4415]. Herein, we critically examine these expectations via extensive Brownian dynamics simulations of a similar model. The numerical results show that neither of the two mechanisms can cause an enhancement comparable to that reported experimentally, unless very large, physically counter-intuitive, enzyme deformations are invoked.


Assuntos
Enzimas/química , Enzimas/metabolismo , Simulação de Dinâmica Molecular , Difusão , Modelos Químicos
7.
Phys Rev Lett ; 122(23): 238102, 2019 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-31298900

RESUMO

The enormous catalytic power of natural enzymes relies on the ability to overcome the bottleneck event in the enzymatic cycle, yet the underlying physical mechanisms are not fully understood. Here, by performing molecular simulations of the whole enzymatic cycle for a model multisubstrate enzyme with a dynamic energy landscape model, we show that multisubstrate enzymes can utilize steric frustration to facilitate the rate-limiting product-release step. During the enzymatic cycles, the bottleneck product is actively squeezed out by the binding of a new substrate at the neighboring site through the population of a substrate-product cobound complex, in which the binding pockets are frustrated due to steric incompatibility. Such steric frustration thereby enables an active mechanism of product release driven by substrate-binding energy, facilitating the enzymatic cycle.


Assuntos
Enzimas/química , Enzimas/metabolismo , Modelos Químicos , Adenilato Quinase/química , Adenilato Quinase/metabolismo , Modelos Moleculares , Conformação Proteica , Relação Estrutura-Atividade , Termodinâmica
8.
Food Chem ; 298: 124928, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31272053

RESUMO

Sonication can significantly enhance amino acids (AAs) release to accelerate maturation during short-term and low-salt soy sauce fermentation. Here, sonication was applied at 68 kHz (60 W/L/10 min/8 circles) to determine its effects on the taste during long-term and high-salt soy sauce fermentation. The possible mechanisms were explored by analyzing differences in enzymes profile, proximate indices, molecular weight distribution of peptides, AAs composition and microstructures of sonicated moromis and their controls. Sonication greatly elevated levels of organic taste compounds ranging from 8.4% to 22.2%, but lowered levels of NaCl (6.0%), peptides ≤ 1 kDa (5.2%), histidine (20.5%) and glutamic acid (3.4%). Compared to its controls, sonicated raw soy sauces also had a more harmonious and palatable taste. Increased enzymes' activities and formation of more surface area and reaction sites in sonicated moromis might be the possible mechanisms for sonication to elevate levels of taste compounds and sensory quality of soy sauce.


Assuntos
Alimentos Fermentados , Sonicação/métodos , Alimentos de Soja , Paladar , Aminoácidos/análise , Enzimas/química , Enzimas/metabolismo , Fermentação , Ácido Glutâmico/análise , Humanos , Peso Molecular , Peptídeos/análise , Peptídeos/química , Cloreto de Sódio na Dieta/análise
9.
J Sci Food Agric ; 99(13): 5702-5710, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31149736

RESUMO

BACKGROUND: Glycosylated compounds are one of the main fractions of the yeast cell wall. Thanks to their amphiphilic structure, they have been studied as stabilizers in food emulsions over a broad range of pH conditions with encouraging results. Nevertheless, extraction costs still represent an important limit for their application in the food industry. RESULTS: In this research, four extraction methods were applied to yeast cells exploiting both physical (heating and sonication) and enzymatic approaches (use of three industrial enzyme preparations, namely Glucanex®, Sur Lies and Elevage). A fifth method involving a pure ß-glucanase enzyme (Zymolyase) was taken as reference. These extraction methods were applied to the oenological strain Saccharomyces cerevisiae EC1118, and their extraction yields and chemical properties (quantitative and qualitative determination of sugars and proteins) were studied. Emulsifying activities were determined at three different pH values (3, 5 and 7). Extractions with Physical, Glucanex and Sur Lies methods were the most successful approaches to obtain relevant amounts of yeast compounds with good emulsifying activities for 2:1 oil-in-water emulsions at pH 3 and 7 over 48 h. CONCLUSIONS: These results indicate that there is the potential for the extraction approaches here proposed to become viable tools for the recovery of yeast compounds to be used as emulsifiers in foods. This approach can be considered as the starting point to explore the possibility to exploit yeast by-products from the fermentation processes (e.g. fermentation lees from wine and beer making) as valuable compounds for food applications. © 2019 Society of Chemical Industry.


Assuntos
Emulsões/química , Enzimas/química , Saccharomyces cerevisiae/química , Biocatálise , Parede Celular/química
10.
J Food Sci ; 84(7): 1986-1991, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31192461

RESUMO

Cassava leaves are a valuable source of protein but the cyanogenic potential limits their use as food and feed. Four different treatments were investigated to detoxify cassava leaves. Thermal (55 °C for 6 hr), sodium bicarbonate (0.4% NaHCO3 , 55 °C for 6 hr), enzymatic (0.32% Multifect® GC Extra, 4 hr), and ultrasonic treatments (500 W, 35 kHz, 55 °C, 0.25 hr) reduced the total cyanide (µg HCN equivalents per g fresh leaf or ppm) content by 90%, 93%, 82%, and 84% while the cyanide content reduction in the respective controls was 85%, 90%, 79%, and 84%, respectively. The sodium bicarbonate treatment was found to be the most effective treatment. Therefore, it was further optimized by varying time and temperature. A significant effect on the cyanide content was observed by changing the incubation time while no significant effect of temperature was noticed. Nevertheless, extended incubation time during sodium bicarbonate treatment reduced ascorbic acid content by 7% and 39% when leaves were incubated with sodium bicarbonate for 0.5 hr and 48 hr, respectively. PRACTICAL APPLICATION: Cyanogenic glucosides are the major toxic compound in cassava leaves, which limits their use as food and feed. The methods proposed in this study can be used to detoxify cassava leaves, which are generally considered as an inferior by-product. Hence, detoxified cassava leaves may contribute to fulfil world protein demand in an eco-sustainable way.


Assuntos
Cianetos/química , Manipulação de Alimentos/métodos , Glicosídeos/química , Manihot/química , Folhas de Planta/química , Biocatálise , Cianetos/toxicidade , Enzimas/química , Glicosídeos/toxicidade , Temperatura Alta , Manihot/toxicidade , Folhas de Planta/toxicidade , Bicarbonato de Sódio/química , Ultrassom
11.
Mar Pollut Bull ; 142: 129-134, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31232285

RESUMO

Standardized methods for the digestion of biota for microplastic analysis are currently lacking. Chemical methods can be effective, but can also cause damage to some polymers. Enzymatic methods are known to be gentler, but often laborious, expensive and time consuming. A novel tissue digestion method with pancreatic enzymes and a pH buffer (Tris) is here presented in a comparison to a commonly applied digestion protocol with potassium hydroxide. The novel protocol demonstrates a highly efficient removal of bivalve tissue (97.7 ±â€¯0.2% dry weight loss) already over-night. Furthermore, it induces no impairment in terms of ability to correctly identify four pre-weathered plastic polymers and six textile fiber polymers by Fourier transform infrared spectroscopy after exposure. The high-throughput protocol requires minimal handling, is of low cost and does not pose risk to the performer or the environment. It is therefore suggested as a candidate for a standardized digestion protocol, enabling successful analysis of microplastics ingested by bivalves.


Assuntos
Bivalves/química , Ecotoxicologia/métodos , Plásticos/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Animais , Tampões (Química) , Monitoramento Ambiental/métodos , Enzimas/química , Concentração de Íons de Hidrogênio , Hidróxidos/química , Plásticos/análise , Compostos de Potássio/química , Espectroscopia de Infravermelho com Transformada de Fourier , Têxteis/análise , Poluentes Químicos da Água/análise
12.
Food Chem ; 297: 124955, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253342

RESUMO

This study aimed to investigate the effect of hydrogen peroxide (H2O2) on membrane lipids metabolism and its relation to pulp breakdown development of longan fruit during postharvest storage. Compared to the control longans, H2O2-treated longans showed higher pulp breakdown index, cell membrane permeability, and activities of phospholipase D (PLD), lipase and lipoxygenase (LOX). Moreover, H2O2-treated longans maintained higher levels of pulp phosphatidic acid (PA) and saturated fatty acids (SFA). However, H2O2-treated longans exhibited lower levels of pulp phosphatidylcholine (PC), phosphatidylinositol (PI) and unsaturated fatty acids (USFA), lower index of unsaturated fatty acids (IUFA), and lower ratio of USFA to SFA (U/S). These findings demonstrated that H2O2 caused the increased activities of enzymes involving in membrane lipids degradation and the accelerated decompositions of membrane USFA and phospholipids in longan pulp, which eventually triggered the destruction of the pulp cell membrane structure and the development of pulp breakdown in longans during storage.


Assuntos
Enzimas/metabolismo , Frutas/química , Peróxido de Hidrogênio/farmacologia , Lipídeos de Membrana/metabolismo , Sapindaceae/química , Enzimas/química , Ácidos Graxos/análise , Ácidos Graxos/química , Armazenamento de Alimentos , Frutas/efeitos dos fármacos , Frutas/metabolismo , Peróxido de Hidrogênio/química , Lipase/química , Lipase/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Lipoxigenase/química , Lipoxigenase/metabolismo , Lipídeos de Membrana/química , Fosfolipase D/metabolismo , Fosfolipídeos/química , Fosfolipídeos/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Sapindaceae/efeitos dos fármacos , Sapindaceae/metabolismo
13.
Chemosphere ; 233: 207-215, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31173958

RESUMO

Rain garden is a typical facility with many applications in urban low impact development (LID). It plays an important role in regulating runoff water quantity and quality. Two rain gardens with the discharge ratios of 20:1 and 15:1 were used as studied facilities. Seven soil sampling events were conducted from April 2017 to February 2019 to study the influences of stormwater concentration infiltration in rain gardens on soil nitrogen (N), phosphorus (P) and TOC and their relations with enzymes. The results showed that the contents of soil TN and NO2-N + TON in gardens gradually decreased with time, while those of NH3-N and TP increased with time. The content of NO3-N varied greatly with time, and there was no obvious rule. TOC increased first and then decreased. Vertical distributions of N, P and TOC showed that the contents of NH3-N, NO2-N + TON and TN at 0-50 cm were high, so the upper soil was the sensitive area to the influence of stormwater concentration infiltration in rain gardens. The content of NH3-N decreased gradually with the increase of soil depth, but those of NO3-N and TP increased with the soil depth. Therefore, NO3-N and TP migrated down with water infiltration in soil, and preventing NO3-N and P leaching was critical for effective N and P removal though rain gardens. Soil urease (SU), sucrose (SS), protease (SP) and acid phosphatase (SAP) had a good linear relationship with N, P and TOC, and R2were all greater than 0.5.


Assuntos
Carbono/química , Enzimas/metabolismo , Nitrogênio/análise , Fósforo/análise , Solo/química , Carbono/análise , China , Monitoramento Ambiental , Enzimas/química , Jardins , Nitrogênio/química , Fósforo/química , Chuva
14.
Biophys Chem ; 252: 106209, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31254793

RESUMO

Thermodynamics and kinetics of biochemical reactions depend not only on temperature, but also on pressure and on the presence of cosolvents in the reaction medium. Understanding their effects on biochemical processes is a crucial step towards the design and optimization of industrially relevant enzymatic reactions. Such reactions typically do not take place in pure water. Cosolvents might be present as they are either required as stabilizer, as solubilizer, or in their function to overcome thermodynamic or kinetic limitations. Further, a vast number of enzymes has been found to be piezophilic or at least pressure-tolerant, meaning that nature has adapted them to high-pressure conditions. In this manuscript, we review existing data and we additionally present some new data on the combined cosolvent and pressure influence on the kinetics of biochemical reactions. In particular, we focus on cosolvent and pressure effects on Michaelis constants and catalytic constants of α-CT-catalysed peptide hydrolysis reactions. Two different substrates were considered in this work, N-succinyl-L-phenylalanine-p-nitroanilide and H-phenylalanine-p-nitroanilide. Urea, trimethyl-N-amine oxide, and dimethyl sulfoxide have been under investigation as these cosolvents are often applied in technical as well as in demonstrator systems. Pressure effects have been studied from ambient pressure up to 2 kbar. The existing literature data and the new data show that pressure and cosolvents must not be treated as independent effects. Non-additive interactions on a molecular level lead to a partially compensatory effect of cosolvents and pressure on the kinetic parameters of the hydrolysis reactions considered.


Assuntos
Biocatálise , Enzimas/metabolismo , Hidrólise , Pressão , Solventes/química , Enzimas/química , Cinética , Simulação de Dinâmica Molecular , Termodinâmica
15.
Anal Chim Acta ; 1067: 31-47, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31047147

RESUMO

Novel enzymatic microsystems have strong prospects in chemical and biological analysis due to their low consumption of reagents, fast analysis time, easy manipulation and satisfactory portability. Nanomaterials (NMs) provide a favorable platform for integrating enzymes into microsystems with enhanced selectivity and sensitivity. Various NM-enzyme immobilization strategies applied in the fabrication of capillary-based and chip-based enzymatic microsystems are summarized in this manuscript. We focus on highlighting the advantages of employing NM-based enzymatic microsystems for enantioseparation, inhibitor screening, bioreaction and biosensing. Innovative nanocomposites and NM-functionalized monoliths used to construct multienzymatic microsystems are also illustrated. The general development trend identified in this review indicates that the application of NMs has significantly improved enzymatic microsystem performance.


Assuntos
Disciplinas das Ciências Biológicas/métodos , Técnicas Biossensoriais , Química/métodos , Enzimas/química , Nanocompostos/química , Enzimas/metabolismo , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo
16.
Nat Commun ; 10(1): 2169, 2019 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-31092815

RESUMO

Previous studies have shown that aqueous solutions of designer surfactants enable a wide variety of valuable transformations in synthetic organic chemistry. Since reactions take place within the inner hydrophobic cores of these tailor-made nanoreactors, and products made therein are in dynamic exchange between micelles through the water, opportunities exist to use enzymes to effect secondary processes. Herein we report that ketone-containing products, formed via initial transition metal-catalyzed reactions based on Pd, Cu, Rh, Fe and Au, can be followed in the same pot by enzymatic reductions mediated by alcohol dehydrogenases. Most noteworthy is the finding that nanomicelles present in the water appear to function not only as a medium for both chemo- and bio-catalysis, but as a reservoir for substrates, products, and catalysts, decreasing noncompetitive enzyme inhibition.


Assuntos
Química Orgânica/métodos , Enzimas/química , Metais/química , Elementos de Transição/química , Catálise , Micelas , Estrutura Molecular , Tensoativos/química , Água/química
17.
Chemosphere ; 229: 471-480, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31091488

RESUMO

The functional stability of soil enzymes is fundamental to the sustainability of soil biochemical processes and is affected by many environmental stressors. This study focused on the influences of long-term arsenic (As) contamination on soil enzyme functional stability: the resistance (ratio of the disturbed to control) and resilience (integrated recovery rate) of soil enzyme activities (ß-glucosidase, urease, acid phosphatase, fluorescein diacetate (FDA) hydrolase) over 30 days incubation after an experimental heat disturbance (50 oC for 18 h). Results showed that the resistance of soil enzymes to heat disturbance differed among the enzyme types and followed the order: urease > ß-glucosidase > acid phosphatase > FDA hydrolase. Urease activity was generally not affected and showed high stability against heat disturbance. The ß-glucosidase activity recovered to the control level by 30 days, while 80% and 90% recovery on average occurred for acid phosphatase and FDA hydrolase, respectively. Long-term As contamination altered soil enzyme functional resistance and resilience to heat disturbance and resulted in three kinds of responses: (i) no apparent alteration (urease); (ii) moderate As contamination increased enzyme heat resistance (ß-glucosidase); (iii) the resistance and resilience decreased with increasing As concentration (acid phosphatase and FDA hydrolase). The results demonstrated that different enzyme-catalytic biochemical processes have different functional stabilities under combined As and heat disturbance, and the negative changes in the soil enzyme activity led to losses in soil functions. Our study provides further evidence on the impacts of heavy metal/metalloid on soil enzyme functional stability in response to additional disturbance.


Assuntos
Arsênico/toxicidade , Enzimas/química , Poluentes do Solo/toxicidade , Solo/química , Arsênico/análise , China , Estabilidade Enzimática , Enzimas/metabolismo , Temperatura Alta , Microbiologia do Solo , Poluentes do Solo/análise
18.
Phys Rev E ; 99(3-1): 032421, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30999440

RESUMO

Inspired by recent experiments on chromosomal dynamics, we introduce an exactly solvable model for the interaction between a flexible polymer and a set of motorlike enzymes. The enzymes can bind and unbind to specific sites of the polymer and produce a dipolar force on two neighboring monomers when bound. We study the resulting nonequilibrium dynamics of the polymer and find that the motion of the monomers has several properties that were observed experimentally for chromosomal loci: a subdiffusive mean-square displacement and the appearance of regions of correlated motion. We also determine the velocity autocorrelation of the monomers and find that the underlying stochastic process is not fractional Brownian motion. Finally, we show that the active forces swell the polymer by an amount that becomes constant for large polymers.


Assuntos
Cromossomos/metabolismo , Enzimas/metabolismo , Modelos Moleculares , Algoritmos , Fenômenos Biomecânicos , Cromossomos/química , Enzimas/química , Modelos Químicos , Modelos Genéticos , Movimento (Física) , Polímeros/química , Processos Estocásticos
19.
Appl Microbiol Biotechnol ; 103(11): 4253-4268, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30957199

RESUMO

Enzymatic hydrolysis of polyethylene terephthalate (PET) has been the subject of extensive previous research that can be grouped into two categories, viz. enzymatic surface modification of polyester fibers and management of PET waste by enzymatic hydrolysis. Different enzymes with rather specific properties are required for these two processes. Enzymatic surface modification is possible with several hydrolases, such as lipases, carboxylesterases, cutinases, and proteases. These enzymes should be designated as PET surface-modifying enzymes and should not degrade the building blocks of PET but should hydrolyze the surface polymer chain so that the intensity of PET is not weakened. Conversely, management of PET waste requires substantial degradation of the building blocks of PET; therefore, only a limited number of cutinases have been recognized as PET hydrolases since the first PET hydrolase was discovered by Müller et al. (Macromol Rapid Commun 26:1400-1405, 2005). Here, we introduce current knowledge on enzymatic degradation of PET with a focus on the key class of enzymes, PET hydrolases, pertaining to the definition of enzymatic requirements for PET hydrolysis, structural analyses of PET hydrolases, and the reaction mechanisms. This review gives a deep insight into the structural basis and dynamics of PET hydrolases based on the recent progress in X-ray crystallography. Based on the knowledge accumulated to date, we discuss the potential for PET hydrolysis applications, such as in designing waste stream management.


Assuntos
Enzimas/metabolismo , Polietilenotereftalatos/metabolismo , Poluentes Químicos da Água/metabolismo , Biotransformação , Enzimas/química , Hidrólise , Modelos Moleculares , Conformação Proteica , Rios/química
20.
Acta Crystallogr F Struct Biol Commun ; 75(Pt 4): 299-306, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30950831

RESUMO

Adenylation enzymes play an important role in the selective incorporation of the cognate carboxylate substrates in natural product biosynthesis. Here, the biochemical and structural characterization of the adenylation enzyme IdnL7, which is involved in the biosynthesis of the macrolactam polyketide antibiotic incednine, is reported. Biochemical analysis showed that IdnL7 selects and activates several small amino acids. The structure of IdnL7 in complex with an L-alanyl-adenylate intermediate mimic, 5'-O-[N-(L-alanyl)sulfamoyl]adenosine, was determined at 2.1 Šresolution. The structure of IdnL7 explains the broad substrate specificity of IdnL7 towards small L-amino acids.


Assuntos
Adenina/metabolismo , Dissacarídeos/biossíntese , Enzimas/química , Enzimas/metabolismo , Streptomyces/enzimologia , Sequência de Aminoácidos , Sítios de Ligação , Cristalização , Lactamas , Ligantes , Homologia Estrutural de Proteína , Especificidade por Substrato
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