Cloning of the glyceraldehydes 3-phosphate dehydrogenase gene of porphyromonas gingivalis and its expression in E. coli / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To clone the glyceraldehydes 3-phosphate dehydrogenase (GAPDH) gene of Porphyromonas gingivalis (P. gingivalis) and to induce its fusion expression in E. coli.</p><p><b>METHODS</b>GAPDH was obtained by PCR and was inserted into cloning vector pMD-18-T to construct clone recon. Double enzymes digest the recon pMD18-T-GAPDH and the prokaryotic expression vector pET-32a and then connect to get the expressing recon pET-32a-GAPDH. The recombinant expression plasmid which had been confirmed by enzymes digestion was transformed to E. coli competent cells BL21 and induced the expression of GAPDH with isopropyl beta-D-1-thiogalactopyranoside (IPTG) of different density.</p><p><b>RESULTS</b>DNA sequencing showed that the fragment was 99.802% the same to the sequence published in NCBI. Under the best density, IPTG could be highly expressed.</p><p><b>CONCLUSION</b>The GAPDH had been successfully cloned and expressed in E. coli which gets ready for the following experiment to study the immunity of GAPDH and the homologues antibody preparation.</p>

Analysis of outer membrane proteins in various strains of Porphyromonas gingivalis by surface enhanced laser desorption/ionization time-of-flight mass spectrometry / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To analyze the common outer membrane proteins (OMP) from Porphyromonas gingivalis (Pg) by surface enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS) and to provide antigens for the subsequent experiments in screening vaccine for periodontitis therapy.</p><p><b>METHODS</b>Four strains of Pg were cultured under anaerobic conditions. The common OMP was extracted through ultracentrifugation and SELDI-TOF-MS was employed to detect the expressions of proteomes by chip H(50). The data was analyzed by Biomarker Wizard.</p><p><b>RESULTS</b>Four kinds of strains of OMP fingerprint spectrum were obtained. Seventy-one proteins of PgATCC33277, 74 proteins of PgW83, 76 proteins of PgW301 and 72 proteins of Pg381 were captured by chip H(50). Thirteen common proteins were identified according to fingerprint spectrum. There was only 1 of the 13 common proteins identified in NCBI protein bank.</p><p><b>CONCLUSIONS</b>SELDI-TOF-MS has good reproducibility and high sensibility and can be used to identify the common OMP of Pg. The 13 proteins have a potential value in the screening vaccine candidate antigen sites for periodontitis.</p>

A preliminary study on screening for Porphyromonas gingivalis outer membrane protein antigen with two-dimensional liquid phase fractionation and matrix-assisted laser desorption ionization time-of-flight/time-of-flight mass spectrometry / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To screen a variety of Porphyromonas gingivalis (Pg) common outer membrane proteins with two-dimensional liquid phase fractionation (PF2D) and matrix-assisted laser desorption ionization time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF-MS) and provide candidate target antigen for the design of vaccines with cross protection against a variety of Pg.</p><p><b>METHODS</b>The outer membrane proteins of Pg301, PgATCC33277 and PgW83 were extracted through ultracentrifugation, and then they were separated by ProteomeLab PF2D protein fractionation system. After separation, the outer membrane proteins were obtained through comparison, and the primary structure of the proteins was identified by MALDI-TOF/TOF-MS and database.</p><p><b>RESULTS</b>Ninety-nine protein samples out of 3 strains of Pg were obtained after the high performance chromato focusing (HPCF) separation process. B7 fractions of 3 strains of Pg were separated by the reversed-phase high performance liquid chromatography (RP-HPCL) separation process. After comparison of peak and retention time of chromatogram, the 8 common protein peaks of 3 strains of Pg were confirmed. The protein samples were identified by MALDI-TOF/TOF-MS, and one of them was known protein arg-gingipain A.</p><p><b>CONCLUSIONS</b>PF2D protein fractionation system is of good reproducibility and high resolution. A combination of PF2D and MALDI-TOF/TOF-MS can be used to identify the common outer membrane proteins of Pg.</p>

Construction of prokaryotic expression vector of FimA gene from Porphyromonas gingivalis, fusion expression and purification in E. coli BL21(DE3)pLyS / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To clone the FimA gene of fimbriae from Porphyromonas gingivalis (P. gingivalis) and to construct prokaryotic expression vector which was induced in E.coli BL21(DE3)pLyS in the form of fusion protein expression and to identify, purify the product of its expression.</p><p><b>METHODS</b>To clone the FimA gene of fimbriae from P. gingivalis and to construct prokaryotic expression vector pET15b-FimA vector which was transformed into the competent cells of BL21(DE3)pLyS. The expression of fusion protein was induced by isopropyl beta-D-1-thiogalactopyranoside (IPTG). With anti-6xHis Tag monoclonal antibody as the first antibody, the expressed fusion protein was characterized by Western blot and purified by Co(2+)-NTA affinity chromatography.</p><p><b>RESULTS</b>Cloned FimA gene sequences and inserted into expression vector of the FimA sequences were related to the sequence in GenBank database showed 100% homology. IPTG induced and then identified by Western blot showed a fragment of 4.1 x 10(4) has been expressed. Co(2+)-NTA affinity chromatography column was used to obtain high concentrations of FimA purified protein.</p><p><b>CONCLUSION</b>The recombinant prokaryotic expression vector of pET15b-FimA was constructed and was expressed and purified successfully in E. coli BL21 (DE3)pLyS. This study laid the experimental foundation to further prepare for monoclonal antibodies of fimbriae of P. gingivalis and to develop the subunit protein vaccine of prevention of periodontitis.</p>

Sexual hormone levels in semen and germ cell apoptosis / 中华男科学杂志

<p><b>OBJECTIVE</b>To explore the relationship between sexual hormones in semen and germ cell apoptosis in male population.</p><p><b>METHODS</b>Sixty-six infertile patients and thirty fertile males were selected randomly. The levels of folicle stimulating hormone ( FSH), prolactin (PRL), luteinizing hormone (LH), and testosterone (T) in semen were measured by ELISA. Terminal deoxynucleotidyl transferase mediated UTP nick end labeling (TUNEL) was used for the detection of germ cell apoptosis.</p><p><b>RESULTS</b>The levels of FSH, LH, PRL, T in thirty fertile men were (1.63 +/- 0.15) U/L, (2.18 +/- 0.21) U/L, (6.34 +/- 0.30) nmol/L, (1.85 +/- 0.11) nmol/L, respectively, and germ cell apoptosis rate was (4.61 +/- 1.23)%. FSH, LH, PRL, T levels in infertile group were (1.25 +/- 0.18) U/L, (1.76 +/- 0.32) U/L, (5.86 +/- 0.13) nmol/l, (1.45 +/- 0.13) nmol/, respectively, and germ cell apoptosis rate was (18.36 +/- 2.04)%. There were significant differences in all parameters between infertile group and fertile group. The levels of FSH, LH, PRL, T were negatively correlated with germ cell apoptosis rates( r = -0.88, -0.93, -0.90, -0.98). The volume of apoptotic germ cell decreased, and chromatin was compacted to form cell-membrane blebs and apoptotic bodies.</p><p><b>CONCLUSION</b>Low concentration of sexual hormones may increase the apoptosis of germ cells, which can induce male infertility.</p>

Cloning of the RgpAcd gene of Porphyromonas gingivalis and its expression in E. coli / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To clone the catalytic domain gene sequence of RgpAcd of Porphyromonas gingivalis (P. gingivalis) and to induce its fusion expression in E. coli.</p><p><b>METHODS</b>The desired DNA fragment RgpAcd was obtained by PCR and was separately sequenced and identified by inserting into inter-vector pMD18-T vector. The correctly fragment was linked with and cloned into a prokaryotic expression vector pET-15b. The recombinant expression plasmid which had been confirmed by enzymes digestion was transformed to E. coli competent cells BL21 (DE3) and expression of fusion protein was induced by IPTG.</p><p><b>RESULTS</b>A 1 476 bp specific fragment was obtained and DNA sequencing showed that the fragment was consistent with those of the published. After induction with IPTG, a fusion protein of 5 x 10(4) was visualized on SDS-PAGE gel.</p><p><b>CONCLUSION</b>The protein of RgpAcd will be obtained for further study and its protein was correctly expressed in E. coli BL21 cells.</p>