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31.
Stachybotrys microspora is a filamentous fungus that produces various β-glucosidases, of which two have already been characterized. The present study reports on the production of a third one, named bglG, in the presence of d-glucose used as a sole carbon source, and on its subsequent purification and characterization. Although efficiently produced in the presence of d-glucose, bglG continues to be highly inhibited by this sugar. In fact, the addition of d-glucose significantly decreases the glucose formation rates during the hydrolysis of pNPG. This work reports on the effect of various carbohydrates on bglG activity in order to understand the mechanisms adopted by d-glucose to inhibit this enzyme. The findings indicate that bglG is strongly inhibited by d-glucose (44% of the relative activity at 5 mM), d-glucitol (96% of the relative activity), d-mannose (56% of the relative activity), cellobiose and maltose (72% and 71% of the relative activity, respectively). On the other hand, d-galactose, d-fructose, lactose, and sucrose have no effect on bglG activity. Similarly, several isomers, such as 2-acetamido-2-deoxy-d-glucose and 2-deoxy-d-arabino-hexose (2-deoxy-d-glucose) were noted to bring no change on the relative activity of bglG. d-xylose and xylitol, on the other hand, enhanced bglG activity up to 123% and 120% of relative activity, respectively. Accordingly, the configuration, epimerisation, isomerisation, and substitutions played key roles in bglG inhibition. The effect of the combination of iron (the best activator of bglG, 161%) with some of those additives was also investigated. The findings revealed that, while a combination of iron at a concentration of 10 mM with d-glucose resulted in a two-fold decrease in bglG inhibition (84% at 5 mM), iron maintained the same effect with the remainder of the additives being tested. 相似文献
32.
Salehi Jouzani G Seifinejad A Saeedizadeh A Nazarian A Yousefloo M Soheilivand S Mousivand M Jahangiri R Yazdani M Amiri RM Akbari S 《Canadian journal of microbiology》2008,54(10):812-822
The characterization of nematode-effective strains and cry genes in the Iranian Bacillus thuringiensis (Bt) collection (70 isolates) is presented. Characterization was based on PCR analysis using 12 specific primers for cry5, cry6, cry12, cry13, cry14, and cry21 genes encoding proteins active against nematodes, crystal morphology, and protein band patterns as well as their nematicidal activity on root-knot nematode (Meloidogyne incognita) and two free-living nematodes (Chiloplacus tenuis and Acrobeloides enoplus). PCR results with primers for these genes showed that 22 isolates (31.5%) contain a minimum of one nematode-active cry gene. Strains containing the cry6 gene were the most abundant and represent 22.8% of the isolates. Bt strains harboring cry14 genes were also abundant (14.2%). cry21 and cry5 genes were less abundant, found in 4.2% and 2.8% of the strains, respectively. In total, six different nematode-active cry gene profiles were detected in this collection. Four isolates did not show the expected PCR product size for cry5, cry6, and cry21 genes; they might contain potentially novel insecticidal crystal protein genes. Twenty-two Bt isolates containing nematode-active cry genes were selected for preliminary bioassays on M. incognita. Based on these bioassays, four isolates were selected for detailed bioassays. Isolates YD5 and KON4 at 2 x 10(8) CFU/mL concentrations showed 77% and 81% toxicity on M. incognita, respectively. The free-living nematodes C. tenuis and A. enoplus were more susceptible and the highest mortality was observed within 48 h of incubation at all of the concentrations tested. Maximum mortality was recorded for isolates SN1 and KON4 at 2 x 10(8) CFU/mL concentrations and resulted in 68% and 77% adults deaths of C. tenuis and 68% and 72% for A. enoplus, respectively. Our results showed that PCR is a useful technique for toxicity prediction of nematicidal Bt isolates. 相似文献
33.
34.
Muhammad Muzammal Adeel Muhammad Qasim Usman Ali Ashfaq Muhammad Shareef Masoud Mahmood ur Rehman Muhammad Tahir ul Qamar Muhammad Rizwan Javed 《Bioinformation》2014,10(7):454-459
Computational tools occupy the prime position in the analysis of large volume of post-genomic data. These tools have advantage
over the wet lab experiments in terms of high coverage, cost and time. Breast cancer is the most common cancer in females
worldwide. It is a genetically heterogeneous disorder and many genes are involved in the pathway of the disease. Mutations in
metastasis suppressor gene are the major cause of the disease. In this study, the effects of mutations in breast cancer metastasis
suppressor 1gene upon protein structure and function were examined by means of computational tools and information from
databases.This study can be useful to predict the potential effect of every allelic variant, devise new biological experiments and to
interpret and predict the patho-physiological impact of new mutations or non-synonymous polymorphisms. 相似文献
35.
Irum Sidra Andleeb Saadia Ali Amjad Rashid Muhammad Ibrahim Majid Mahnoor 《International journal of peptide research and therapeutics》2021,27(4):2313-2331
International Journal of Peptide Research and Therapeutics - Pseudomonas aeruginosa (P. aeruginosa) is a critical healthcare challenge due to its ability to cause persistent infections and the... 相似文献
36.
Tong L Lin Q Wong WK Ali A Lim D Sung WL Hew CL Yang DS 《Protein expression and purification》2000,18(2):175-181
HPLC6 is the major component of liver-type antifreeze polypeptides (AFPs) from the winter flounder, Pleuronectes americanus. To facilitate mutagenesis studies of this protein, a gene encoding the 37-amino acid mature polypeptide was chemically synthesized and cloned into the Tac cassette immediately after the bacterial ompA leader sequence for direct excretion of the AFP into the culture medium. Escherichia coli transformant with the construct placIQpar8AF was cultured in M9 medium. The recombinant AFP (rAFP) was detected by a competitive enzyme-linked immunosorbent assay (ELISA). After IPTG induction, a biologically active rAFP was expressed. The majority of the rAFP was excreted into the culture medium with only trace amounts trapped in the periplasmic space and cytoplasm. After 18 h of induction, the accumulated rAFP in the culture medium amounted to about 16 mg/L. The excreted AFP was purified from the culture medium by a single-step reverse-phase HPLC. Mass spectrometric and amino acid composition analyses confirmed the identity of the purified product. The rAFP, which lacked amidation at the C-terminal, was about 70% active when compared to the amidated wild-type protein, thus confirming the importance of C-terminal cap structure in protein stability and function. 相似文献
37.
38.
Germ cell transplantation in goats 总被引:19,自引:0,他引:19
Honaramooz A Behboodi E Blash S Megee SO Dobrinski I 《Molecular reproduction and development》2003,64(4):422-428
Transplantation of spermatogonial stem cells provides a unique approach for the study of spermatogenesis and manipulation of the male germ line. This technique may also offer an alternative to the currently inefficient methods of producing transgenic domestic animals. We have recently established the technique of spermatogonial transplantation, originally developed in laboratory rodents, in pigs, and this study was aimed to extend the technique to the goat. Isolated donor testis cells were infused into the seminiferous tubules of anesthetized recipient goats through an ultrasonographically-guided catheter inserted into the rete testis. Donor cells were obtained by enzymatic digestion of freshly collected testes from immature goats (either from the recipients' contralateral testis or from unrelated donors). Prior to transplantation, testis cells were labeled with a fluorescent marker to allow identification after transplantation. Recipient testes were examined for the presence and localization of labeled donor cells at 3-week intervals up to 12 weeks after transplantation. Labeled donor cells were found in the seminiferous tubules of all testes, comprising 10-35% of the examined tubules. Histological examination of the recipient testes did not reveal evident tissue damage, except for limited fibrotic changes at the site of needle insertion. Likewise there were no detectable local or systemic signs of immunologic reactions to the transplantations. These results indicate that germ cell transplantation is technically feasible in immature male goats and that donor-derived cells are retained in the recipient testis for at least three months and through puberty. This study represents the first report of germ cell transplantation in goats. 相似文献
39.
Heevy Abdulkareem Musa Al-Chaqmaqchi Ali Moshfegh Elham Dadfar Josefin Paulsson Moustapha Hassan Stefan H. Jacobson Joachim Lundahl 《PloS one》2013,8(7)
Patients with chronic kidney disease (CKD) have significantly increased morbidity and mortality resulting from infections and cardiovascular diseases. Since monocytes play an essential role in host immunity, this study was directed to explore the gene expression profile in order to identify differences in activated pathways in monocytes relevant to the pathophysiology of atherosclerosis and increased susceptibility to infections. Monocytes from CKD patients (stages 4 and 5, estimated GFR <20 ml/min/1.73 m2) and healthy donors were collected from peripheral blood. Microarray gene expression profile was performed and data were interpreted by GeneSpring software and by PANTHER tool. Western blot was done to validate the pathway members. The results demonstrated that 600 and 272 genes were differentially up- and down regulated respectively in the patient group. Pathways involved in the inflammatory response were highly expressed and the Wnt/β-catenin signaling pathway was the most significant pathway expressed in the patient group. Since this pathway has been attributed to a variety of inflammatory manifestations, the current findings may contribute to dysfunctional monocytes in CKD patients. Strategies to interfere with this pathway may improve host immunity and prevent cardiovascular complications in CKD patients. 相似文献
40.
Ines Hammami Bassem Jaouadi Abir Ben Bacha Ahmed Rebai Samir Bejar Xavier Nesme Ali Rhouma 《Biotechnology and Bioprocess Engineering》2012,17(1):41-49
Bacillus subtilis strain 14B was used to produce a novel antimicrobial peptide (bacteriocin) called Bac 14B. Pure bacteriocin was obtained
after heat and acidic treatments (80°C and pH 4), precipitation by ammonium sulfate, and chromatography on Sephadex G-50 and
Mono Q Sepharose columns. Based on MALDI-TOF mass spectrometry analysis, purified Bac 14B is a monomer protein with a molecular
mass of 20110.13 Da. N-terminal sequencing allowed for the straightforward identification of its first 12 residues, which
were of a pure bacteriocin. It also revealed that this bacteriocin contained a unique sequence, namely M-L-K-A-N-L-Q-N-P-L-N-A,
suggesting the identification of a novel compound. Bac 14B was stable for 1 h at temperatures up to 80°C and pH of 4 ∼ 8.
It also proved sensitive to various proteases, which demonstrated its protein nature. Bac 14B displayed a bacteriolytical
mode of action and a broad range of inhibitory spectra toward Gram-positive and -negative pathogens. Interestingly, based
on conventional agronomic seed vigor parameters, the application of Bac 14B (500 activity units/mL) to various crops revealed
that this bacteriocin was a potent exogenous enhancer of growth that stimulated the seedling vigor of tomatoes and muskmelons.
Compared to those of the control, the germination percentage, shoot weight, shoot height, and root length were all significantly
enhanced in Bac 14B-treated plant seeds. Bac 14B also exhibited effective disinfectant properties against a wide range of
seedborne diseases and significant effects on the control of damping off diseases, particularly at the pregermination stage.
It also proved to be effective against root rot diseases caused by Alternaria solani and other bacterial seedborne pathogens such as wilt diseases. The findings indicate that Bac 14B is the first B. subtilis-produced bacteriocin ever reported to exhibit such promising biological properties. 相似文献