Separation and Purification of Antioxidant Peptides from Enzymatically Prepared Scorpion (Buthus martensii Karsch) Protein Hydrolysates

International Journal of Peptide Research and Therapeutics - The purpose of this study was to separate and purify antioxidant peptides from the scorpion (Buthus martensii Karsch) protein...     

Dynamics of Yersinia pestis and Its Antibody Response in Great Gerbils (Rhombomys opimus) by Subcutaneous Infection

Background

Rhombomys opimus (great gerbil) is a reservoir of Yersinia pestis in the natural plague foci of Central Asia. Great gerbils are highly resistant to Y. pestis infection. The coevolution of great gerbils and Y. pestis is believed to play an important role in the plague epidemics in Central Asia plague foci. However, the dynamics of Y. pestis infection and the corresponding antibody response in great gerbils have not been evaluated. In this report, animal experiments were employed to investigate the bacterial load in both the liver and spleen of infected great gerbils. The dynamics of the antibody response to the F1 capsule antigen of Y. pestis was also determined.

Methodology

Captured great gerbils that tested negative for both anti-F1 antibodies and bacterial isolation were infected subcutaneously with different doses (10⁵ to 10¹¹ CFU) of a Y. pestis strain isolated from a live great gerbil during routine plague surveillance in the Junggar Basin, Xinjiang, China. The clinical manifestations, changes in body weight, anal temperature, and gross anatomy of the infected animals were observed. The blood cell count, bacterial load, and anti-F1 antibody titers were determined at different time points after infection using a blood analyzer, plate counts, and an indirect hemagglutination assay, respectively.

Conclusions/Significance

The dynamics of bacterial load and the anti-F1 antibody concentration in great gerbils are highly variable among individuals. The Y. pestis infection in great gerbils could persist as long as 15 days. They act as an appropriate reservoir for plague in the Junggar Basin, which is part of the natural plague foci in Central Asia. The dynamics of the Y. pestis susceptibility of great gerbil will improve the understanding of its variable resistance, which would facilitate the development of more effective countermeasures for controlling plague epidemics in this focus.     

Isolation Purification and Characterization of Antimicrobial Peptides from <Emphasis Type="Italic">Cuminum cyminum</Emphasis> L. Seeds

In this work, antimicrobial peptides from Cuminum cyminum L. seeds were isolated and purified for the first time by 50% ethanol extraction, C18 reverse phase column chromatography and ion exchange chromatography for separation different peptides fraction. Then isolated fractions were characterized by Gel electrophoresis (SDS-PAGE), high-pressure liquid chromatography and the peptides components and molecular weights were determined by liquid chromatography and mass spectrometry. The extracts were tested against some strains of bacteria (E. coli and Staphylococcus aureus) and one strain of fungi (Candida albicans) using well diffusion and broth dilution assays. The extracts from C. cyminum L. seeds demonstrated a high degree of activity (some antibacterial effect) against the bacteria strains and аntifungal activity against the Candida albicans. However, the study indicates that the crude peptide extracts from C. cyminum L. seeds have promising antimicrobial and antioxidant activities that can be harnessed as leads for potential bioactive compounds.     

Reversible methionine sulfoxidation of Mycobacterium tuberculosis small heat shock protein Hsp16.3 and its possible role in scavenging oxidants

Mycobacterium tuberculosis (TB) small heat shock protein Hsp16.3 was found to be a major membrane protein that is most predominantly expressed under oxidative stress and is localized to the thickened cell envelope. Gene knock-out studies indicate that the Hsp16.3 protein is required for TB to grow in its host macrophage cells. The physiological function of Hsp16.3 has not yet revealed. Our analyses via mass spectrometry, conformation-dependent trypsin digestion, nondenaturing pore gradient electrophoresis, ANS-binding fluorescence measurements, and circular dichroism demonstrate that the three and only the three methionine residues (cysteine and tryptophan residues, which can also be readily oxidized by such oxidant as H(2)O(2), are absent in Hsp16.3) can be readily sulfoxidized with H(2)O(2) treatment in vitro, and the methionine sulfoxide can be effectively reduced back to the methionine form. Interconversion between the methionine and methioninesulfoxide has been confirmed by selective oxidation and reduction. The sulfoxidation leads to a small degree of conformational change, which in turn results in a significant decrease of the chaperone-like activity. Data presented in this report strongly implicate that reversible sulfoxidation/desulfoxidation of methionine residues may occur in Hsp16.3, which serves as a way to scavenger reactive oxygen or nitrogen species abundantly present in macrophage cells, thus protecting the plasma membrane and other components of M. tuberculosis allowing their survival in such bacteriocidal hosts.     

Analysis of tandem repeats found in 44 prokaryotic genomes

Genomes contain various types of repetitive sequences. They may be used as probes for seeking genome rearrangements because they are rather free from the natural selection if they are located in the intergenic regions. In this study, we searched for tandem repeats (TRs) in 44 prokaryotic genomes by the color-coding method and sought the signs of genome rearrangements by detailed analysis of the detected TRs. We found 13,542 tandem repeats from 44 prokaryotic genomes in total ranging from several tens to one thousand per genome. The results of statistical analysis show that TRs tend to exist on high base composition bias regions in some genomes. Moreover, we recognized the characteristic distribution patterns of equivalent TR-pairs in 12 genomes, which are expected to indicate the occurrence of whole-genome duplication (WGD) on the genomes. It is demonstrated that TRs could indeed be used for seeking genome rearrangements. Although it has not been made clear at this time whether or not WGD had occurred in prokaryotic genomes, the results of the analyses of equivalent TR-pairs in this study are thought to be evidences of WGD in these genomes.     

One‐step separation and purification of rupestonic acid and chrysosptertin B from Artemisia rupestris L. by high‐speed counter‐current chromatography

Introduction – Artemisia rupestris L. is a well‐known traditional Chinese medicinal plant in Xinjiang. Rupestonic acid is the main active ingredient of A. rupestris L., and has been chosen as a ‘marker compound’ for the chemical evaluation or quality control of A. rupestris L. and its products. Although HSCCC separation method was developed before, the separation was performed with two steps using the same solvent system, which were time‐consuming and waste of the solvents. Objective – To develop a simple HSCCC method for the separation and purification of rupestonic acid in a single run. Methodology – The measurement of partition coefficient (K) was introduced to select the two‐phase solvent system. The simple HSCCC method was established according to the selected solvent system for separation and purification of rupestonic acid. The purity of target compound was test by HPLC and the structure was identified by MS, ¹H NMR and ¹³C NMR. Results – A total of 72.3 mg of rupestonic acid and 53.5 mg of chrysosptertin B with over 95% purity were yielded from 500 mg extracts of Artemisia rupestris L. in one‐step separation. Conclusion – The rupestonic acid was separated in a single run by HSCCC. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis and Characterization of Novel Chickpea Protein Hydrolysate-Vanadium Complexes Having Cell Inhibitory Effects on Lung Cancer A549 Cells Lines

The Protein Journal - Designing new types of drugs with preferred properties against cancer is a great issue for scientists dealing with synthesis and study of biological activity. Several...     

罗勒籽脂肪酸及其对蛋白酪氨酸磷酸酯酶1B(PTP1B)抑制作用的研究

利用索氏提取法提取罗勒籽油,向罗勒籽油加入氢氧化钾甲醇溶液后并用水浴加热,加入正已烷和蒸馏水萃取,上清液即为罗勒籽油中脂肪酸,用气相色谱质谱法(CC/MS)对脂肪酸进行鉴定.共鉴定出了4种脂肪酸,其中α-亚麻酸为62.88％、亚油酸为20.66％、棕榈酸为10.67％、硬脂酸为5.79％.对罗勒籽脂肪酸进行PTP1B的抑制作用研究,结果表明脂肪酸对PTP1B有较强的抑制作用,其IC50为11.12 μg/mL.该研究为深入研究罗勒籽的药理作用提供了科学依据.