Twin-arginine signal peptide of Bacillus licheniformis GlmU efficiently mediated secretory expression of protein glutaminase

Background: Protein glutaminase specifically deamidates glutamine residue in protein and therefore significantly improves protein solubility and colloidal stability of protein solution. In order to improve its preparation efficiency, we exploited the possibility for its secretory expression mediated by twin-arginine translocation (Tat) pathway in Bacillus licheniformis. Results: The B. licheniformis genome-wide twin-arginine signal peptides were analyzed. Of which, eleven candidates were cloned for construction of expression vectors to mediate the expression of Chryseobacterium proteolyticum protein glutaminase (PGA). The signal peptide of GlmU was confirmed that it significantly mediated PGA secretion into media with the maximum activity of 0.16 U/ml in Bacillus subtilis WB600. A mutant GlmU-R, being replaced the third residue aspartic acid of GlmU twin-arginine signal peptide with arginine by site-directed mutagenesis, mediated the improved secretion of PGA with about 40% increased (0.23 U/ml). In B. licheniformis CBBD302, GlmU-R mediated PGA expression in active form with the maximum yield of 6.8 U/ml in a 25-l bioreactor. Conclusions: PGA can be produced and secreted efficiently in active form via Tat pathway of B. licheniformis, an alternative expression system for the industrial-scale production of PGA.

The Association of Glutaminase (glut) P3 Different Alleles of Trichomonas vaginalis with Infertility in a sample of Iraqi women

Trichomonas vaginalis (T. vaginalis), the etiologic agent of human trichomoniasis, is a flagellated protozoan parasite, has been associated sith advese pregnancy outcomes, HIV transmission, and infertilityh. A total of one hundred and fifty-seven (157) women at childbearing age (14-49 years), were included in the presnt study, eighty six (86) symptomatic fertile while the other seventy-one (71) were infertile with or without sumptoms attending the Gynecology outpatient Department in Al-Emamayn Al-Kadhimayn Medical City, the High Institute of Infertility Diagnosis and Assisted Reproductive Technoligies at Al-Nahrain University in Baghdad, the maternity Teaching hospital, and Dr. Khawer center for infertility and IVF in Erbil province in Iraq. Two vaginal swab specimens were obtained from each of them:; one swab was immediately examined by wet mount microscopy, the other swab for molecular study (DNA extraction and p3 nested PCR). One hundred (100) samples positive in one or more test were identified: 20 (12.7%) infecions were detected by wet mount microscopy, while nested PCR was positive in 100 (63.7%) samples. These positive samples were seguenced and phylogenetic tree were done and, there was no association between the variations in glut (p3) gene of T. vaginalis isolated from infected women (fertile and infertile)