Chemical modification for improving catalytic performance of lipase B from Candida antarctica with hydrophobic proline ionic liquid.

In this study, a series of proline ionic liquids with different lengths of hydrophobic alkyl on the side chain were used to modify the Candida Antarctic lipase B (CALB). The catalytic activity, thermal stability and tolerance to methanol and DMSO of the modified enzyme were all improved simultaneously. The optimum temperature changed from 55 to 60 â„ƒ. The hydrophobicity and anion type of the modifier have important influence on the catalytic performance of CALB. CALB modified by [ProC12][H2PO4] has a better effect. Under the optimal conditions, its hydrolysis activity was 3.0 times than that of the native enzyme, the catalytic efficiency Kcat/Km improved 2.8 times in aqueous phase, and the tolerance to organic solvent with strong polarity (50% methanol 2 h) was increased by 6.8 times. Fluorescence spectra and circular dichroism (CD) spectroscopy showed that the introduction of ionic liquids changed the microenvironment near the fluorophores of the enzyme protein, the α-helix decreased and ß-sheet increased in the secondary structure of the modified enzymes. The root mean square deviation (RMSD), residue root mean square fluctuation (RMSF), radius of gyration (Rg), and solution accessible surface area (SASA) of [ProC2][Br]-CALB, [ProC12][Br]-CALB and native CALB were obtained for comparison by molecular dynamics simulation. The results of dynamics simulation were in good agreement with enzymology experiment. The introduction of ionic liquids can keep CALB in a better active conformation, and proline ionic liquids with long hydrophobic chains can significantly improve the surface hydrophobicity and overall rigidity of CALB. This research offers a new idea for rapid screening of efficient modifiers and provision of enzymes with high stability and activity for industrial application.

Cholesteryl ester transfer protein TaqIB polymorphism and its association with serum lipid levels and longevity in Chinese Bama Zhuang population.

BACKGROUND: TaqIB polymorphism in the cholesteryl ester transfer protein (CETP) gene has been reported to be associated with serum high-density lipoprotein cholesterol (HDL-C) levels and longevity in several populations, but controversial results also arose probably due to racial/ethnic diversity. Bama is a remote and mountainous county located in the northwest of Guangxi, People's Republic of China, which has been well known for its longevity for centuries. The current study was to investigate the possible association of CETP TaqIB polymorphism with serum lipid levels and longevity in the Bama Zhuang population. METHODS: The CETP TaqIB genotypes were determined by polymerase chain reaction and restriction fragment length polymorphism in 523 long-lived inhabitants (long-lived group, LG; aged 90-107 years) and 498 healthy controls without longevity family history (non-long-lived group, non-LG; aged 40-69 years) residing in Bama County. RESULTS: The levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were higher but TG, HDL-C/LDL-C ratio and the prevalence of dyslipidemia were lower in LG than in non-LG (P < 0.001 for all). There were no differences in the allelic and genotypic frequencies between the two groups (P > 0.05). Serum HDL-C levels and HDL-C/LDL-C ratio in LG were different among the genotypes (P < 0.01 for each), the subjects with B2B2 and B1B2 genotyes had higher HDL-C levels and HDL-C/LDL-C ratio than the subjects with B1B1genotye, whereas the levels of TC and HDL-C in non-LG were different among/between the genotypes (P < 0.01 for each), the B2 allele carriers had lower TC and higher HDL-C levels than the B2 allele noncarriers. Serum TG and HDL-C levels and HDL-C/LDL-C ratio were correlated with genotypes in LG, whereas serum TC and HDL-C levels were associated with genotypes in non-LG (P < 0.05-0.001). CONCLUSIONS: The association of CETP TaqIB polymorphism and serum lipid profiles is different between LG and non-LG in the Chinese Bama Zhuang population. CETP TaqIB polymorphism might be one of the longevity-related genetic factors in this population.

Microsomal triglyceride transfer protein gene -493G/T polymorphism and its association with serum lipid levels in Bama Zhuang long-living families in China.

BACKGROUND: The -493G/T polymorphism in the microsomal triglyceride transfer protein (MTP) gene is associated with lower serum low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG) levels and longevity in several populations, but the results are inconsistent in different racial/ethnic groups. The current study was to investigate the plausible association of MTP -493G/T polymorphism with serum lipid levels and longevity in Zhuang long-lived families residing in Bama area, a famous home of longevity in Guangxi, China. METHODS: The MTP -493G/T was genotyped by PCR-restriction fragment length polymorphism in 391 Bama Zhuang long-lived families (BLF, n = 1467, age 56.60 ± 29.43 years) and four control groups recruited from Bama and out-of-Bama area with or without a familial history of exceptional longevity: Bama non-long-lived families (BNLF, n = 586, age 44.81 ± 26.83 years), Bama non-Zhuang long-lived families (BNZLF, n = 444, age 52.09 ± 31.91 years), Pingguo long-lived families (PLF, n = 658, age 50.83 ± 30.30 years), and Pingguo non-long-lived families (PNLF, n = 539, age 38.74 ± 24.69 years). Correlation analyses between genotypes and serum lipid levels and longevity were then performed. RESULTS: No particularly favorable lipoprotein and clinical phenotypes were seen in BLF as compared to general families in the same area. Instead, the levels of total cholesterol (TC), TG, LDL-C, and the prevalence of dyslipidemia were significantly higher in the three Bama families as compared to the two non-Bama families (P < 0.01 for all). There were no differences in the allelic and genotypic frequencies among the tested cohorts (P > 0.05 for all), but the TT genotype tended to enrich in the three long-lived cohorts from both areas. In addition, the individuals harboring TT genotype exhibited lower LDL-C and TC levels in the overall populations and Bama populations with a region- and sex-specific pattern. Multiple linear regression analyses unraveled that LDL-C levels were correlated with genotypes in Bama combined population, BNLF, and the total population (P < 0.05 for each) but not in Pingguo populations; TC and HDL-C levels were correlated with genotypes in Bama combined population and BLF, respectively (P < 0.05 for each). CONCLUSIONS: MTP -493G/T polymorphism may play an important role in fashioning the serum lipid profiles of Bama populations, despite no direct association between MTP -493G/T and longevity was detected.

Enhancing the Catalytic Performance of Candida antarctica Lipase B by Chemical Modification With Alkylated Betaine Ionic Liquids.

Various betaine ionic liquids composed of different chain lengths and different anions were designed and synthesized to modify Candida antarctica lipase B (CALB). The results showed that the catalytic activity of all modified lipases improved under different temperature and pH conditions, while also exhibiting enhanced thermostability and tolerance to organic solvents. With an increase in ionic liquid chain length, the modification effect was greater. Overall, CALB modified by [BetaineC16][H2PO4] performed best, with the modified CALB enzyme activity increased 3-fold, thermal stability increased 1.5-fold when stored at 70°C for 30 min, with tolerance increased 2.9-fold in 50% DMSO and 2.3-fold in 30% mercaptoethanol. Fluorescence and circular dichroism (CD) spectroscopic analysis showed that the introduction of an ionic liquid caused changes in the microenvironment surrounding some fluorescent groups and the secondary structure of the CALB enzyme protein. In order to establish the enzyme activity and stability change mechanisms of the modified CALB, the structures of CALB modified with [BetaineC4][Cl] and [BetaineC16][Cl] were constructed, while the reaction mechanisms were studied by molecular dynamics simulations. Results showed that the root mean square deviation (RMSD) and total energy of modified CALB were less than those of native CALB, indicating that modified CALB has a more stable structure. Root mean square fluctuation (RMSF) calculations showed that the rigidity of modified CALB was enhanced. Solvent accessibility area (SASA) calculations exhibited that both the hydrophilicity and hydrophobicity of the modified enzyme-proteins were improved. The increase in radial distribution function (RDF) of water molecules confirmed that the number of water molecules around the active sites also increased. Therefore, modified CALB has enhanced structural stability and higher hydrolytic activity.

Detection of nuclear matrix protein 22 and survivin baseline level in patients after radical cystectomy.

We investigated the baseline levels of urine nuclear matrix protein 22 (U-NMP22) and survivin in urine after radical cystectomy for primary invasive bladder cancer. We measured U-NMP22 and survivin values in 72 patients with four types of urinary diversion (Indiana bladder, Bricker bladder, Mainz bladder and orthotopic bladder) after radical cystectomy and 25 healthy volunteers. We also analyzed the relation between the U-NMP22 and survivin level and other variables among patients with continent urinary diversion and incontinent urinary diversion as well as healthy controls, and found that the U-NMP22 and survivin values were not associated with postoperative interval or gender. The U-NMP22 values (mean ± standard error) for continent urinary diversion, incontinent urinary diversion and healthy controls were 12.08 ± 0.10, 16.62 ± 0.15 and 0.01 ± 0.00 U/ml, respectively. The survivin values (mean ± standard error) for continent urinary diversion, incontinent urinary diversion and healthy controls were 0.47 ± 0.06, 0.69 ± 0.16 and 0.02 ± 0.03 U/ml, respectively. The U-NMP22 and survivin values in the Bricker bladder group were significantly higher than the values in the other three groups. We noted that increased levels of U-NMP22 and survivin after radical cystectomy varied according to different predictors, which may be useful for designing strategies to follow these cases.

[Progress in the research of genes related to human longevity].

Human longevity is the result of combined actions by many factors including genetics, environment and so on. Although longevity can take its natural course, it can be extended with social and scientific advances. This review presents the recent progress in longevity studies, especially on the research of longevity related genes in model species. It also summarizes the research of longevity related genes in humans in both the nuclear and mitochondrial genome. The prospect and strategy of human longevity research is also discussed.

Neither the tumor necrosis factor alpha-308 A/G polymorphism nor the alpha2-macroglobulin polymorphism was associated with late-onset Alzheimer's disease in the Chinese population.

Late-onset Alzheimer's disease (LOAD) is the most common cause of dementia in the elderly. It is a complex and genetically heterogeneous disorder. Epidemiological studies demonstrated that nonsteroidal anti-inflammatory drugs could prevent or delay the onset of LOAD suggesting inflammation may be involved in AD. Tumor necrosis factor (TNF) is a potent immunomodulator and it might increase the production of amyloid beta(Abeta), which makes it an appropriate AD candidate gene. Alpha2 macroglobulin (A2M) is a serum protease inhibitor and a major low-density lipoprotein receptor-related protein (LRP) ligand. It can bind Abeta and mediate its clearance and degradation, suggesting it might be another AD candidate gene. In the present study, we analyzed the a 5 bp Ins/Del polymorphism of A2M gene (A2M-2), TNF alpha-308 A/G polymorphism and apolipoprotein E (APOE) polymorphisms of 67 sporadic late-onset AD patients and 142 normal elderly controls in the Chinese population. Our data showed that the APOE epsilon4 allele frequency in AD was significantly higher than that in the normal controls (chi2 = 11.66, P < 0.01) neither the frequencies of genotypes nor alleles of the TNF alpha-308 A/G and A2M polymorphisms were significantly different between AD and controls,suggesting the two polymorphisms were not risk factors to LOAD in Chinese.

Photoselective green-light laser vaporisation vs. TURP for BPH: meta-analysis.

This study sought to evaluate the efficacy and safety of photoselective vaporisation (PVP) vs. transurethral resection of the prostate (TURP) for patients with benign prostatic hyperplasia (BPH). Eligible studies were identified from electronic databases (Cochrane Library, PubMed and EMBASE). The database search, quality assessment and data extraction were performed independently by two reviewers. Efficacy (primary outcomes: maximum urinary flow rate (Q(max)), international prostate symptom score (IPSS), postvoid residual urine (PVR) and quality of life (QoL); secondary outcomes: operative time, hospital time and catheter removal time) and safety (complications, such as transfusion and capsular perforation) were explored by using Review Manager 5.0. Six randomized controlled trials (RCTs) and five case-controlled studies of 1398 patients met the inclusion criteria. A meta-analysis of the extractable data showed that there were no differences in IPSS, Q(max), QoL or PVR between PVP and TURP (mean difference (MD): prostate sizes <70 ml, Q(max) at 24 months, MD=0.01, P=0.97; IPSS at 12 months, MD=0.18, P=0.64; QoL at 12 months, MD=-0.00, P=0.96; PVR at 12 months, MD=0.52, P=0.43; prostate sizes >70 ml, Q(max) at 6 months, MD=-3.46, P=0.33; IPSS at 6 months, MD=3.11, P=0.36; PVR at 6 months, MD=25.50, P=0.39). PVP was associated with a shorter hospital time and catheter removal time than TURP, whereas PVP resulted in a longer operative time than TURP. For prostate sizes <70 ml, there were fewer transfusions, capsular perforations, incidences of TUR syndrome and clot retentions following PVP compared with TURP. These results indicate that PVP is as effective and safe as TURP for BPH at the mid-term patient follow-up, in particular for prostate sizes <70 ml. Due to the different energy settings available for green-light laser sources and the higher efficiency and performance of higher-quality lasers, large-sample, long-term RCTs are required to verify whether different energy settings affect outcomes.

[Study on the risk of age-related diabetes mellitus among 8280 cases with metabolic syndrome patients and normal persons in Beijing.].

OBJECTIVE: To investigate the impact of age on patients with metabolic syndrome (MS) and normal persons. METHODS: Data was gathered from 8280 persons including 4873 males and 3407 females who were randomly selected. All subjects were divided into normal group and MS group. According to the interval of ten years, the subjects were divided into seven age groups, to calculate the difference of impaired fasting glycaemia (IFG) between patients with diabetes mellitus (DM) and normal people, as well as the related portions. RESULTS: (1) The risk of IFG and DM appeared to be different among age groups among the target subjects as well as in the normal and the MS groups (P < 0.05). (2) Among the whole subjects, the overall prevalence of IFG was increasing with age. The prevalence of DM had an increasing trend with age augment in 20 - 79 years group, whereas a decreasing trend appeared in people over 80 years of age. (3) For normal persons, the prevalence of IFG and DM were all increasing with age augment in 20 - 79 years group, and then decreasing with age augment in the over-80-years group. (4) For MS patients, the prevalence of IFG had an increasing trend with age augment in 20 - 69 years group, whereas a decreasing trend appeared in people over 70 years of age. There was no tendency of variation with age augment in DM. CONCLUSIONS: (1) For normal persons, high prevalence rates of IFG and DM were correlated to age augment, especially in senior persons. (2) For MS patients, high prevalence of IFG was also correlated to age augment, but no association between prevalence of DM and age augment was seen. (3) Age from 70 to 79 years appeared to be in high risk with MS.