D-mannose has many functional activities and is widely used in food, medicine, agriculture and other industries. D-mannitol oxidase that can efficiently convert D-mannitol into D-mannose has potential application in the enzymatic preparation of D-mannose. A D-mannitol oxidase (PsOX) was found from Paenibacillus sp. HGF5. The similarity between PsOX and the D-mannitol oxidase (AldO) from Streptomyces coelicolor was 50.94%. The molecular weight of PsOX was about 47.4 kDa. A recombinant expression plasmid pET-28a-PsOX was constructed and expressed in Escherichia coli BL21(DE3). The Km and kcat/Km values of PsOX for D-mannitol were 5.6 mmol/L and 0.68 L/(s·mmol). Further characterization of PsOX showed its optimal pH and temperature were 7.0 and 35 ℃, respectively, while its enzyme activity could be stably remained below 60 ℃. The molar conversion rate of 400 mmol/L D-mannitol by PsOX was 95.2%. The whole cells of PsOX and AldO were used to catalyze 73 g/L D-mannitol respectively. The reaction catalyzed by PsOX completed in 9 h and 70 g/L D-mannose was produced. PsOX showed a higher catalytic efficiency compared to that of AldO. PsOX may facilitate the enzymatic preparation of D-mannose as a novel D-mannose oxidase.
Recombinant Proteins/metabolism , Paenibacillus/metabolism , Mannose/metabolism , Escherichia coli/metabolism , Mannitol/metabolism
BACKGROUND: Proper fluid resuscitation can relieve visceral damage and improve survival in severely burned patients. This study compared the effectiveness of resuscitation with 400mEq/L hypertonic saline (HS) and sodium lactate Ringer's solution (LR) in rats with kidney injury caused by burn trauma. METHODS: Rats (Sprague-Dawley) underwent burn injury and were randomized into sham, LR, and HS groups. Samples from the kidney were assayed for water content ratio, histopathology, and oxidative stress (superoxide dismutase (SOD) and malondialdehyde (MDA)). Serum sodium, renal function (creatinine and cystatin (Cys)-C), and inflammatory response (tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and high mobility group protein box (HMGB)-1) were also examined as serum markers. RESULTS: Hypertonic saline resuscitation reduced the renal water content ratio and improved renal histopathology caused by severe burns. This effect was accompanied by reductions in serum creatinine and Cys-C as well as TNF-α, IL-1ß, and HMGB1. Serum sodium concentration and SOD activity were increased, whereas MDA content was decreased in the kidney tissue of the HS group. CONCLUSIONS: The data indicate that 400mEq/L HS solution reduces hyponatremia and renal edema, inhibits the release of inflammatory mediators, and alleviates oxidative stress injury, thus protecting against kidney injury induced by severe burns.
Acute Kidney Injury/metabolism , Burns/metabolism , Fluid Therapy/methods , Kidney/drug effects , Saline Solution, Hypertonic/pharmacology , Acute Kidney Injury/immunology , Animals , Burns/immunology , Creatinine/metabolism , Cystatin C/drug effects , Cystatin C/metabolism , Edema/immunology , Edema/metabolism , HMGB1 Protein/drug effects , HMGB1 Protein/immunology , Hyponatremia/metabolism , Interleukin-1beta/drug effects , Interleukin-1beta/immunology , Kidney/metabolism , Malondialdehyde/metabolism , Oxidative Stress/drug effects , Random Allocation , Rats , Resuscitation , Ringer's Lactate/pharmacology , Sodium/metabolism , Superoxide Dismutase/drug effects , Superoxide Dismutase/metabolism , Tumor Necrosis Factor-alpha/drug effects , Tumor Necrosis Factor-alpha/immunology
To research the pharmacokinetic of Danshensu in brain via microdialysis method and automated blood technique. A microdialysis probe was inserted into the left lateral ventricle, and then dialysate samples and blood samples were continuously collected after iv Danshensu. LC-MS/MS was used to determinate for Danshensu in the dialysate samples. The in vivo recovery was used for the calibration of probe. WinNonlin was used for analyzing all pharmacokinetic data. Pharmacokinetic parameters of DSS in blood and in brain showed that Ke, t1/2,, AUC0-t, MRT were 0.04, 0.018 min(-1), 16.64, 58.76 min, 812.59, 51.19 min x mg x L(-1), 15.28, 79.97 min, respectively. The results were indicated that the study was successfully established LC-MS/MS detection method for Danshensu. Microdialysis combined with automated blood technique could better reflect the dynamic characteristics of Danshensu in the rat brain, and it provides a new perspective for pharmacokinetic study.
Brain/metabolism , Lactates/pharmacokinetics , Animals , Brain Chemistry , Lactates/blood , Male , Microdialysis , Rats , Rats, Sprague-Dawley
To research the pharmacokinetic of Danshensu in brain via microdialysis method and automated blood technique. A microdialysis probe was inserted into the left lateral ventricle, and then dialysate samples and blood samples were continuously collected after iv Danshensu. LC-MS/MS was used to determinate for Danshensu in the dialysate samples. The in vivo recovery was used for the calibration of probe. WinNonlin was used for analyzing all pharmacokinetic data. Pharmacokinetic parameters of DSS in blood and in brain showed that Ke, t1/2,, AUC0-t, MRT were 0.04, 0.018 min(-1), 16.64, 58.76 min, 812.59, 51.19 min x mg x L(-1), 15.28, 79.97 min, respectively. The results were indicated that the study was successfully established LC-MS/MS detection method for Danshensu. Microdialysis combined with automated blood technique could better reflect the dynamic characteristics of Danshensu in the rat brain, and it provides a new perspective for pharmacokinetic study.
Animals , Male , Rats , Brain , Metabolism , Brain Chemistry , Lactates , Blood , Pharmacokinetics , Microdialysis , Rats, Sprague-Dawley
