Based on a detailed study of the solubility of serum albumin, a procedure for its purification by selective ammonium sulphate precipitation has been developed. Using buffalo serum, first extraneous proteins were precipitated by making the serum 2.26 M saturated with ammonium sulphate at pH 7.0 and then albumin was precipitated from the supernatant at 1.9 M ammonium sulphate concentration at pH 4.2. The overall yield of serum albumin thus isolated was about 55% with a purity of 97%. The protein preparation gave a single nearly symmetrical peak on Sephadex G-100 column and virtually a single band on polyacrylamide gel electrophoresis in the presence and absence of SDS. Buffalo serum albumin has a molecular weight of 69,000 Da. The hydrodynamic properties such as Stoke's radius (3.70 nm), diffusion coefficient (6.03 X 10(-7) cm2/s) and frictional ratio (1.36) obtained by analytical gel chromatography, bilirubin binding characteristics and its interaction with anti-bovine serum albumin antiserum suggest that buffalo serum albumin is very similar to BSA in its molecular properties. 相似文献
People dwelling in different cities of the Potohar region, Pakistan, are mostly dependent on surface water for drinking and domestic use. In an attempt to make available potable, safe water, filtration plants were constructed along with dams in the Potohar region. Water samples from these filtration plants were collected and analyzed for total and faecal coliform bacteria as well as for total viable count. Results showed that bacterial indicators of faecal contamination were numerous and significantly greater than World Health Organization recommended guidelines. Accordingly, antibacterial activity of methanolic and aqueous extracts of different parts of Solanum surrattense were assessed in vitro against waterborne pathogens. Fruits exhibited more antibacterial activities at incubation at 37°C than shoots and roots, which showed lowest Minimum Inhibitory Concentration (MIC) and zones of inhibition. These results suggest that plants offer a great potential for purification of drinking water that needs to be explored further because fruit extract of the aforementioned plant can be of practical use against waterborne pathogens. 相似文献
We studied the utilization of protein-hydrolyzed sweet cheese whey as a medium for the production of β-galactosidase by the
yeasts Kluyveromyces marxianus CBS 712 and CBS 6556. The conditions for growth were determined in shake cultures. The best growth occurred at pH 5.5 and
37°C. Strain CBS 6556 grew in cheese whey in natura, while strain CBS 712 needed cheese whey supplemented with yeast extract. Each yeast was grown in a bioreactor under these
conditions. The strains produced equivalent amounts of β-galactosidase. To optimize the process, strain CBS 6556 was grown
in concentrated cheese whey, resulting in a higher β-galactosidase production. The β-galactosidase produced by strain CBS
6556 produced maximum activity at 37°C, and had low stability at room temperature (30°C) as well as at a storage temperature
of 4°C. At −4°C and −18°C, the enzyme maintained its activity for over 9 weeks.
Received 20 January 1999/ Accepted in revised form 30 April 1999 相似文献
Urease is an important enzyme both in agriculture and medicine research. Strategies based on urease inhibition is critically
considered as the first line treatment of infections caused by urease producing bacteria. Since, urease possess agro-chemical and
medicinal importance, thus, it is necessary to search for the novel compounds capable of inhibiting this enzyme. Several
computational methods were employed to design novel and potent urease inhibitors in this work. First docking simulations of
known compounds consists of a set of arylidine barbiturates (termed as reference) were performed on the Bacillus pasteurii (BP)
urease. Subsequently, two fold strategies were used to design new compounds against urease. Stage 1 comprised of the energy
minimization of enzyme-ligand complexes of reference compounds and the accurate prediction of the molecular mechanics
generalized born (MMGB) interaction energies. In the second stage, new urease inhibitors were then designed by the substitution
of different groups consecutively in the aryl ring of the thiobarbiturates and N, N-diethyl thiobarbiturates of the reference ligands..
The enzyme-ligand complexes with lowest interaction energies or energies close to the calculated interaction energies of the
reference molecules, were selected for the consequent chemical manipulation. This was followed by the substitution of different
groups on the 2 and 5 positions of the aryl ring. As a result, several new and potent diethyl thiobarbiturates were predicted as
urease inhibitors. This approach reflects a logical progression for early stage drug discovery that can be exploited to successfully
identify potential drug candidates. 相似文献
Once characterized as an immune privileged area, recent scientific advances have demonstrated that the central nervous system (CNS) is both immunologically active and a specialized site. The anatomical and cellular features of the brain barriers, the glia limitans, and other superficial coverings of the CNS endow the brain with specificity for immune cell entry and other macro- and micro-elements to the brain. Cellular trafficking via barriers comprised of tightly junctioned non-fenestrated endothelium or tightly regulated fenestrated epithelium results in different phenotypic and cellular changes in the brain, that is, inflammatory versus regulatory changes. Based on emerging evidence, we described the unique ability of the blood cerebrospinal fluid barrier (BCSFB) to recruit, skew, and suppress immune cells. Additionally, we sum up the current knowledge on both cellular and molecular mechanisms governed by the choroid plexus and the cerebrospinal fluid at the BCSFB for immunosurveillance, immunoprotection, and immunopathology. 相似文献
Genetic diversity among 45 Indian mustard (Brassica Juncea L.) genotypes comprising 37 germplasm collections, five advance breeding lines and three improved cultivars was investigated at the DNA level using the random amplified polymorphic DNA (RAPD) technique. Fifteen primers used generated a total of 92 RAPD fragments, of which 81 (88%) were polymorphic. Of these, 13 were unique to accession 'Pak85559'. Each primer produced four to nine amplified products with an average of 6.13 bands per primer. Based on pairwise comparisons of RAPD amplification products, Nei and Li's similarity coefficients were calculated to evaluate the relationships among the accessions. Pairwise similarity indices were higher among the oilseed accessions and cultivars showing narrow ranges of 0.77-0.99. An unweighted pair-group method with arithmetic averages cluster analysis based on these genetic similarities placed most of the collections and oilseed cultivars close to each other, showing a low level of polymorphism between the accessions used. However, the clusters formed by oilseed collections and cultivars were comparatively distinct from that of advanced breeding lines. Genetically, all of the accessions were classified into a few major groups and a number of individual accessions. Advanced breeding lines were relatively divergent from the rest of the accessions and formed independent clusters. Clustering of the accessions did not show any pattern of association between the RAPD markers and the collection sites. A low level of genetic variability of oilseed mustard was attributed to the selection for similar traits and horticultural uses. Perhaps close parentage of these accessions further contributed towards their little diversity. The study demonstrated that RAPD is a simple and fast technique to compare the genetic relationship and pattern of variation among the gene pool of this crop. 相似文献
Paenibacillus alvei NP75, a Gram-positive bacterium, produces two different antimicrobial peptides, paenibacillin N and P, which has potent antimicrobial activity against many clinical pathogens. The synthesis pattern of these antimicrobial peptides by P. alvei NP75 was studied extensively. The results were outstanding in a way that the paenibacillin N was synthesized irrespective of the growth of bacteria (non-ribosomal mediated), whereas paenibacillin P production was carried out by ribosomal mediated. In addition to the antimicrobial peptides, P. alvei NP75 also produces an immunogenic extracellular protease to defend itself from its own antimicrobial peptide, paenibacillin P. Furthermore, this immunogenic protease production was impaired by the addition of protease inhibitor, phenylmethylsulfonyl fluoride (PMSF). The sodium dodecyl sulfate (SDS) treated strain (mutant) failed to produce paenibacillin P, whereas the production of neither paenibacillin N nor the protease was affected by the plasmid curing. The plasmid curing studies that divulge the genes responsible for the synthesis of paenibacillin N and protease were found to be genome encoded, and paenibacillin P was plasmid encoded. We are reporting, first of its kind, the co-production of two different antimicrobial peptides from P. alvei NP75 through non-ribosomal and ribosomal pathways that could be used as effective antibiotics.
Cadmium (Cd) in soil–plant system can abridge plant growth by initiating alterations in root zones. Hydroponics and rhizoboxes are useful techniques to monitor plant responses against various natural and/or induced metal stresses. However, soil based studies are considered more appropriate in order to devise efficient food safety and remediation strategies. The present research evaluated the Cd-mediated variations in elemental dynamics of rhizospheric soil together with in planta ionomics and morpho-physio-biochemical traits of two differentially Cd responsive maize cultivars. Cd-sensitive (31P41) and Cd-tolerant (3062) cultivars were grown in pots filled with 0, 20, 40, 60 and 80 µg/kg CdCl2 supplemented soil. The results depicted that the maize cultivars significantly influenced the elemental dynamics of rhizosphere as well as in planta mineral accumulation under applied Cd stress. The uptake and translocation of N, P, K, Ca, Mg, Zn and Fe from rhizosphere and root cell sap was significantly higher in Cd stressed cv. 3062 as compared to cv. 31P41. In sensitive cultivar (31P41), Cd toxicity resulted in significantly prominent reduction of biomass, leaf area, chlorophyll, carotenoids, protein contents as well as catalase activity in comparison to tolerant one (3062). Analysis of tolerance indexes (TIs) validated that cv. 3062 exhibited advantageous growth and efficient Cd tolerance due to elevated proline, phenolics and activity of antioxidative machinery as compared to cv. 31P41. The cv. 3062 exhibited 54% and 37% less Cd bio-concentration (BCF) and translocation factors (TF), respectively in comparison to cv. 31P41 under highest Cd stress regime. Lower BCF and TF designated a higher Cd stabilization by tolerant cultivar (3062) in rhizospheric zone and its potential use in future remediation plans. 相似文献