To study the effect of physiological conditions on spidroins, we analyzed NTR1SR2CT module secondary structure, aggregation and silk-formation influenced by different salts (in different concentration intervals). According to the full-length Araneus ventricosus MiSp sequence, NTR1SR2CT module was constructed and expressed in Escherichia coli BL21 (DE3), and the recombinant proteins were purified by denaturation method mediated by 8 mol/L urea. Random coil and helix are the main secondary structures of NTR1SR2CT and could be induced into beta-sheet by drying natively and lyophilization, where methanol can be used as a promoter. Furthermore, potassium and phosphate cations can cause significant NTR1SR2CT protein aggregation and silk-formation. The results could be a basis for the determination of silk-formation mechanism, and also useful for industrialized generation of high performance spider silk-like fibers.
Animals ; Fibroins ; chemistry ; Protein Structure, Secondary ; Salts ; chemistry ; Spiders

Objective To establish the quality standard for Xuanshi Texiao Yaoshui(mainly composed of Radix Sophorae Flavescentis,Cortex Pseudolaricis,etc).Methods Radix Sophorae Flavescentis and Cortex Pseudolaricis were identified by TLC.The content of oxymatrine was determined by HPLC.Symmetry C18 column(4.6 mm? 250 mm,5 ? m)with mobile phase of methanol-water-triethylamine(40:60:0.04)was used.The detective wavelength was 220 nm.Results TLC for Radix Sophorae Flavescentis and Cortex Pseudolaricis was specific .HPLC for oxymatrine had a good separation with other components,and the linear range of oxymatrine was 0.60～ 1.80 ? g and recovery rate was 99.34 %(RSD =0.71 %).Conclusion This method can be used to control the quality of Xuanshi Texiao Yaoshui.

Proton pump inhibitors are H+ /K+-ATPase inhibitors, which can efficiently inhibit gastric acid secretion for a long time. As the latest inhibitory gastric acid drugs, proton pump inhibitors are the best choices for acid-related diseases such as gastroe-sophageal reflux disease, peptic ulcer and gastrointestinal lesions caused by nonsteroidal anti-inflammatory drugs. Proton pump inhibi-tors have significant inhibition to basal gastric acid, night gastric acid and gastric acid secretion caused by gastrin and food stimulation. This article reviewed the pharmacokinetic characteristics of five proton pump inhibitors in domestic market.

Objective T o study the effect of different attentional conditions on the event-related potential (E R P ) com ponents generated by the visual inform ation stim uli related to visual acuity, and provide a theoretical reference for clinical forensic visual objective evaluation. Methods W ith visual acuity opto-types as norm al form of visual inform ation stim uli, 15 volunteers as study subjects w ere supposed to ac-count the visual acuity optotypes under the attentional condition of visual stim uli. Furtherm ore, the sub-jects w ere required to listen to the storytelling carefully under the non-attentional condition of visual stim uli, and after the exam ination, they needed to answ er the story-related questions. A ll the E E G re-sults of tw o different attentional conditions from the subjects w ere recorded by 32 channel E R P system . Results U nder tw o attentional conditions, P 1 and P 300 com ponents w ere evoked by the visual acuity opto-types on supra-threshold and threshold visual acuity levels, w hile only P 1 com ponent w ere evoked by the visual acuity optotypes on sub-threshold levels. In the E R P w aveform s evoked by the visual acuity optotypes on supra-threshold, P 1 and P 300 am plitudes under attentional condition w ere larger than that un-der non-attentional condition. Conclusion A ttentional conditions can influence the detection of visual acuity. P 300 com ponent can be used to distinguish the visual acuity levels w ith supra-threshold and sub-threshold under non-attentional condition.

Objective To investigate the relationship between folate metabolism-related gene polymorphism and fetal congenital defects,and discuss the effect of genetic factors on fetal congenital defects.Methods Retrospective analysis was used to investigate the genotype and gene frequency of 5,1O-methylenetetrahydrofolate reductase (MTHFR) C677T,A1298C gene loci and ethionine synthase reductase (MTRR) A66G gene locus in 132 cases of adverse pregnancy pregnant women (case group) and 150 cases normal pregnant women (control group) at the same period.The statistical differences were analyzed between the levels of their serum folate,vitamin B12 (Vit B12) and homocysteine (HCY).Results In the serum of case group,folate was positively correlated with Vit B12,and was negatively correlated with HCY,only HCY of skeletal system defects(6 cases) was higher (t =3.409,P ＜ 0.05).Comparing genotypes frequency of the MTHFR C677T,A1298C gene loci and MTRR A66G gene locus in case group with control group,the difference above was not statistically significant (P ＞ 0.05).In these three gene loci C/T,A/C and A/G allele frequency with the control group,the difference above was not statistically significant (all P ＞ 0.05).Different genotype combinations of MTHFR C667T and A1298C gene loci in control groups had no statistically different from the control group (P ＞ 0.05),and there was no synergy.Conclusions Maternal folate metabolism-related MTHFR and MTRR genes polymorphisms can affect the metabolic products levels accordingly.However,the correlation between the changes and the genetic mechanism of fetal congenital defects needs more large samples study in depth.

This paper presented the prenatal genetic analysis of a case of mosaic trisomy 2 combined with uniparental disomy 2. The pregnant women underwent non-invasive prenatal testing in Zhuhai Center for Maternal and Child Health Care on February 2019, which indicated an increased number of chromosome 2. Subsequently, amniocentesis was performed at 21 +2 weeks for prenatal diagnosis. No abnormalities were detected through the karyotype analysis of amniotic fluid cells. Chromosome microarray analysis of uncultured amniotic fluid cells revealed a duplication of 2.3 copies in chromosome 2 and 64.3 Mb regions of homozygosity in the 2q21.2q33.1 region. The comparison of single nucleotide information on fetus-parent chromosome 2 showed that the regions of homozygosity of the fetal 2q21.2q33.1 was paternal uniparental isodisomy (2), with the rest of chromosome 2 being paternal uniparental heterodisomy (2).Ultrasound results at 27 +6, 31 +6, and 34 +5 weeks of gestation showed continued exacerbation of fetal growth retardation with placental abnormalities and fetal blood flow spectrum abnormalities. Due to threatened preterm delivery at 35 +3 weeks, The pregnant woman chose to give up the fetus and delivered a stillbirth.

A repetitive DNA fragment, named P1, was amplified by PCR with the full-length Minor Ampullate Spidroin gene sequence of Araneus ventricosus as template. P1 was ligated with pPic3.5 and PKT expression vectors and transferred into GS115 and BL21(DE3) competence cells, respectively. SDS-PAGE and Western blot were used to analyze the recombinant his-tag fusion protein. With expressed in different expression systems, soluble P1 induced proteins could be obtained as the same size. Furthermore, the expression level and purification recovery efficiency were also higher in GS115 than that of BL21(DE3). Additionally, the expression level could be improved after optimizing the incubation and induction conditions of GS115. In this research, Pichia pastoris expression system is more suitable for the native repetitive Gly/Ala-rich spider spidroin gene sequence expression than Escherichia coli system. The data can help the native full-length MiSp gene expression and large-scale exploitation of recombinant of spider silk proteins.
Animals ; Escherichia coli ; genetics ; metabolism ; Fibroins ; biosynthesis ; classification ; genetics ; Genetic Vectors ; genetics ; Pichia ; genetics ; metabolism ; Recombinant Fusion Proteins ; biosynthesis ; Spiders ; classification ; genetics ; metabolism

To provide technical support for spider silk functional modification, we developed a simple and efficient functional platform via intein trans-splicing. Small ubiquitin-related modifier protein (SUMO) was fused to the recombinant spider silk protein (W2CT) by peptide bond via S0 split intein Ssp DnaB trans-splicing, resulting in a protein SUMOW2CT. However, incorporation of exogenous protein led to mechanical property defect and lower fiber yield, and also slowed down the fiber assembly velocity but no obvious differences in supercontraction and chemical resistance when compared with fibers from W2CT (W). SUMO protease digestion showed positive results on the fibers, indicating that the SUMO protein kept its native conformation and bioactive. Above all, this work provides a technical support for spider silk high simply and efficient functionalized modification.
Animals ; Inteins ; Protein Splicing ; Recombinant Proteins ; chemistry ; Silk ; chemistry ; Small Ubiquitin-Related Modifier Proteins ; chemistry ; Spiders ; Trans-Splicing