Preparation and self-cleavage of fusion soluble farnesyl diphosphate synthase in E. coli.

Farnesyl diphosphate synthase (FPPS) is a crucial protein in terpenoid production. However, its industrial application is limited owing to its low solubility in Escherichia coli. In this study, we focused on ispA encoding FPPS and designed a fusion expression system to reduce inclusion body (IB) formation. Among the chosen fusion tags, the GB1-domain (GB1) exhibited the highest ability to solubilize the recombinant protein. Increased rare tRNA abundance not only improved the GB1-FPPS yield but also increased its soluble level. A "one-step" method for the acquisition of soluble FPPS was also considered. By combining GB1-FPPS expression and Tobacco Etch Virus protease (TEVp) cleavage in vivo, a controllable GB1-FPPS "self-cleavage" system was constructed. Overall, this study provides an efficient approach for obtaining soluble forms of FPPS, which show great potential for use in the soluble expression of other homologous diphosphate synthase.

Analysis of the association of ANO3/MUC15, COL4A4, RRBP1, and KLK1 polymorphisms with COPD susceptibility in the Kashi population.

OBJECTIVE: Chronic obstructive pulmonary disease (COPD) is a complex, multifactorial, polygenic disease. The rate of occurrence of COPD in the Kashi population (Uyghur) is significantly higher than that observed nationwide. The identification of COPD-related genes in the Chinese Uyghur population could provide useful insights that could help us understand this phenomenon. Our previous whole-exome sequencing study of three Uyghur families with COPD demonstrated that 72 mutations in 55 genes might be associated with COPD; these included rs15783G > A in the anoctamin 3 (ANO3) gene/mucin 15 (MUC15) gene, rs1800517G > A in the collagen type IV alpha 4 chain (COL4A4) gene, rs11960G > A in the ribosome binding protein 1 (RRBP1) gene, and rs5516C > G in the kallikrein 1 (KLK1) gene. This case-control study aimed to further validate the association of the four mutations with COPD in the Chinese Uyghur population. METHODS: Sanger sequencing was used for the genotyping of four polymorphisms (ANO3/MUC15 rs15783, COL4A4 rs1800517, RRBP1 rs11960, and KLK1 rs5516) in 541 unrelated Uyghur COPD patients and 534 Uyghur healthy controls. We then conducted stratified analyses based on the smoking status and airflow limitation severity, to explore the correlation between selected gene polymorphisms and COPD. RESULTS: ANO3/MUC15 rs15783 and KLK1 rs5516 polymorphisms could significantly reduce COPD risk (p < 0.05), but COL4A4 rs1800517 and RRBP1 rs11960 polymorphisms were not correlated with COPD in the entire population. In a stratified analysis of smoking status, non-smokers with the ANO3/MUC15 rs15783G/G genotype (OR = 0.63, p = 0.032) or COL4A4 rs1800517 allele G (OR = 0.80, p = 0.023) had a reduced risk of COPD. Smokers with the RRBP1 rs11960A/G genotype had a lower risk of COPD (OR = 0.41, p = 0.025). The KLK1 rs5516G > C polymorphism was associated with a decreased risk of COPD (OR < 1, p < 0.05), irrespective of the smoking status of individuals. No significant association with COPD severity was observed in individuals with these four polymorphisms (p > 0.05). CONCLUSION: We identified four previously unreported mutations (ANO3/MUC15 rs15783, COL4A4 rs1800517, RRBP1 rs11960, and KLK1 rs5516) that might decrease the COPD risk in individuals with different smoking statuses in the Chinese Uyghur population. Our findings provide new light for the genetic risk factors associated with the occurrence of COPD.

The rs74794265 SNP of the SREK1 Gene is Associated with COPD in Kashi, China.

BACKGROUND: Kashi city is situated near the Taklamakan desert and has a high incidence rate of chronic obstructive pulmonary disease (COPD). In this study, we aimed to explore the relationship between the SNP of the SREK1 gene locus rs74794265 and the susceptibility to COPD among the Uyghur population in Kashi, XinJiang, China. METHODS: A total of 541 patients with COPD and 534 control subjects were included in this study. Sanger sequencing was used to analyze the SNP of the SREK1 gene locus rs74794265 site. The distribution of genotypes in different genetic models between the case and control group were analyzed by logistic regression analysis after adjusting for age, sex, and smoking history. RESULTS: The SREK1 gene SNP locus rs74794265 included two genotypes, namely, C/C and C/T, of which C/C was the wildtype; The risk of COPD was significantly lower in patients with heterozygous C/T in rs74794265 [p=0.0236, OR=0.3677 (0.1547-0.8742)], and the allele frequency of T was also significantly lower in the patient group [p=0.0245, OR=0.3728 (0.1577-0.8811)]. The heterozygous C/T of rs74794265 among non-smoking COPD patients was significantly lower than other COPD patients [p=0.0298, OR=0.3217 (0.1156-0.8949)], and there was no significant correlation of the heterozygous C/T genotype in smokers. CONCLUSION: We found that the rs74794265 heterozygous C/T genotype significantly reduces the risk of COPD. The C/T genotype is likely a protective factor for COPD in the Kashi region. We speculate that the occurrence of COPD in this area is probably more related to desert climate condition and genetic factors than smoking status.

Prevalence and Risk Factors of Chronic Obstructive Pulmonary Disease in Kashi Region, Northwestern China.

OBJECTIVE: To investigate the prevalence and the risk factors of COPD in the Uyghur population in the Kashi region. METHODS: From August 2018 to March 2019, we recruited participants of Uyghur ethnicity and aged ≥40 years old from the Kashi region using a combined cluster sampling and random sampling method. We collected potential risk factors using questionnaire, and conduced lung function using a portable pulmonary function instrument. RESULTS: A total of 2963 participants were included in this analysis, of whom 1268 were males and 1695 were females. There were 504 participants with COPD, generating a prevalence of 17.01%. With the increase of age, the prevalence of COPD in different genders increased significantly. The results of different regions were χ2= 627.89, p < 0.01, indicating significant differences in the prevalence in different regions. Among them, based on the existing survey data, it is speculated that Shache county has the highest crude prevalence, but the sample size needs to be further expanded. The participants with high age, smoking, lower BMI, high waist circumference, systolic blood pressure, fried cooking and barbecue share more COPD than those who partake of fruits and vegetables in this study. CONCLUSION: The prevalence of COPD among the Uyghur population in the Kashi region is higher than the national rural average. Among them, high age, smoking, low BMI, high waist circumference, high systolic blood pressure, cooking methods that may be stir-fried and deep-fried barbecue are risk factors for COPD, and vegetable and fruit intake may be a protective factor for COPD.

Whole-Exome Sequencing Implicates the USP34 rs777591A > G Intron Variant in Chronic Obstructive Pulmonary Disease in a Kashi Cohort.

Genetic factors are important factors in chronic obstructive pulmonary disease (COPD) onset. Plenty of risk and new causative genes for COPD have been identified in patients of the Chinese Han population. In contrast, we know considerably little concerning the genetics in the Kashi COPD population (Uyghur). This study aims at clarifying the genetic maps regarding COPD susceptibility in Kashi (China). Whole-exome sequencing (WES) was used to analyze three Uyghur families with COPD in Kashi (eight patients and one healthy control). Sanger sequencing was also used to verify the WES results in 541 unrelated Uyghur COPD patients and 534 Uyghur healthy controls. WES showed 72 single nucleotide variants (SNVs), two deletions, and small insertions (InDels), 26 copy number variants (CNVs), and 34 structural variants (SVs), including g.71230620T > A (rs12449210T > A, NC_000,016.10) in the HYDIN axonemal central pair apparatus protein (HYDIN) gene and g.61190482A > G (rs777591A > G, NC_000002.12) in the ubiquitin-specific protease 34 (USP34) gene. After Sanger sequencing, we found that rs777591"AA" under different genetic models except for the dominant model (adjusted OR = 0.8559, 95%CI 0.6568-1.115, p > .05), could significantly reduce COPD risk, but rs12449210T > A was not related to COPD. In stratified analysis of smoking status, rs777591"AA" reduced COPD risk significantly among the nonsmoker group. Protein and mRNA expression of USP34 in cigarette smoke extract-treated BEAS-2b cells increased significantly compared with those in the control group. Our findings associate the USP34 rs777591"AA" genotype as a protector factor in COPD.

SERPINE2 rs16865421 polymorphism is associated with a lower risk of chronic obstructive pulmonary disease in the Uygur population: A case-control study.

BACKGROUND: The present study aimed to investigate the relationship between seven polymorphisms of the serine protease inhibitor-2 (SERPINE2) gene and the risk of chronic obstructive pulmonary disease (COPD) in the Uygur population via a case-control study. METHODS: In total, 440 Uygur patients with COPD were included in the patient group and 384 healthy individuals were recruited in the matched control group. Data on demographic variables, smoking status, occupational dust exposure history and living conditions were collected. Polymorphism analysis was performed for seven loci of the SERPINE2 gene by mass spectrometry. RESULTS: The genotype distribution of rs16865421 showed a significant difference between the patient and control groups (p < 0.05). Participants carrying the rs16865421-AG heterozygous mutant genotype had a lower risk of COPD compared to those with the rs16865421-A allele (odds ratio = 0.68, 95% confidence interval = 0.47-0.98, p = 0.041). However, no such association was found for rs1438831, rs6734100, rs6748795, rs7583463, rs840088 and rs975278. No significant interaction was observed between the genotypes and risk factors. CONCLUSIONS: Polymorphisms of rs16865421-AG carried by the Uygur population may be protective against COPD.

Functionalized CdS quantum dots-based luminescence probe for detection of heavy and transition metal ions in aqueous solution.

Strong luminescence CdS quantum dots (QDs) have been prepared and modified with l-cysteine by a facile seeds-assistant technique in water. They are water-soluble and highly stable in aqueous solution. CdS QDs evaluated as a luminescence probe for heavy and transition metal (HTM) ions in aqueous solution was systematically studied. Five HTM ions such as silver(I) ion, copper(II) ion, mercury(II) ion, cobalt(II) ion, and nickel(II) ion significantly influence the photophysics of the emission from the functionalized CdS QDs. Experiment results showed that the fluorescence emission from CdS QDs was enhanced significantly by silver ion without any spectral shift, while several other bivalent HTM ions, such as Hg(2+), Cu(2+), Co(2+), and Ni(2+), exhibited effective optical quenching effect on QDs. Moreover, an obvious red-shift of emission band was observed in the quenching of CdS QDs for Hg(2+) and Cu(2+) ions. Under the optimal conditions, the response was linearly proportional to the concentration of Ag(+) ion ranging from 1.25 x 10(-7) to 5.0 x 10(-6)molL(-1) with a detection limit of 2.0 x 10(-8)molL(-1). The concentration dependence of the quenching effect on functionalized QDs for the other four HTM ions could be well described by typical Stern-Volmer equation, with the linear response of CdS QDs emission proportional to the concentration ranging from 1.50 x 10(-8) to 7.50 x 10(-7)molL(-1) for Hg(2+) ion, 3.0 x 10(-7) to 1.0 x 10(-5)molL(-1) for Ni(2+) ion, 4.59 x 10(-8) to 2.295 x 10(-6)molL(-1) for Cu(2+) ion, and 1.20 x 10(-7) to 6.0 x 10(-6)molL(-1) Co(2+) ion, respectively. Based on the distinct optical properties of CdS QDs system with the five HTM ions, and the relatively wide linear range and rapid response to HTM ions, CdS QDs can be developed as a potential identified luminescence probe for familiar HTM ions detection in aqueous solution.