Objective: Formin-2 (Fmn2) mutant mice produce oocytes with meiosis I arrest. Our aim was to describe the human FORMIN-2 (FMN2) gene and to identify DNA seq uence polymorphisms in patients with unexplained infertility...Objective: Formin-2 (Fmn2) mutant mice produce oocytes with meiosis I arrest. Our aim was to describe the human FORMIN-2 (FMN2) gene and to identify DNA seq uence polymorphisms in patients with unexplained infertility and multiple failed IVF cycles. Design: Institutional review board-approved observational case-co ntrol study. Setting: Infertility center and university hospital. Patient(s): Si xty-two fertile controls and seven subjects with unexplained infertility. Inter vention(s): BLASTP (www.ncbi.nlm.nih.gov) was used to map the genomic DNA and co mplementary DNA sequence of FMN2. Genomic DNA was extracted from blood leukocyte samples. The polymerase chain reaction was used to amplify FMN2 gene exons for analysis by denaturing gradient gel electrophoresi s. Main Outcome Measure(s): Characterization of the FMN2 gene and identification of fragment melting polymorphisms (FMPs). Result(s): FMN2 includes 411,960 base pairs (bp) of DNA with 6,204 bp in 18 exons. There was no difference in FMN2 FM P allele frequencies between the controls and subjects. One patient was homozygo us for one FMP. Conclusion(s): The human FMN2 gene is conserved between evolutio narily diverse vertebrates. It is likely that FMN2 has the same function as Fmn2 in the mouse (i.e., maintenance of the meiotic spindle). Prospective identifica tion of patients with meiosis I arrest is necessary to determine whether FMN2 mu tations are a cause of unexplained infertility.展开更多
AzoR is a homodimeric,flavin mononucleotide（FMN）-containing,NADH-dependent azoreductase from Escherichia coli.In this paper,we investigated the effect of the concentration of both AzoR and R59 G on the spectral beha...AzoR is a homodimeric,flavin mononucleotide（FMN）-containing,NADH-dependent azoreductase from Escherichia coli.In this paper,we investigated the effect of the concentration of both AzoR and R59 G on the spectral behavior of the bound FMN using two-dimensional fluorescence correlation spectra.Two cross peaks（530,490） and（580,530） were observed from the dilution-induced 2D asynchronous correlation map of wt AzoR,while only one cross peak appeared at（600,530） for R59 C mutant.This result indicated that the mutation at site 59 influenced the formation of dilution-induced intermediates.The specific activity of both AzoR and R59 G mutant was unaffected by dilution when the enzyme concentration is below 1 μmol/L,which suggested that no significant dissociation of FMN occurred at low concentrations.Additionally,in order to explore the origin of these intermediates,we carried out a2 D correlation analysis using excitation wavelength-dependent fluorescence emission spectroscopy.The results showed that there coexisted two types of FMN that emitted fluorescence at 530 nm and 500 nm,respectively.Taken together,these results suggested that the 2D method is a very powerful method to identify the heterogeneous distribution of the bound FMN in solution.展开更多
Four arsenic-resistance genes(arsB,arsC,arsH,arsR) have been discovered in Acidithiobacillus ferrooxidans.Their gene sequences have been identified and three different arsenic-resistance mechanisms have been elucidate...Four arsenic-resistance genes(arsB,arsC,arsH,arsR) have been discovered in Acidithiobacillus ferrooxidans.Their gene sequences have been identified and three different arsenic-resistance mechanisms have been elucidated.However,the function of the arsH gene in At.ferrooxidans remains unclear.In order to evaluate the function of the arsH gene,we cloned it and expressed it in Escherichia coli.The protein was purified and its relative molecular mass was determined by SDS-PAGE(Sodium dodecyl sulfate-polyacrylamide gel electrophoresis).The results indicated that the relative molecular mass of the purified ArsH was approximately 29 kDa.The purified protein ArsH from E.coli BL21 was a flavoprotein that oxidized in vitro NADPH with an optimal pH of 6.4.展开更多
文摘Objective: Formin-2 (Fmn2) mutant mice produce oocytes with meiosis I arrest. Our aim was to describe the human FORMIN-2 (FMN2) gene and to identify DNA seq uence polymorphisms in patients with unexplained infertility and multiple failed IVF cycles. Design: Institutional review board-approved observational case-co ntrol study. Setting: Infertility center and university hospital. Patient(s): Si xty-two fertile controls and seven subjects with unexplained infertility. Inter vention(s): BLASTP (www.ncbi.nlm.nih.gov) was used to map the genomic DNA and co mplementary DNA sequence of FMN2. Genomic DNA was extracted from blood leukocyte samples. The polymerase chain reaction was used to amplify FMN2 gene exons for analysis by denaturing gradient gel electrophoresi s. Main Outcome Measure(s): Characterization of the FMN2 gene and identification of fragment melting polymorphisms (FMPs). Result(s): FMN2 includes 411,960 base pairs (bp) of DNA with 6,204 bp in 18 exons. There was no difference in FMN2 FM P allele frequencies between the controls and subjects. One patient was homozygo us for one FMP. Conclusion(s): The human FMN2 gene is conserved between evolutio narily diverse vertebrates. It is likely that FMN2 has the same function as Fmn2 in the mouse (i.e., maintenance of the meiotic spindle). Prospective identifica tion of patients with meiosis I arrest is necessary to determine whether FMN2 mu tations are a cause of unexplained infertility.
基金fund by sub-project of National Science and Technology Major Project on Water Pollution Prevention and Control(No.2012ZX07203-003-Z04)supported by the Fundamental Research Funds for the Central Universities(No. ZYGX2012J112)
文摘AzoR is a homodimeric,flavin mononucleotide（FMN）-containing,NADH-dependent azoreductase from Escherichia coli.In this paper,we investigated the effect of the concentration of both AzoR and R59 G on the spectral behavior of the bound FMN using two-dimensional fluorescence correlation spectra.Two cross peaks（530,490） and（580,530） were observed from the dilution-induced 2D asynchronous correlation map of wt AzoR,while only one cross peak appeared at（600,530） for R59 C mutant.This result indicated that the mutation at site 59 influenced the formation of dilution-induced intermediates.The specific activity of both AzoR and R59 G mutant was unaffected by dilution when the enzyme concentration is below 1 μmol/L,which suggested that no significant dissociation of FMN occurred at low concentrations.Additionally,in order to explore the origin of these intermediates,we carried out a2 D correlation analysis using excitation wavelength-dependent fluorescence emission spectroscopy.The results showed that there coexisted two types of FMN that emitted fluorescence at 530 nm and 500 nm,respectively.Taken together,these results suggested that the 2D method is a very powerful method to identify the heterogeneous distribution of the bound FMN in solution.
基金Project(50621063) supported by the National Natural Science Foundation of ChinaProject(2004CB619201) supported by the National Basic Research Program of China
文摘Four arsenic-resistance genes(arsB,arsC,arsH,arsR) have been discovered in Acidithiobacillus ferrooxidans.Their gene sequences have been identified and three different arsenic-resistance mechanisms have been elucidated.However,the function of the arsH gene in At.ferrooxidans remains unclear.In order to evaluate the function of the arsH gene,we cloned it and expressed it in Escherichia coli.The protein was purified and its relative molecular mass was determined by SDS-PAGE(Sodium dodecyl sulfate-polyacrylamide gel electrophoresis).The results indicated that the relative molecular mass of the purified ArsH was approximately 29 kDa.The purified protein ArsH from E.coli BL21 was a flavoprotein that oxidized in vitro NADPH with an optimal pH of 6.4.
