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1.
Food Chem Toxicol ; 186: 114571, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38452966

RESUMEN

This study investigated the preventive effect of heat-killed Lactobacillus plantarum (L. plantarum) on cholestasis-induced male reproductive toxicity in rats. Rats were divided into control normal, sham control, bile duct ligation (BDL) control, and BDL with heat-killed L. plantarum supplementation groups. The effects on sexual hormones, testicular and epididymal histology, sperm parameters, oxidative stress markers, and inflammatory gene expression were evaluated. Compared to the BDL control group, the BDL + heat-killed L. plantarum group showed higher levels of normal sperm, luteinizing hormone, testosterone, total antioxidant capacity, and catalase activity, indicating improved reproductive function. Conversely, markers of oxidative stress, such as total oxidative status, oxidative stress index, and carbonyl protein, were lower in the BDL + heat-killed L. plantarum group. The expression levels of inflammatory genes tumor necrosis factor-alpha and interleukin-6 were reduced, while interleukin-10 gene expression was increased in the BDL + heat-killed L. plantarum group. Histological evaluation confirmed the positive effects of heat-killed L. plantarum intervention on testicular parameters. In conclusion, heat-killed L. plantarum supplementation protects against cholestasis-induced male reproductive dysfunction in rats, as evidenced by improvements in hormonal balance, sperm quality, oxidative stress, and inflammation.


Asunto(s)
Colestasis , Lactobacillus plantarum , Ratas , Masculino , Animales , Lactobacillus plantarum/metabolismo , Calor , Semen/metabolismo , Colestasis/metabolismo , Antioxidantes/farmacología , Antioxidantes/metabolismo , Estrés Oxidativo , Hígado , Ligadura
2.
Biomed Res Int ; 2023: 5444301, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37082190

RESUMEN

Introduction: Bile duct ligation (BDL) and subsequent cholestasis are associated with oxidative stress and liver injury and fibrosis. Hesperidin (3,5,7-trihydroxyflavanone 7-rhamnoglucoside) is a flavanone glycoside abundant in citrus fruits. It has positive effects on diabetic retinopathy, reduced platelet aggregation, and blood flow alterations and has the potential to reduce liver injury in oxidative stress. The aim of this study was to evaluate the hepatoprotective effects of hesperidin on BDL-induced liver injury in rats. Methods: A total of 48 adult male Wistar rats were equally allocated to six eight-rat groups, namely, a healthy group, a sham group, a BDL+Vehicle group (BDL plus treatment with distilled water), a BDL+VitC group (BDL plus treatment with vitamin C 4.25 µg/kg), a BDL+Hesp100 group (BDL plus treatment with hesperidin 100 mg/kg/day), and a BDL+Hesp200 group (BDL plus treatment with hesperidin 200 mg/kg/day). Treatments were orally provided for 21 consecutive days. Finally, rats were sacrificed through heart blood sampling. Blood samples were centrifuged, and liver function, oxidative stress, and antioxidant parameters were assessed. Liver tissue was also assessed for oxidative stress, antioxidant, and histological parameters. The expression of inflammatory genes, namely, TGFß1, iNOS, Caspase-3, and α-SMA, was measured through polymerase chain reaction. Findings. Hesperidin supplementation was associated with significant decrease in the levels of liver enzymes, bilirubin, nitric oxide, malondialdehyde, protein carbonyl, and inflammatory gene expression; significant increase in the levels of total antioxidant capacity, glutathione, and superoxide dismutase and catalase enzyme activity; and significant improvement in the histological morphology and structure of the liver parenchyma. Conclusion: Hesperidin has significant positive effects on liver morphology and structure, inflammation, fibrosis, and oxidative stress in rats with BDL-induced cholestatic liver injury.


Asunto(s)
Colestasis , Hesperidina , Ratas , Masculino , Animales , Antioxidantes/farmacología , Antioxidantes/metabolismo , Hesperidina/farmacología , Ratas Wistar , Hígado/patología , Cirrosis Hepática/patología , Conductos Biliares/cirugía , Conductos Biliares/patología , Colestasis/complicaciones , Colestasis/tratamiento farmacológico , Colestasis/metabolismo , Estrés Oxidativo , Fibrosis , Ligadura
3.
Brain Behav ; 13(2): e2877, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36630182

RESUMEN

INTRODUCTION: Despite half a century of research on vitamin D (Vit. D), its link to substance abuse and dependence has only been discussed in recent decades. Evidence also shows the involvement of Vit. D in the evolution of dopaminergic neurons in the nucleus accumbens, an increase in the expression of tyrosine hydroxylase, and the regulation of dopaminergic processes. The novel idea for this work is taken from a hypothesis given about the effectiveness of Vit. D on dopamine signaling pathway. It is therefore presumed that Vit. D can be considered an effective therapeutic approach for narcotic addiction and substance abuse. METHODS: The animals were assigned into six groups (control, vehicle, Morphine [Mor.], and Vit. D [250, 500, and 1000 IU/kg, i.p.]). Following each conditioning session in a conditioned place preference (CPP) model, the animals received Vit. D. Afterward, the locomotor activity of the animals was assessed using open-field apparatus. Malondialdehyde (MDA), nitric oxide (NO), catalase (CAT), superoxide dismutase (SOD), thiol, and total antioxidant capacity (TAC) were measured in the brain. The relative DRD2 and GDNF expressions (%) were also measured in the hippocampus. RESULTS: Vit. D administration after Mor. caused a significant increase in the place preference index in the acquisition phase (p < .05). Vit. D altered the oxidation/antioxidation profiles (CAT, SOD, MDA, NO, TAC, and Thiol). Vit. D was more effective than Mor. in the expression of GDNF (p < .0001); however, in the expression of DRD2, this was only the case for 1000 IU Vit. D (p < .0001). CONCLUSIONS: Considering the increased place preference index induced by Mor., it can be concluded that Vit. D interacts via the oxidative pathway and DRD2-GDNF signaling to potentiate the Mor. effect.


Asunto(s)
Morfina , Trastornos Relacionados con Sustancias , Ratas , Animales , Morfina/farmacología , Vitamina D/farmacología , Factor Neurotrófico Derivado de la Línea Celular Glial , Vitaminas , Antioxidantes , Dopamina , Superóxido Dismutasa/metabolismo , Receptores de Dopamina D2
4.
Artículo en Inglés | MEDLINE | ID: mdl-36522610

RESUMEN

This study is aimed at evaluating the effects of heat-killed Lactobacillus plantarum (L. plantarum) on cholestatic liver injury induced by bile duct ligation (BDL) in rats. Rats in the first group were healthy (normal control) and in the second group underwent abdominal incision (sham control). Rats in the third and fourth groups underwent common bile duct ligation and were treated with either oral distilled water (BDL control group) or heat-killed L. plantarum (BDL + L. plantarum) for 28 days. Finally, rats were sacrificed, blood samples were analyzed through biochemical methods, liver and ileum tissue tissues were histologically assessed, and the expression of the αSMA, TNF-α, IL-6, and IL-10 genes in the liver and ZO-1 gene in ileum tissues were assessed through real-time PCR. The levels of bilirubin, liver function enzymes, NO, MDA, and carbonyl protein in the BDL + L. plantarum group were significantly lower than in the BDL control group (P ≤ 0.05). SOD and CAT activity in BDL + L. plantarum group was significantly greater than the BDL control group 1.4 and 3.0 times, respectively (P ≤ 0.001). Moreover, in the BDL + L. plantarum group, the expression of the α-SMA, TNF-α, and IL-6 genes was significantly lower (3.1, 2.9, and 2.5 times), and IL-10 and ZO-1 genes were significantly greater than the BDL control group by 2.1 and 3.6 times, respectively (P ≤ 0.05). The histological assessment also confirmed the greater effectiveness of heat-killed L. plantarum in improving the morphology and parenchymal structure of the liver. Taken together, our results suggest that heat-killed L. plantarum strains are potential therapeutic agents for hepatic fibrosis.

5.
Curr Pharm Des ; 28(40): 3313-3323, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36305136

RESUMEN

BACKGROUND: Cholestatic liver damage is a chronic disease caused by dysfunction of the hepaticbiliary system. Oxidative stress and inflammation are essential factors in the pathogenesis of cholestasis. Thus, the current study was designed to examine the effect of empagliflozin on bile duct ligation-induced liver damage in rats. METHODS: This study was done on male Wistar rats, which were randomly assigned to the four experimental groups: sham control (SC), bile duct ligation (BDL), SC plus empagliflozin (SC+EMPA) (receiving 10 mg of EMPA orally for 7 days), BDL plus empagliflozin 10 mg/kg (BDL+ EMPA). At the end of the study, the rats were sacrificed, and serum and tissue samples were collected to analyze biochemical parameters, biomarkers of oxidative stress, inflammatory markers, and histopathological changes. The molecular docking technique was performed to elucidate the interaction of EMPA and Cu/Zn-superoxide dismutase (SOD1). RESULTS: The results showed that BDL elevated the serum activity of ALT, AST, ALP, and levels of TBIL and TPro. BDL also intensifies the oxidative stress state in rats, which was confirmed by augmenting lipid peroxidation (MDA), protein oxidation (PCO), and altering antioxidant defense parameters through decreased SOD, catalase (CAT), and glutathione peroxidase (GPX) levels. Furthermore, the histopathological changes in the liver demonstrated the aggravation of inflammation and oxidative stress. In contrast, treatment with EMPA has shown anti-inflammatory and anti-oxidant effects by reducing TNF-α and IL-6 pro-inflammatory marker proteins, restoring the antioxidant status (increased SOD and GPX), reducing ALT, AST, ALP, TBIL levels, and protein oxidation, and improving the histopathological alterations through reducing bile duct proliferation, fibrosis, focal and portal inflammation. According to the attained findings, the SOD1 activity can be regulated by the EMPA. Our documentation presents direct evidence at the molecular level related to the ability of EMPA to exert its antioxidant performance through certain measures in a particular molecular route. CONCLUSION: The results showed EMPA to have hepatic protective effects in rats against cholestatic liver injury, an effect mediated by its antioxidant and anti-inflammatory properties.


Asunto(s)
Enfermedad Hepática Crónica Inducida por Sustancias y Drogas , Colestasis , Ratas , Masculino , Animales , Antioxidantes/farmacología , Simulación del Acoplamiento Molecular , Superóxido Dismutasa-1/metabolismo , Superóxido Dismutasa-1/farmacología , Enfermedad Hepática Crónica Inducida por Sustancias y Drogas/metabolismo , Enfermedad Hepática Crónica Inducida por Sustancias y Drogas/patología , Ratas Wistar , Hígado/metabolismo , Colestasis/tratamiento farmacológico , Colestasis/metabolismo , Colestasis/patología , Glutatión Peroxidasa/metabolismo , Conductos Biliares/metabolismo , Estrés Oxidativo , Superóxido Dismutasa/metabolismo , Superóxido Dismutasa/farmacología , Inflamación/metabolismo
6.
Biomed Res Int ; 2022: 4547312, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36132073

RESUMEN

Introduction: Diabetic nephropathy is one of the leading causes of end-stage renal disease worldwide. Uncontrolled hyperglycemia and subsequent production of glycation end-products activate the paths which lead to diabetic nephropathy. The aim of this study was to assess the effects of L-lysine on antioxidant capacity, biochemical factors, kidney function, HSP70 level, and the expression of the TGFß, VEGF, and RAGE genes in rats with streptozocin-induced diabetes mellitus. Methods: Thirty-two male Wistar rats were randomly allocated to four eight-rat groups, namely, a healthy group, a diabetic group treated with vehicle (DM + vehicle), a diabetic group treated with L-lysine (DM + Lys), and a healthy group treated with L-lysine (healthy + Lys). Rats in the DM + Lys and the healthy + Lys groups were treated with L-lysine 0.15%. The levels of fasting blood glucose, insulin, HbA1C, advanced glycation end-products (AGEs), lipid profile, serum creatinine, blood urea nitrogen, glomerular filtration rate, urine microalbumin, oxidative stress parameters, kidney histology and morphology, and TGFß, VEGF, and RAGE gene expressions were assessed. Findings. An eight-week treatment with L-lysine significantly reduced the levels of fasting blood glucose, AGEs, kidney function parameters, oxidative stress parameters, lipid profile, and the TGFß, VEGF, and RAGE gene expression and significantly increased the levels of serum insulin and tissue HSP70. Conclusion: Treatment with L-lysine seems to slow down the progression of diabetic nephropathy.


Asunto(s)
Diabetes Mellitus Experimental , Nefropatías Diabéticas , Animales , Antioxidantes/metabolismo , Antioxidantes/farmacología , Glucemia/metabolismo , Creatinina/metabolismo , Nefropatías Diabéticas/tratamiento farmacológico , Nefropatías Diabéticas/metabolismo , Productos Finales de Glicación Avanzada/metabolismo , Insulina/metabolismo , Riñón/patología , Lípidos , Lisina/metabolismo , Lisina/farmacología , Masculino , Estrés Oxidativo , Ratas , Ratas Wistar , Estreptozocina/farmacología , Factor de Crecimiento Transformador beta/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo
7.
Rep Biochem Mol Biol ; 11(1): 1-9, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35765518

RESUMEN

Background: Cannabinoids (CBs) have been found to regulate the immune system, affect innate and adaptive immune responses, and reduce inflammatory reactions. This study assessed the therapeutic effects of GW-405833 synthetic CB2 agonist on inflammatory factors as well as locomotor activity in experimental autoimmune encephalomyelitis (EAE). Methods: In this experimental study, 48 adult male C57BL/6 mice were randomly and equally assigned to eight groups. By injecting 250 mg of MOG35-55 peptide, EAE was induced. Every other day for 17 days after EAE onset, EAE-afflicted mice in groups 1-3 received an intraperitoneal injection of GW-405833 at a dose of 3, 10, and 30 mg/kg, respectively. Clinical status and locomotor activity, measured using the beam walking assay, were assessed every other day during the first 17 days after EAE onset. Mice were euthanized in day 17th of treatment and the serum levels of the IL-1ß, IL-12, CRP, and TNF-α proinflammatory cytokines as well as IL-4 and TGF-ß anti-inflammatory cytokines were measured by ELISA method. Results: Clinical manifestations of EAE in groups 2 and 3 were significantly milder than group 4 and locomotor activity in groups 1-3 was significantly better than group 4 in days 5-17 (p< 0.05). GW-405833 also significantly decreased the levels of IL-12, TNF-α, and CRP and significantly increased the levels of IL-4 and TGF-ß but had no significant effects on the level of IL-1ß. GW-405833 was not associated with significant side effects. Conclusion: The CB2 receptor agonist GW-405833, improves clinical conditions and reduces inflammation in mice with EAE.

8.
Biomed Res Int ; 2022: 6989963, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35155679

RESUMEN

This study is aimed at evaluating the effects of Securigera securidaca (SS) seed extract on cholestatic liver injury induced by bile duct ligation (BDL) in rats. Total polyphenols and flavonoids in SS seed extract were determined using a colorimetric assay, and their components were quantified using HPLC. Rats in four groups underwent BDL at the common bile duct and were treated for 21 days with either oral distilled water as vehicle, vitamin C, 100 mg/kg SS seed extract, or 200 mg/kg SS seed extract. Rats in the fifth group underwent abdominal incision without BDL and were treated with distilled water, and rats in the sixth group were healthy and received nothing. Finally, rats were sacrificed, blood samples were analyzed through biochemical methods, liver tissues were histologically assessed, and the expression of the TGFß-1, iNOS, caspase-3, and α-SMA genes in the liver was assessed through real-time PCR. BDL significantly increased, and SS seed extract significantly decreased the serum levels of bilirubin and liver function enzymes. Moreover, SS seed extract suppressed the expression of the TGFß-1, iNOS, caspase-3, and α-SMA genes, reduced the levels of nitric oxide, malondialdehyde, and protein carbonyl, and increased the levels of glutathione, total antioxidant capacity, and SOD and catalase enzyme activity in the serum and liver. Extract at a dose of 100 mg/kg had significant positive effects on liver morphology and parenchyma structure in a dose-dependent manner.


Asunto(s)
Colestasis/tratamiento farmacológico , Extractos Vegetales/farmacología , Securidaca , Animales , Biomarcadores/metabolismo , Cromatografía Líquida de Alta Presión , Modelos Animales de Enfermedad , Ligadura , Masculino , Extractos Vegetales/química , Ratas , Ratas Wistar , Semillas/química
9.
Pharmacol Rep ; 71(4): 682-687, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31201967

RESUMEN

BACKGROUND: Myocardial injury (MI) is an important heart condition and a major cause of morbidity and mortality worldwide. The current study was designed to investigate the cardioprotective effects of cerebrolysin (CLY) on the lesion severity and inflammatory factors in male rats using isoproterenol (ISO)-induced MI model. METHODS: MI in rats was induced by injecting ISO (100 mg/kg) subcutaneously (sc) on the first 2 days. Then, CLY (5 ml/kg) was injected intraperitoneally (ip) post-treatment for 7 days. On the 3rd day, creatine phosphokinase (CK-MB) and cardiac troponin I (cTnI) levels in serum and, on the 10th day, the TNF-α and IL6 levels in serum and heart tissue were measured by enzyme-linked immunosorbent assay (ELISA). Finally, the heart of each rat was dissected out and stained for histopathological examination. RESULTS: On the 3rd day, the serum CK-MB and cTnI levels in the ISO and CLY + ISO groups were significantly increased compared with that in the control and CLY + Sal groups. One week after the induction of MI, ISO administration showed a significant increase in the serum level of TNF-α in the ISO group compared with that in the control and CLY + Sal groups. Also, our findings showed only a moderate reduction in inflammatory cell infiltration and extent of edema following CLY treatment in the CLY + ISO group. Also, CLY induced vascular proliferation in the heart tissue. CONCLUSIONS: We conclude that the severity of pathological changes induced by ISO in MI (e.g. inflammation and edema) can be limited by CLY treatment.


Asunto(s)
Aminoácidos/farmacología , Cardiotónicos/farmacología , Infarto del Miocardio/tratamiento farmacológico , Miocardio/patología , Animales , Biomarcadores/sangre , Supervivencia Celular/efectos de los fármacos , Circulación Coronaria/efectos de los fármacos , Interleucina-6/metabolismo , Isoproterenol , Masculino , Células Musculares/efectos de los fármacos , Células Musculares/patología , Infarto del Miocardio/sangre , Infarto del Miocardio/inmunología , Miocardio/metabolismo , Ratas Wistar , Índice de Severidad de la Enfermedad , Factor de Necrosis Tumoral alfa/sangre
10.
Life Sci ; 227: 187-192, 2019 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-31028802

RESUMEN

AIMS: Myocardial injury (MI) is the principal cause of death from cardiovascular disease (CVD). The present study was conducted to investigate the ameliorative and antioxidant effects of cerebrolysin (CBL) on isoproterenol-induced MI in rats. METHODS: MI was induced in the rats by subcutaneously injecting 100 mg/kg of isoproterenol (ISO) in the first two days. The serum levels of creatine phosphokinase (CK-MB) and cardiac troponin I (cTnI) were measured on the third day to confirm MI. The post-treatment involved intraperitoneally injecting 5 ml/kg of CBL for 7 days. Nitric oxide (NO), malondialdehyde (MDA) in the heart tissue and catalase (CAT) and serum levels of superoxide dismutase (SOD) and glutathione peroxidase (GPX) were measured on the 10th day using the enzyme-linked immunosorbent assay (ELISA). Histopathological examinations of the heart tissue were also performed. FINDINGS: The present results suggested significant increases in CK-MB, cTnI, MDA and NO. A significant decrease was also observed in the ISO-treated rats in certain antioxidant enzymes, including CAT and GPX. CBL administration showed a significant ameliorative increase against the oxidative ISO-induced damage. Moreover, the histopathological findings showed lower levels of the infiltration of inflammatory cells and edema and vascular proliferation in the CBL-treated rats. SIGNIFICANCE: The present histopathological and biochemical findings attributed antioxidant properties to CBL in the rat myocardium and suggested protective effects on ISO-induced MI.


Asunto(s)
Aminoácidos/farmacología , Corazón/efectos de los fármacos , Infarto del Miocardio/tratamiento farmacológico , Aminoácidos/metabolismo , Animales , Antioxidantes/farmacología , Catalasa/metabolismo , Glutatión Peroxidasa/metabolismo , Isoproterenol/farmacología , Peroxidación de Lípido/efectos de los fármacos , Masculino , Malondialdehído/metabolismo , Infarto del Miocardio/patología , Miocardio/metabolismo , Óxido Nítrico/metabolismo , Estrés Oxidativo/efectos de los fármacos , Ratas , Ratas Wistar , Superóxido Dismutasa/metabolismo
11.
Protein J ; 38(2): 151-159, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30859376

RESUMEN

Immune response stimulation and inactivation of chondroitinase ABC I in physiological condition have been limited its use in various clinical conditions as a bacterial enzyme drug. In the present study, we have investigated some structural and functional features of N∆89, C∆274 and N∆89C∆274; three designed truncated cABC I, in order to clarify the unclear role of two terminal parts of cABC I i.e., the 1-89 and 747-1021 amino acids sequences of the full length enzyme through truncation. As a result, the numbers of potential epitopes, the susceptibility to trypsin digestion, ANS fluorescence spectra, and fluorescence quenching using KI and acrylamide were diminished for N∆89 and C∆274 in comparison to the wild type. Secondary and tertiary structure investigation for N∆89 and C∆274 revealed that the intrinsic fluorescence was increased and Far-UV CD spectra were changed accordingly. Relative to the wild type enzyme, 0.164, 0.195 remaining activity and lack of activity was shown with the zymographic assay for N∆89, C∆274 and N∆89C∆274 variants, respectively. The diminished enzyme activity and structural changes suggested a reorientation of microenvironments interactions including cation-π interactions around structural elements toward lowering regional mobility. Constructing applicable truncated cABC I with improved features could be regarded as a strategy to regain new possible functional advantages over the full length enzyme.


Asunto(s)
Proteínas Bacterianas/química , Condroitina ABC Liasa/química , Proteínas Bacterianas/genética , Condroitina ABC Liasa/genética , Estabilidad de Enzimas , Escherichia coli/genética , Cinética , Modelos Moleculares , Mutación , Conformación Proteica , Proteus vulgaris/enzimología
12.
Appl Biochem Biotechnol ; 186(2): 358-370, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29627885

RESUMEN

Removal of chondroitin sulfate glycosaminoglycan (GAG) chains with chondroitinase ABC I (chABC I) in CNS injury models promotes both saxon regeneration and plasticity. It has been suggested that direct interaction between an aromatic pair appears to contribute about - 1.3 kcal/mol to the stability of a folded protein, so introducing an aromatic pair by point mutation might increase the enzyme activity and thermal stability as in the case of mesophilic xylanase, although using this approach destabilized T4 lysozyme. In this study, we used site-directed mutagenesis to investigate the effect of new aromatic pairs on activity and stability of chABC I. We replaced Ile295, Ser581, and Gly730 adjacent to pre-existing aromatic residues with Tyr to obtain new aromatic pairs, i.e., Tyr295/His372, Tyr576/Tyr581, and Tyr623/Tyr730. Results showed that Km values of S581Y and G730Y variants decreased relative to wild-type enzyme while their catalytic efficiency (kcat/Km) increased but I295Y variant was inactive. Also, long-term and thermal stability of the active mutants was decreased. Fluorescence and circular dichroism studies showed that these mutations resulted in a more flexible enzyme structures: a finding which was confirmed by thermal and limited proteolytic studies. In conclusion, the activity of chABC I can be improved by introducing appropriate aromatic pairs at the enzyme surface. This approach did not provide any promising results regarding the enzyme stability.


Asunto(s)
Condroitina ABC Liasa/química , Condroitina ABC Liasa/metabolismo , Catálisis , Condroitina ABC Liasa/genética , Dicroismo Circular , Estabilidad de Enzimas , Mutagénesis Sitio-Dirigida , Estructura Secundaria de Proteína , Espectrometría de Fluorescencia , Espectrofotometría Ultravioleta , Termodinámica
13.
Enzyme Microb Technol ; 105: 38-44, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28756859

RESUMEN

Chondroitinase ABC I (ChABC I) has been shown to depolymerize a variety of glycosaminoglycan substrates and promote regeneration of damaged spinal cord. However, to date, intrathecal delivery methods have been suboptimal largely due to enzyme instability which necessitates repeated administration to the injured loci. Among the aromatic amino acids, tyrosine has been shown to be more effective in creation of stable clusters and further stabilize of the proteins. Bioinformatics approaches have been used to examine the effect of an extra aromatic cluster at the surface of ChABC I. In this study two amino acids i.e., Asn806 and Gln810 were mutated to tyrosine and to alanine as negative control. In this way, four variants i.e., N806Y/Q810Y, N806A/Q810Y, N806Y/Q810A and N806A/Q810A were created. The results showed that N806Y/Q810Y mutation improved both activity and thermal stability of the enzyme while Ala substitution reduced the enzyme activity and destabilized it. Structural analysis of mutants showed an increase in intrinsic fluorescence intensity and secondary structure content of N806Y/Q810Y mutant when compared to the wild type enzyme indicating a more rigid structure of this variant. Moreover, the N806Y/Q810Y enzyme displayed a remarkable resistance against trypsin degradation with a half-life (t1/2) of 45.0min versus 32.5min of wild-type. In conclusion, the data revealed that structural features and activity of ChABC I can be improved by introducing appropriate aromatic clusters at the surface of the enzyme.


Asunto(s)
Condroitina ABC Liasa/química , Condroitina ABC Liasa/metabolismo , Sustitución de Aminoácidos , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Condroitina ABC Liasa/genética , Estabilidad de Enzimas , Cinética , Modelos Moleculares , Mutagénesis Sitio-Dirigida , Ingeniería de Proteínas , Estructura Secundaria de Proteína , Proteus vulgaris/enzimología , Proteus vulgaris/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Espectrometría de Fluorescencia
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