东方法老蛛雌蛛的描述（蜘蛛目：跳蛛科）

报道采自甘肃文县的东方法老蛛雌蛛,为该种雌蛛的首次记述。     

The Saccharomyces cerevisiae SGE1 gene product: a novel drug-resistance protein within the major facilitator superfamily

Several pleiotropic drug sensitivities have been described in yeast. Some involve the loss of putative drug efflux pumps analogous to mammalian P-glycoproteins, others are caused by defects in sterol synthesis resulting in higher plasma membrane permeability. We have constructed a Saccharomyces cerevisiae strain that exhibits a strong crystal violet-sensitive phenotype. By selecting cells of the supersensitive strain for normal sensitivity after transformation with a wild-type yeast genomic library, a complementing 10-kb DNA fragment was isolated, a 3.4-kb subfragment of which was sufficient for complementation. DNA sequence analysis revealed that the complementing fragment comprised the recently sequenced SGE1 gene, a partial multicopy suppressor of gal11 mutations. The supersensitive strain was found to be a sge1 null mutant. Overexpression of SGE1 on a high-copy-number plasmid increased the resistance of the supersensitive strain. Disruption of SGE1 in a wild-type strain increased the sensitivity of the strain. These features of the SGE1 phenotype, as well as sequence homologies of SGE1 at the amino acid level, confirm that the Sge1 protein is a member of the drug-resistance protein family within the major facilitator superfamily (MFS).     

Cerulenin-resistant mutants of Saccharomyces cerevisiae with an altered fatty acid synthase gene

Cerulenin, an antifungal antibiotic produced by Cephalosporium caerulens, is a potent inhibitor of fatty acid synthase in various organisms, including Saccharomyces cerevisiae. The antibiotic inhibits the enzyme by binding covalently to the active center cysteine of the condensing enzyme domain. We isolated 12 cerulenin-resistant mutants of S. cerevisiae following treatment with ethyl methanesulfonate. The mechanism of cerulenin resistance in one of the mutants, KNCR-1, was studied. Growth of the mutant was over 20 times more resistant to cerulenin than that of the wild-type strain. Tetrad analysis suggested that all mutants mapped at the same locus, FAS2, the gene encoding the subunit of the fatty acid synthase. The isolated fatty acid synthase, purified from the mutant KNCR-1, was highly resistant to cerulenin. The cerulenin concentration causing 50% inhibition (IC₅₀) of the enzyme activity was measured to be 400 M, whereas the IC₅₀ value was 15 M for the enzyme isolated from the wild-type strain, indicating a 30-fold increase in resistance to cerulenin. The FAS2 gene was cloned from the mutant. Sequence replacement experiments suggested that an 0.8 kb EcoRV-HindIII fragment closely correlated with cerulenin resistance. Sequence analysis of this region revealed that the GGT codon encoding Gly-1257 of the FAS2 gene was altered to AGT in the mutant, resulting in the codon for Ser. Furthermore, a recombinant FAS2 gene, in which the 0.8 Kb EcoRV-HindIII fragment of the wild-type FAS2 gene was replaced with the same region from the mutant, when introduced into FAS2-defective S. cerevisiae complemented the FAS2 pheno-type and showed cerulenin resistance. These data indicate that one amino acid substitution (Gly Ser) in the subunit of fatty acid synthase is responsible for the cerulenin resistance of the mutant KNCR-1.     

Rational design of peptide-based inhibitors of trypanothione reductase as potential antitrypanosomal drugs

Summary The rational design of ligands for the substrate-binding site of a homology-modelled trypanothione reductase (TR) was performed. Peptides were designed to be selective for TR over human glutathione reductase (GR). The design process capitalized on the proposed differences between the activesites of TR and human GR, subsequently confirmed by the TR crystal structure. Enzyme kinetics confirmed that forT. cruzi TR benzoyl-Leu-Arg-Arg-ß-naphthylamide was an inhibitor (K_i 13.8µM) linearly competitive with the native substrate, trypanothione disulphide, and did not inhibit glutathione reductase.     

一级吸收药物的生物利用度估计的两点法

本文应用系统分析方法,建立了一种一级吸收药物的生物利用度的简便估计的两点法。这种方法,只需测量血管内和血管外给药后的两个相同时点的血药浓度值。不论该药的处置系统是多少室,均能得到较好的结果。这种方法不仅比目前常用的点一点法和点一面法简单,而且结果更精确。     

Screening and molecular dynamics simulation of compounds inhibiting MurB enzyme of drug-resistant Mycobacterium tuberculosis: An in-silico approach

Mycobacterium tuberculosis (MTB) is becoming more and more resistant to drugs and it is a common problem, making current antimicrobials ineffective and highlighting the need for new TB drugs. One of the promising targets for treating MTB is MurB enzymes. This study aimed to identify potential inhibitors of MurB enzymes in M. tuberculosis, as drug resistance among MTB is a significant problem. Attempts are being made to conduct a virtual screening of 30,417 compounds, and thirty-two compounds were chosen for further analysis based on their binding conformations. The selected compounds were assessed for their drug-likeness, pharmacokinetics, and physiochemical characteristics, and seven compounds with binding energy lower than flavin (FAD) were identified. Further, molecular dynamics simulation analysis of these seven compounds found that four of them, namely DB12983, DB15688, ZINC084726167, and ZINC254071113 formed stable complexes with the MurB binding site, exhibiting promising inhibitory activity. These compounds have not been mentioned in any other study, indicating their novelty. The study suggests that these four compounds could be promising candidates for treating MTB, but their effectiveness needs to be validated through in vitro and in vivo experiments. Overall, the findings of this study provide new insight into potential drug targets and candidates for combating drug-resistant MTB.     

Methods to identify protein targets of metal-based drugs

Metal-based anticancer agents occupy a distinct chemical space due to their particular coordination geometry and reactivity. Despite the initial DNA-targeting paradigm for this class of compounds, it is now clear that they can also be tuned to target proteins in cells, depending on the metal and ligand scaffold. Since metallodrug discovery is dominated by phenotypic screenings, tailored proteomics strategies were crucial to identify and validate protein targets of several investigative and clinically advanced metal-based drugs. Here, such experimental approaches are discussed, which showed that metallodrugs based on ruthenium, gold, rhenium and even platinum, can selectively and specifically target proteins with clear-cut down-stream effects. Target identification strategies are expected to support significantly the mechanism-driven clinical translation of metal-based drugs.     

Interaction of chlorpromazine with phospholipid membranes

The interaction of chlorpromazine (CPZ) with artificial membranes (egg-yolk phosphatidylcholine liposomes) has been studied. Measurements of the surface electric potential, which is modified in the presence of the ionized form of the drug, were obtained by electron paramagnetic resonance spectroscopy (EPR) using a positively charged amphiphilic spin-probe. This probe partitions between the aqueous and lipidic phases depending on the surface potential and on the structural state of the membrane. The surface potential was measured as a function of drug concentration in the range where the spectral line-shapes are not affected by the incorporation of the drug. From these experimental results and through an appropriate formalism we obtain information on the binding of the drug to the lipid bilayer and on the ionization of the drug in the lipidic phase. Correspondence to: C. Anteneodo     

Physicochemical characterization and in vitro interaction with brain capillary endothelial cells of artificially monoacylated ribonucleases A

Acylated proteins play a crucial role in cellphysiology because of their increased interaction withmembranes. Their isolation is difficult as aconsequence of their low cellular concentration andtheir chemical preparation is problematic due tosolubility problems. Through the use of reversedmicelles, we produced tens of milligrams of acylatedribonucleases A, chosen as a model, purified them bysemi-preparative high performance liquidchromatography (HPLC) and characterized them by analyticalHPLC, capillary electrophoresis, mass spectrometry, peptide mapping, Edman degradation and enzyme activity. We nextscrutinized the interaction with an in vitro blood–brainbarrier model and demonstrated that palmitoylated andstearoylated ribonucleases A are transported from onecompartment to the other across the cellular monolayer,in contrast to the native enzyme.