保卫细胞质膜转运蛋白与气孔运动关系研究

近些年研究表明，保卫细胞质膜上存在多种转运蛋白，这些特殊结构是保卫细胞离子出入，信号导等生理过程的重要调控机构。研究保卫细胞质膜转运蛋白特性、功能与气孔运动的关系对于认识气孔运动机理，调控气孔运动等有重要意义。     

小麦幼苗抗冻蛋白的分离及其抗氧化活性的研究

通过低温处理小麦幼苗来诱导抗冻蛋白的表达，采用DEAE-52和丙烯葡聚糖S300柱层析的方法分离了小麦幼苗中的抗冻蛋白，并对所分离的蛋白进行了SDS-PAGE分析，而且对其抗氧化活性也进行了初步研究，结果表明：低温处理可以诱导小麦幼苗抗冻性，从小麦幼苗中分离到一类热稳定的抗冻蛋白，其分子质量约为20～34ku，当浓度为10g／L时，测得其热滞活性为0．3℃．此类蛋白对羟基自由基活性有一定的抑制作用，表明它具有抗氧化活性．     

Mathematical and numerical model to study two-dimensional free flow isoelectric focusing

Even though isoelectric focusing (IEF) is a very useful technique for sample concentration and separation, it is challenging to extract separated samples for further processing. Moreover, the continuous sample concentration and separation are not possible in the conventional IEF. To overcome these challenges, free flow IEF (FFIEF) is introduced in which a flow field is applied in the direction perpendicular to the applied electric field. In this study, a mathematical model is developed for FFIEF to understand the roles of flow and electric fields for efficient design of microfluidic chip for continuous separation of proteins from an initial well mixed solution. A finite volume based numerical scheme is implemented to simulate two dimensional FFIEF in a microfluidic chip. Simulation results indicate that a pH gradient forms as samples flow downstream and this pH profile agrees well with experimental results validating our model. In addition, our simulation results predict the experimental behavior of pI markers in a FFIEF microchip. This numerical model is used to predict the separation behavior of two proteins (serum albumin and cardiac troponin I) in a two-dimensional straight microchip. The effect of electric field is investigated for continuous separation of proteins. Moreover, a new channel design is presented to increase the separation resolution by introducing cross-stream flow velocity. Numerical results indicate that the separation resolution can be improved by three folds in this new design compare to the conventional straight channel design.     

葡萄籽原花青素对缺血再灌注肝脏氧化损伤和细胞凋亡的影响

目的：探讨葡萄籽原花青素对大鼠肝缺血再灌注损伤的抗氧化作用、凋亡相关蛋白Bcl-2和Bax表达的影响。方法：SD雄性大鼠30只,复制肝缺血再灌注损伤模型。随机分为：假手术组;HIRI模型组;葡萄籽原花青素预处理（GSPE）组（160 mg/kg）,每组10只。于再灌注后3 h检测肝组织谷胱甘肽过氧化物酶（GSH-Px）、超氧化物歧化酶（SOD）、丙二醛（MDA）含量及血清谷丙转氨酶（ALT）、谷草转氨酶（AST）的含量;光镜下比较各组肝组织形态学的变化;免疫组化法检测GSPE对凋亡相关蛋白Bcl-2,Bax表达的影响。结果：与HIRI模型组比较,GSPE预处理组血清ALT、AST水平明显降低（P〈0.05）;肝组织GSH-Px、SOD的活性明显升高（P〈0.05）,而MDA含量下降（P〈0.05）。光镜下GSPE预处理组肝细胞损伤程度较模型组明显减轻;免疫组化结果显示,GSPE预处理组肝组织Bcl-2蛋白的表达量较模型组明显增多,而Bax蛋白的表达量则较模型组明显减少。结论：GSPE对缺血再灌注肝脏具有一定的抗氧化损伤和抗凋亡的作用。     

蓝绿温和胶电泳及其在植物类囊体膜蛋白组研究中的应用

蓝绿温和胶电泳（BN-PAGE）以其温和、高效的优势,越来越多的被应用于植物研究领域。而类囊体作为植物光合作用的重要场所,在植物蛋白质组学研究中倍受关注。着重介绍了BN-PAGE在植物类囊体蛋白组学研究方面的应用,同时对BN-PAGE在此领域的应用趋势进行了探讨。     

热应激蛋白用于诊断和评价过度训练的研究进展

运动应激可通过内外感受器、传入神经通路或内分泌系统支配、调节身体的适应性恢复过程。当运动员承受不了运动应激引起的各种非特异性变化的总和时就可能出现过度训练。研究发现,应激时引起应激蛋白（heat shock proteins,Hsps）的变化与机体运动疲劳和细胞损伤及修复程度有关,且热应激蛋白与机体内细胞内稳态密切相关,提示热应激蛋白和过度训练存在一定的联系。过度训练导致的热应激蛋白的变化可能是机体的内源性保护机制。故本文在综述运动应激、过度训练和热应激蛋白变化间联系的基础上,探讨并分析了骨骼肌Hsps对运动应激和过度训练的表达及其相关机制。     

FABP2 gene polymorphism and metabolic syndrome in elderly people of croatian descent

Introduction:

Metabolic syndrome (MetS) is a multifactorial disorder in which dyslipidemia plays an important role. Fatty acid-binding protein 2 (FABP 2) is responsible for transport of free fatty acids in the intestinal endothelium cells. FABP2-genetic variants might affect plasma lipid concentrations and intracellular lipid transport. The aim of this study was to investigate the association between FABP2 Ala54Thr genetic polymorphism and metabolic syndrome and some biochemical and anthropological parameters in elderly subjects.

Materials and methods:

This cross-sectional study included 140 men and 176 women older than 70 years. Fasting serum concentration of glucose, lipid parameters, total proteins and C-reactive protein were determined by standardized methods. Presence (MetS(+)) or absence (MetS(−)) of MetS was determined according to criteria of the International Diabetes Federation. FABP2 genetic polymorphism Ala54Thr (rs1799883) was genotyped with PCR-RFPL.

Results:

The genotype frequencies for Ala/Ala, Ala/Thr and Thr/Thr genotype were 60, 36 and 6 in MetS(−), and 131, 70 and 13 in MetS(+), respectively, without statistical significance (P = 0.567). Ala/Ala genotype was a subgroup of non-carriers, while Ala/Thr and Thr/Thr genotypes were Thr54-carriers. Median triglyceride concentration was significantly lower in carriers then in non-carriers for whole MetS(+) group (P = 0.050); there were no significant difference between men with MetS (P = 0.144), but there was a difference between women with MetS (P = 0.020). T-test showed that mean HDL cholesterol concentrations in MetS(+) group for Thr54-carriers was significantly higher in whole group (P = 0.001), and for both genders (men P = 0.039; women P = 0.004) as compared to non-carriers.

Conclusions:

FABP2 genetic polymorphism is associated with lower triglyceride and higher HDL-cholesterol concentrations in elderly subjects with MetS. This genetic variation might be a useful marker for understanding dyslipidemia in MetS.     

Water-dispersed bone morphogenetic protein nanospheres prepared by co-precipitation method

A modified complex coacervation-co-precipitation method was used to prepare bone morphogenetic protein(BMP)-loaded nanospheres. Three natural polymers were used as packing materials to obtain nanoscale delivery device for BMP,in the presence of phosphatidylcholine functioning as stabilizer. Positively charged polysaccharide, N,N-diethylaminoethyl dex-tran (DEAE-dextran) tended to form stable, uniform and smaller size particles carrying BMP. Negatively charged bovine serumalbumin (BSA) induced precipitation of the produced BMP particles due to its weak interaction with BMP molecules, although itproduced nanosized BMP spheres. While collagen, a weakly positively charged protein shaped larger particles due to the stronginteraction among themselves. A mechanism of co-precipitation process was also deduced to depict the formation of stablenanospheres.     

Bacterial cryoprotectants

Cold-adapted organisms are known to accumulate cryoprotective substances inside their cells. Glycine betaine is a bacterial cryoprotectant. It is believed to act by stabilizing cellular proteins and membranes at low temperature. M K Chattopadhyay is working as a Scientist at the Centre for Cellular and Molecular Biology, Hyderabad, on cold adaptation in Antarctic bacteria. “There is for me powerful evidence that there is something going on behind it all… It seems as though somebody has fine-tuned nature’s numbers to make the Universe… The impression of design is overwhelming.”     

Differences in dinucleotide frequencies of thermophilic genes encoding water soluble and membrane proteins

The occurrence frequencies of the dinucleotides of genes of three thermophilic and three mesophilic species from both archaea and eubacteria were investigated in this study. The genes encoding water soluble proteins were rich in the dinucleotides of purine dimers, whereas the genes encoding membrane proteins were rich in pyrimidine dimers. The dinucleotides of purine dimers are the counterparts of pyrimidine dimers in a double-stranded DNA. The purine/pyrimidine dimers were favored in the thermophiles but not in the mesophiles, based on comparisons of observed and expected frequencies. This finding is in agreement with our previous study which showed that purine/pyrimidine dimers are positive factors that increase the thermal stability of DNA. The dinucleotides AA, AG, and GA are components of the codons of charged residues of Glu, Asp, Lys, and Arg, and the dinucleotides TT, CT, and TC are components of the codons of hydrophobic residues of Leu, Ile, and Phe. This is consistent with the suitabilities of the different amino acid residues for water soluble and membrane proteins. Our analysis provides a picture of how thermophilic species produce water soluble and membrane proteins with distinctive characters: the genes encoding water soluble proteins use DNA sequences rich in purine dimers, and the genes encoding membrane proteins use DNA sequences rich in pyrimidine dimers on the opposite strand.