Optimized expression of heparin sulfotransferases and their application in sulfation of animal derived heparin / 生物工程学报

Heparin is a very important anticoagulant drug. Currently, heparin is mainly extracted from porcine mucosa. However, animal-derived heparin shows low anticoagulant activity due to the low proportion of the anticoagulant active unit, the GlcNS6S-GlcA-GlcNS6S3S-Ido2S-GlcNS6S pentasaccharide. In this study we proposed an enzymatic strategy to sulfate the animal-sourced heparin to increase the proportion of anticoagulant pentasaccharide and the anticoagulant activity. First, three sulfotransferases HS2ST, HS6ST, and HS3ST were expressed tentatively in Escherichia coli and Pichia pastoris. After measuring the sulfotransferase activity, we confirmed P. pastoris GS115 is the better host for sulfotransferases production. Then, the maltose binding protein (MBP) and thioredoxin (TrxA) were fused separately to the N-terminal of sulfotransferases to increase enzyme solubility. As a result, the yields of HS2ST and HS6ST were increased to (839±14) U/L and (792±23) U/L, respectively. Subsequent sulfation of the animal-sourced heparin with the recombinant HS2ST, HS6ST and HS3ST increased the anticoagulant activity from (76±2) IU/mg to (189±17) IU/mg.

Research on the expression of Caveolin-1 with EGFR mutations in non-small cell lung cancer tissues and its clinical significance / 实用肿瘤学杂志

Objective This study aims to examine expression of Caveolin -1 in non smoking cell lung cancer(NSCLC)and to discusses the relationship between expression of Caveolin -1 and the Epidermal growth factor receptor mutations .Methods Immunohistochemical staining was used to determine the Caveolin -1 ex-pression and ARMS-qPCR was used to measure EGFR mutations in 40 cases of lung cancer tissue .The clinical pathological characteristics and correlations in patients were analyzed .Results The expression of Caveolin -1 in human lung cancer was significantly lower than that in normal lung tissue ,and negatively correlated with EGFR mutations ,which was statistically significant .Conclusion Caveolin -1 expression is negatively correlated with EGFR mutations in non-small cell lung cancer and related to the histologic type .Caveolin-1 may be a molecu-lar target for diagnosis and judgment of NSCLC .