血红细胞超氧化物歧化酶(SOD)制备工艺的研究初报

本文报告了本实验室设计的由血红细胞自溶液60℃热变性, 乙醇——氯仿法除血红蛋白,旋转蒸发法减压浓缩抽去氯仿、乙醇,硫酸铵分级盐析法沉降SOD,Sepbadex G-75层析提纯SOD等步骤构成的一条成本低、设计合理、简便实用的分离纯化SOD的工艺路线。     

Cloning and sequencing of IS1086, an Alcaligenes eutrophus insertion element related to IS30 and IS4351.

A new insertion sequence (IS), designated IS1086, was isolated from Alcaligenes eutrophus CH34 by being trapped in plasmid pJV240, which contains the Bacillus subtilis sacB and sacR genes. The 1,106-bp IS1086 element contains partially matched (22 of 28 bp) terminal-inverted repeats and a long open reading frame. Hybridization data suggest the presence of one copy of IS1086 in the strain CH34 heavy-metal resistance plasmid pMOL28 and at least two copies in its chromosome. Analysis of the IS1086 nucleotide sequence revealed striking homology with two other IS elements, IS30 and IS4351, suggesting that they are three close members in a family of phylogenetically related insertion sequences. One open reading frame of the Spiroplasma citri phage SpV1-R8A2 B was also found to be related to this IS family but to a lesser extent. Comparison of the G+C contents of IS30 and IS1086 revealed that they conform to their respective hosts (46 versus 50% for IS30 and Escherichia coli and 64.5% for IS1086 and A. eutrophus). The pressure on the AT/GC ratio led to a very different codon usage in these two closely related IS elements. Results suggesting that IS1086 transposition might be activated by some forms of stress are discussed.     

How the Nucleus and Mitochondria Communicate in Energy Production During Stress: Nuclear MtATP6, an Early-Stress Responsive Gene, Regulates the Mitochondrial F1F0-ATP Synthase Complex

A small number of stress-responsive genes, such as those of the mitochondrial F₁F₀-ATP synthase complex, are encoded by both the nucleus and mitochondria. The regulatory mechanism of these joint products is mysterious. The expression of 6-kDa subunit (MtATP6), a relatively uncharacterized nucleus-encoded subunit of F₀ part, was measured during salinity stress in salt-tolerant and salt-sensitive cultivated wheat genotypes, as well as in the wild wheat genotypes, Triticum and Aegilops using qRT-PCR. The MtATP6 expression was suddenly induced 3 h after NaCl treatment in all genotypes, indicating an early inducible stress-responsive behavior. Promoter analysis showed that the MtATP6 promoter includes cis-acting elements such as ABRE, MYC, MYB, GTLs, and W-boxes, suggesting a role for this gene in abscisic acid-mediated signaling, energy metabolism, and stress response. It seems that 6-kDa subunit, as an early response gene and nuclear regulatory factor, translocates to mitochondria and completes the F₁F₀-ATP synthase complex to enhance ATP production and maintain ion homeostasis under stress conditions. These communications between nucleus and mitochondria are required for inducing mitochondrial responses to stress pathways. Dual targeting of 6-kDa subunit may comprise as a mean of inter-organelle communication and save energy for the cell. Interestingly, MtATP6 showed higher and longer expression in the salt-tolerant wheat and the wild genotypes compared to the salt-sensitive genotype. Apparently, salt-sensitive genotypes have lower ATP production efficiency and weaker energy management than wild genotypes; a stress tolerance mechanism that has not been transferred to cultivated genotypes.     

Affinity of Ionic Species of Nucleoside Transport Protein Inhibitors

Abstract

A class of very potent nucleoside transport inhibitors is present in two molecular forms around physiological pH. We investigated whether the monoprotonated or the unionized species of these molecules binds to this camer protein with higher affinity.     

Assessment of Heavy Metal Pollution and Human Health Risks Assessment in Soils Around an Industrial Zone in Neyshabur,Iran

Biological Trace Element Research - Heavy metal pollution of soils in industrial zones continues to attract attention because of its potential human health risks. The present research is an attempt...     

THE EFFECTS OF INJURY PREVENTION WARM-UP PROGRAMMES ON KNEE STRENGTH IN MALE SOCCER PLAYERS

The study investigates the effects of the 11+ and HarmoKnee injury prevention programmes on knee strength in male soccer players. Under-21-year-old players (n=36) were divided equally into: the 11+, HarmoKnee and control groups. The programmes were performed for 24 sessions (20-25 min each). The hamstrings and quadriceps strength were measured bilaterally at 60°·s^-1, 180°·s^-1 and 300°·s^-1. The concentric quadriceps peak torque (PT) of the 11+ increased by 27.7% at 300°·s^-1 in the dominant leg (p<0.05). The concentric quadriceps PT of HarmoKnee increased by 36.6%, 36.2% and 28% in the dominant leg, and by 31.3%, 31.7% and 20.05% at 60°·s^-1, 180°·s^-1 and 300°·s^-1 in the non-dominant leg respectively. In the 11+ group the concentric hamstring PT increased by 22%, 21.4% and 22.1% at 60°·s^-1, 180°·s^-1 and 300°·s^-1, respectively in the dominant leg, and by 22.3%, and 15.7% at 60°·s^-1 and 180°·s^-1, in the non-dominant leg. In the HarmoKnee group the hamstrings in the dominant leg showed an increase in PT by 32.5%, 31.3% and 14.3% at 60°·s^-1, 180°·s^-1 and 300°·s^-1, and in the non-dominant leg hamstrings PT increased by 21.1% and 19.3% at 60°·s^-1 and 180°·s^-1 respectively. The concentric hamstrings strength was significantly different between the 11+ and control groups in the dominant (p=0.01) and non-dominant legs (p=0.02). The HarmoKnee programme enhanced the concentric strength of quadriceps. The 11+ and HarmoKnee programmes are useful warm-up protocols for improving concentric hamstring strength in young professional male soccer players. The 11+ programme is more advantageous for its greater concentric hamstring strength improvement compared to the HarmoKnee programme.     

Occurrence and Characterization of the Bacterial Spot Pathogen Xanthomonas euvesicatoria on Pepper in Iran

We report in this study for the first time the occurrence of bacterial spot of pepper in Iran and both phenotypic and genetic characterization of its causal agent, Xanthomonas euvesicatoria. Pepper plants grown in 15 of 30 surveyed private gardens and commercial fields were infected by the pathogen in Marand County, East Azerbaijan Province, north‐western Iran. The obtained strains of X. euvesicatoria had different amylolytic and pectolytic activities compared with those reported for this species elsewhere. Pathogenicity tests showed that strains isolated from diseased pepper are able to infect tomato, in addition to pepper. Host range of the pathogen was assessed on eight annual plant species including crops and weeds by measuring the population dynamics. The host range assessment showed that in addition to pepper and tomato, known hosts of X. euvesicatoria, the Iranian strains were able to colonize a number of new hosts such as nightshade and common bean. In contrast, none of them were able to build up their population on cowpea, eggplant, bindweed and zucchini. All X. euvesicatoria strains obtained in this study were sensitive to copper sulphate and streptomycin at concentrations higher than 20 and 50 mg/l, respectively. Phylogenetic analyses of the strains using the sequences of gyrB and hrpB genes confirmed their species as X. euvesicatoria. Given a direct commercial trade of fresh solanaceous vegetables between Iran and Turkey, it is hypothesized that the pathogen entered north‐western Iran from eastern parts of Turkey through infected plant materials. Finally, the role of prevention – based on the use of healthy planting materials and resistant and/or tolerant plant varieties – to contain the potential disease epidemics is discussed.