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( Yi Han Liu ),( Shu Ai Fan ),( Xiao Guang Liu ),( Zhi Meng Zhang ),( Jian Ling Wang ),( Zheng Xiang Wang ),( Fu Ping Lu ) 한국미생물 · 생명공학회 2014 Journal of microbiology and biotechnology Vol.24 No.7
The stability of Bacillus licheniformis alpha-amylase (BLA) under acid condition was enhanced through direct evolution using the error-prone polymerase chain reaction. One beneficial mutation site, H281I, was obtained in BLA. The specific activity of H281I was 161/352 U/mg, which was 62.6/27.5% higher than that of the wild-type (WT) (99/276 U/mg) at pH 4.5/6.5 and 95°C. The pH optimum for H281I was decreased about 1 unit, whereas no significant changes of optimum temperature and thermostability were observed compared with the wild type (WT). The kcat/Km value of H281I was 1.7-/1.4-fold higher at pH 4.5/6.5, respectively, than that of WT. The structure model analysis indicated that the H281I mutation altered the predicted interaction between the amino acid residues at 281 and 273, thus creating a conducive local environment for substrate binding, as reflected by its decreased Km, and consequently increased the specific activity.
Covalent Immobilization of Penicillin G Acylase onto Fe₃O₄@Chitosan Magnetic Nanoparticles
( Xiao Min Ling ),( Xiang Yu Wang ),( Ping Ma ),( Yi Yang ),( Jie Mei Qin ),( Xue Jun Zhang ),( Ye Wang Zhang ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.5
Penicillin G acylase (PGA) was immobilized on magnetic Fe₃O₄@chitosan nanoparticles through the Schiff base reaction. The immobilization conditions were optimized as follows: enzyme/support 8.8 mg/g, pH 6.0, time 40 min, and temperature 25℃. Under these conditions, a high immobilization efficiency of 75% and a protein loading of 6.2 mg/g-support were obtained. Broader working pH and higher thermostability were achieved by the immobilization. In addition, the immobilized PGA retained 75% initial activity after ten cycles. Kinetic parameters Vmax and Km of the free and immobilized PGAs were determined as 0.113 mmol/min/mg-protein and 0.059 mmol/min/mg-protein, and 0.68 mM and 1.19 mM, respectively. Synthesis of amoxicillin with the immobilized PGA was carried out in 40% ethylene glycol at 25℃ and a conversion of 72% was obtained. These results showed that the immobilization of PGA onto magnetic chitosan nanoparticles is an efficient and simple way for preparation of stable PGA.
Yi-Bin Lan,Xiao-Feng Xiang,Wei-Xi Yang,Bao-Qing Zhu,Hong-Tie Pu,Chang-Qing Duan 한국식품과학회 2020 Food Science and Biotechnology Vol.29 No.12
Berries of six Vitis davidii Foex (spine grape)cultivars (‘Baiputao’, ‘Gaoshan 1’, ‘Gaoshan 2’, ‘Seputao’,‘Miputao’, and ‘Tianputao’) were harvested from a commercialvineyard in Hunan Province in China. Free andbound volatile compounds and fatty acids were analyzedby GC–MS, and amino acids were analyzed by HPLC. ‘Tianputao’ and ‘Miputao’ were characterized by relativelyhigher concentrations of aromatic amino acids and lowerconcentrations of branched-chain amino acids. The majorfree volatile compounds of spine grapes were hexanal, (E)-2-hexenal, 1-hexanol, (E)-2-hexenol, (E)-b-damascenone,and benzeneacetaldehyde. The major glycosidically boundvolatile compounds identified were 1-hexanol, menthol,nerol, 1-butanol, 3-methyl-3-butenol, benzenemethanol, bphenylethanol,eugenol, and guaiacol. (E)-b-damascenone,benzeneacetaldehyde, guaiacol, and eugenol had odoractivity values (OAVs)[1 in all cultivar grapes. Partialleast squares discriminant analysis (PLS-DA) revealed‘Tianputao’ to be distinct from the other cultivars due to itsrelatively higher concentrations of major terpenoids,norisoprenoids, higher alcohols, and aromatic amino acids.
Shotgun analysis on the peritrophic membrane of the silkworm Bombyx mori
( Xiao Wu Zhong ),( Li Ping Zhang ),( Yong Zou ),( Qi Ying Yi ),( Ping Zhao ),( Qing You Xia ),( Zhong Huai Xiang ) 생화학분자생물학회(구 한국생화학분자생물학회) 2012 BMB Reports Vol.45 No.11
The insect midgut epithelium is generally lined with a unique chitin and protein structure, the peritrophic membrane (PM), which facilitates food digestion and protects the gut epithelium. We used gel electrophoresis and mass spectrometry to identify the extracted proteins from the silkworm PM to obtain an in-depth understanding of the biological function of the silkworm PM components. A total of 305 proteins, with molecular weights ranging from 8.02 kDa to 788.52 kDa and the isoelectric points ranging from 3.39 to 12.91, were successfully identified. We also found several major classes of PM proteins, i.e. PM chitin-binding protein, invertebrate intestinal mucin, and chitin deacetylase. The protein profile provides a basis for further study of the physiological events in the PM of Bombyx mori.
Zhao, Yi-Bing,Wang, Jin-Hua,Chen, Xiao-Xiang,Wu, Yu-Zhong,Wu, Qiang Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4
Objective: To compare the clinical efficacy of concurrent chemoradiotherapy, neoadjuvant chemotherapy, and intracavity brachytherapy in comprehensive treatment for young patients with stage Ib2 cervical cancer. Methods: One hundred and twelve young patients with stage Ib2 cervical cancer were enrolled retrospectively in our hospital from January 2003 to June 2005. They were categorized into three groups according to preoperative regimens, including the concurrent chemoradiotherapy group (Group 1, n=38), the neoadjuvant chemotherapy (Group 2, n=49), and the intracavity brachytherapy group (Group 3, n=25). Radical hysterectomy was performed following these regimens. Chemotherapy and radiotherapy were given according to pelvic lymph node metastasis, deep cervical stromal invasion, intravascular cancer emboli, histological grading, vaginal stump and positive surgical margin. Results: The cancer disappearance and superficial muscle invasion rates were statistically significantly better in the concurrent chemoradiotherapy group than in the other two groups (P<0.01). No statistically significant difference was noted in the deep muscle invasion rate, surgical time and intraoperative blood loss among three groups, but significantly more postoperative complications occurred in the concurrent chemoradiotherapy group. The 2-year pelvic recurrence was statistically significantly lower in the concurrent chemoradiotherapy group compared to other two groups, while the 5-year survival was higher. Conclusion: Concurrent chemoradiotherapy is efficacious for young patients with stage Ib2 cervical cancer.
Prediction of postoperative pancreatic fistula using a nomogram based on the updated definition
Cheng-Xiang Guo,Yi-Nan Shen,Qi Zhang,Xiao-Zhen Zhang,Jun-Li Wang,Shun-Liang Gao,Jian-Ying Lou,Ri-Sheng Que,Tao Ma,Ting-Bo Liang,Xue-Li Bai 대한외과학회 2020 Annals of Surgical Treatment and Research(ASRT) Vol.98 No.2
Purpose: The International Study Group on Pancreatic Fistula’s definition of postoperative pancreatic fistula (POPF) has recently been updated. This study aimed to identify risk factors for POPF in patients having pancreaticoduodenectomy (PD) and to generate a nomogram to predict POPF. Methods: Data on 298 patients who underwent PD from March 2012 to October 2017 was retrospectively reviewed and POPF statuses were redefined. A nomogram was constructed using data from 220 patients and validated using the remaining 78 patients. Independent risk factors for POPF were identified using univariate and multivariate analyses. A predictive nomogram was established based on the independent risk factors and was compared with existing models. Results: Texture of the pancreas, size of the main pancreatic duct, portal vein invasion, and definitive pathology were the identified risk factors. The nomogram had a C-index of 0.793 and was internally validated. The nomogram performed better (C-index of 0.816) than the other most cited models (C-indexes of 0.728 and 0.735) in the validation cohort. In addition, the nomogram can assign patients into low- (less than 10%), intermediate- (10% to 30%), and high-risk (equal or higher than 30%) groups to facilitate personalized management. Conclusion: The nomogram accurately predicted POPF in patients having PD.