1.Improving the position specificity of Themomyces lanuginosus lipase based on semi-rational design.
Yadi MA ; Cuiping YOU ; Guoqiang ZHANG ; Jianghua LI ; Guocheng DU
Chinese Journal of Biotechnology 2023;39(8):3481-3493
Diacylglycerol (DAG) is an intermediate product in lipid metabolism and plays an important physiological role in human body. It is mainly prepared by hydrolyzing lipid with lipase. However, research on the detection method of 1, 2-diacylglycerol (1, 2-DAG) and 1, 3-diacylglycerol (1, 3-DAG) and catalytic specificity of lipase was not enough, which limits its wide application. To address these challenges, an efficient quantitative detection method was first established for 1, 2-DAG (0.025-0.200 g/L) and 1, 3-DAG (0.025-0.150 g/L) by combining supercritical fluid chromatography with evaporative light scattering detector and optimizing the detection and analysis parameters. Based on the molecular docking between Thermomyces lanuginosus lipase (TLL) and triolein, five potential substrate binding sites were selected for site-specific saturation mutation to construct a mutation library for enzyme activity and position specificity screening. The specificity of sn-1, 3 of the I202V mutant was the highest in the library, which was 11.7% higher than the specificity of the wild type TLL. In summary, the position specificity of TLL was modified based on a semi-rational design, and an efficient separation and detection method of DAG isomers was also established, which provided a reference for the study of the catalytic specificity of lipase.
Humans
;
Diglycerides
;
Molecular Docking Simulation
;
Binding Sites
;
Catalysis
;
Lipase/genetics*
2.Identification and 3D architecture analysis of the LIPC gene mutation in a pedigree with familial hypercholesterolemia-like phenotype.
Hang ZHANG ; Fang Yuan LI ; Yu HAO ; Xu Min WANG ; Ju ZHANG ; Ya Luan MA ; Hui ZENG ; Jie LIN
Chinese Journal of Cardiology 2023;51(7):716-721
Objective: To identify and analyze 3D architecture of the mutational sites of susceptible genes in a pedigree with familial hypercholesterolemia-like phenotype (FHLP). Methods: This is a case series study. A pedigree with suspected familial hypercholesterolemia was surveyed. The proband admitted in Beijing Anzhen Hospital in April 2019. Whole-exome sequencing was performed to determine the mutational sites of susceptible genes in the proband. Polymerase chain reaction (PCR) sequencing was used to verify the pathogenic variant on proband's relatives. The structural and functional changes of the proteins were analyzed and predicted by Discovery Studio 4.0 and PyMol 2.0. Results: The patients in the pedigree showed abnormal lipid profiles, especially elevated levels of total cholesterol(TC). The genetic screening detected the c.1330C>T SNP in the exon 8 of lipase C (LIPC) gene, this mutation leads to an amino acid substitution from arginine to cysteine at position 444 (Arg444Cys), in the proband and proband's father and brother. In this family, members with this mutation exhibited elevated TC, whereas lipid profile was normal from the proband's mother without this mutation. This finding indicated that LIPC: c.1330C>T mutation might be the mutational sites of susceptible genes. The analysis showed that Arg444Cys predominantly affected the ligand-binding property of the protein, but had a limited impact on catalytic function. Conclusion: LIPC: c.1330C>T is a new mutational site of susceptible genes in this FHLP pedigree.
Humans
;
Male
;
Hyperlipoproteinemia Type II/genetics*
;
Lipase/genetics*
;
Lipids
;
Mutation
;
Pedigree
;
Phenotype
;
Proteins
3.A case of neonatal-onset type I hyperlipoproteinemia with bloody ascites.
Yuan-Yuan CHEN ; Li-Yuan HU ; Ke ZHANG ; Xue-Ping ZHANG ; Yun CAO ; Lin YANG ; Bing-Bing WU ; Wen-Hao ZHOU ; Jin WANG
Chinese Journal of Contemporary Pediatrics 2023;25(12):1293-1298
This report presents a case of a male infant, aged 32 days, who was admitted to the hospital due to 2 days of bloody stools and 1 day of fever. Upon admission, venous blood samples were collected, which appeared pink. Blood biochemistry tests revealed elevated levels of triglycerides and total cholesterol. The familial whole genome sequencing revealed a compound heterozygous variation in the LPL gene, with one variation inherited from the father and the other from the mother. The patient was diagnosed with lipoprotein lipase deficiency-related hyperlipoproteinemia. Acute symptoms including bloody stools, fever, and bloody ascites led to the consideration of acute pancreatitis, and the treatment involved fasting, plasma exchange, and whole blood exchange. Following the definitive diagnosis based on the genetic results, the patient was given a low-fat diet and received treatment with fat-soluble vitamins and trace elements, as well as adjustments to the feeding plan. After a 4-week hospitalization, the patient's condition improved and he was discharged. Follow-up showed a decrease in triglycerides and total cholesterol levels. At the age of 1 year, the patient's growth and psychomotor development were normal. This article emphasizes the multidisciplinary diagnosis and treatment of familial hyperlipoproteinemia presenting with symptoms suggestive of acute pancreatitis, including bloody ascites, in the neonatal period.
Humans
;
Infant
;
Male
;
Acute Disease
;
Ascites
;
Cholesterol
;
Hyperlipoproteinemia Type I/genetics*
;
Hyperlipoproteinemias
;
Lipoprotein Lipase/genetics*
;
Pancreatitis
;
Triglycerides
4.Novel Pathogenic Mutation of PNPLA1 Identified in Autosomal Recessive Congenital Ichthyosis: A Case Report.
Li HAN ; Qian LIJUAN ; Xu NAN ; Huang LI ; Qiao LI-XING
Chinese Medical Sciences Journal 2022;37(4):349-352
Autosomal recessive congenital ichthyosis (ARCI) is characterized by being born as collodion babies, hyperkeratosis, and skin scaling. We described a collodion baby at birth with mild ectropion, eclabium, and syndactyly. Whole exome sequencing showed a compound heterozygous variant c.[56C>A], p.(Ser19X) and c.[100G>A], p.(Ala34Thr) in the PNPLA1 gene [NM_001145717; exon 1]. The protein encoded by PNPLA1 acts as a unique transacylase that specifically transfers linoleic acid from triglyceride to ω-hydroxy fatty acid in ceramide, thus giving rise to ω-O-acylceramide, a particular class of sphingolipids that is essential for skin barrier function. The variant was located in the patatin core domain of PNPLA1 and resulted in a truncated protein which could disrupt the function of the protein. This case report highlights a novel compound heterozygous mutation in PNPLA1 identified in a Chinese child.
Humans
;
Infant, Newborn
;
Acyltransferases/genetics*
;
Ceramides/metabolism*
;
Collodion
;
Ichthyosis, Lamellar/genetics*
;
Lipase/metabolism*
;
Mutation
;
Phospholipases/genetics*
6.CRISPR/Cas9 knockout plin1 enhances lipolysis in 3T3-L1 adipocytes.
Chenyi FENG ; Xiang XU ; Weipeng DONG ; Zhaoyang CHEN ; Jiong YAN
Chinese Journal of Biotechnology 2020;36(7):1386-1394
We used CRISPR/Cas9 to delete plin1 of 3T3-L1 preadipocyte, to observe its effect on lipolysis in adipocytes and to explore regulatory pathways. We cultured 3T3-L1 preadipocytes, and the plin1 knockout vectors were transfected by electroporation. Puromycin culture was used to screen successfully transfected adipocytes, and survival rates were observed after transfection. The optimized "cocktail" method was used to differentiate 3T3-L1 preadipocytes. The glycerol and triglyceride contents were determined by enzymatic methods. The changes in lipid droplet form and size were observed by Oil red O staining. The protein expression of PLIN1, PPARγ, Fsp27, and lipases was measured by Western blotting. RT-PCR was used to measure the expression of PLIN1 and lipases mRNA. After the adipocytes in the control group were induced to differentiate, the quantity of tiny lipid droplets was decreased, and the quantity of unilocular lipid droplets was increased and arranged in a circle around the nucleus. Compared with the control group, the volume of unilocular lipid droplets decreased, and the quantity of tiny lipid droplets increased after induction of adipocytes in the knockout group. The expression of PLIN1 mRNA and protein in the adipocytes was significantly inhibited (P<0.05); glycerol levels increased significantly (0.098 4±0.007 6), TG levels decreased significantly (0.031 0±0.005 3); mRNA and protein expression of HSL and ATGL increased (P<0.05); PPARγ and Fsp27 expression unchanged in adipocytes. The above results indicate that the knockout of plin1 enhances the lipolysis of 3T3-L1 adipocytes by exposing lipids in lipid droplets and up-regulating lipases effects.
3T3-L1 Cells
;
Adipocytes
;
metabolism
;
Animals
;
CRISPR-Cas Systems
;
Gene Knockout Techniques
;
Lipase
;
metabolism
;
Lipolysis
;
genetics
;
Mice
;
Perilipin-1
;
genetics
;
metabolism
7.Polymorphism analysis of virulence-related genes among Candida tropicalis isolates.
Li-Juan ZHANG ; Shuan-Bao YU ; Wen-Ge LI ; Wen-Zhu ZHANG ; Yuan WU ; Jin-Xing LU
Chinese Medical Journal 2019;132(4):446-453
BACKGROUND:
Adhesion, biofilm formation, yeast-hyphal transition, secretion of enzymes, and hemolytic activity are all considered important factors in Candida tropicalis infection. However, DNA sequence data for this pathogen are limited. In this study, the polymorphism and heterogeneity of genes agglutinin-like sequences (ALS)2, Lipase (LIP)1, LIP4, and secretory aspartyl proteinase tropicalis (SAPT)1-4 as well as the relationship between phenotype and genotype were analyzed.
METHODS:
This study started in August 2013, and ended in July 2017. The complete length of ALS2, LIP1, LIP4, and SAPT1-4 of 68 clinical C. tropicalis isolates was sequenced. Single nucleotide polymorphisms (SNPs) as well as insertions and deletions (indels) were identified within these genes. In addition, phenotypic characteristics of the virulent factors, including adhesion and the secretion of aspartyl proteinases and phospholipases, were determined.
RESULTS:
There were 73, 24, 17, 16, 13, and 180 SNPs in the genes LIP1, LIP4, SAPT1, SAPT2, SAPT3, and SAPT4, respectively. Furthermore, 209 SNPs were identified in total for the gene ALS2. Interestingly, large fragment deletions and insertions were also found in ALS2. Isolate FXCT 01 obtained from blood had deletions on all 4 sites and showed the lowest adhesion ability on the polymethylpentene surface. In addition, isolates with deletions in the regions 1697 to 1925 and 2073 to 2272 bp displayed relatively low abilities for adhesion and biofilm formation, and this phenotype correlated with the deletions found in ALS2. LIP1, SAPT4, and ALS2 displayed great heterogeneity among the isolates. Large deletions found in gene ALS2 appeared to be associated with the low ability of adhesion and biofilm formation of C. tropicalis.
CONCLUSION
This study might be useful for deeper explorations of gene function and studying the virulent mechanisms of C. tropicalis.
Bacterial Adhesion
;
Biofilms
;
Candida tropicalis
;
genetics
;
pathogenicity
;
Lipase
;
genetics
;
Polymorphism, Single Nucleotide
;
Virulence
;
genetics
8.Spoilage potential of psychrotrophic bacteria isolated from raw milk and the thermo-stability of their enzymes.
Lei YUAN ; Faizan A SADIQ ; Tong-Jie LIU ; Yang LI ; Jing-Si GU ; Huan-Yi YANG ; Guo-Qing HE
Journal of Zhejiang University. Science. B 2018;19(8):630-642
The storage and transportation of raw milk at low temperatures promote the growth of psychrotrophic bacteria and the production of thermo-stable enzymes, which pose great threats to the quality and shelf-life of dairy products. Though many studies have been carried out on the spoilage potential of psychrotrophic bacteria and the thermo-stabilities of the enzymes they produce, further detailed studies are needed to devise an effective strategy to avoid dairy spoilage. The purpose of this study was to explore the spoilage potential of psychrotrophic bacteria from Chinese raw milk samples at both room temperature (28 °C) and refrigerated temperature (7 °C). Species of Yersinia, Pseudomonas, Serratia, and Chryseobacterium showed high proteolytic activity. The highest proteolytic activity was shown by Yersinia intermedia followed by Pseudomonas fluorescens (d). Lipolytic activity was high in isolates of Acinetobacter, and the highest in Acinetobacter guillouiae. Certain isolates showed positive β-galactosidase and phospholipase activity. Strains belonging to the same species sometimes showed markedly different phenotypic characteristics. Proteases and lipases produced by psychrotrophic bacteria retained activity after heat treatment at 70, 80, or 90 °C, and proteases appeared to be more heat-stable than lipases. For these reasons, thermo-stable spoilage enzymes produced by a high number of psychrotrophic bacterial isolates from raw milk are of major concern to the dairy industry. The results of this study provide valuable data about the spoilage potential of bacterial strains in raw milk and the thermal resistance of the enzymes they produce.
Animals
;
Bacteria/genetics*
;
Bacterial Proteins/chemistry*
;
Biofilms
;
Cold Temperature
;
Dairy Products
;
Endopeptidases/chemistry*
;
Enzyme Stability
;
Food Microbiology
;
Hot Temperature
;
Lipase/chemistry*
;
Milk/microbiology*
;
Peptide Hydrolases/chemistry*
;
Phospholipases/chemistry*
;
RNA, Ribosomal, 16S/genetics*
;
Raw Foods/microbiology*
;
beta-Galactosidase/chemistry*
9.Effects of PNPLA3, TM6SF2 gene polymorphisms and its interactions with smoking and alcohol drinking on hepatitis B virus-associated hepatocellular carcinoma.
L Q WANG ; W H GUO ; Z W GUO ; P QIN ; R ZHANG ; X M ZHU ; D W LIU
Chinese Journal of Epidemiology 2018;39(12):1611-1616
Objective: To explore the SNP effects of patatin-like phospholipase domain which containing 3 (PNPLA3), transmembrane 6 superfamily member 2 (TM6SF2) gene, environmental effects of smoking, alcohol drinking and interaction between gene-gene, gene-environment and drinking-smoking on hepatitis B virus-associated hepatocellular carcinoma (HBV-HCC). Methods: We collected anticoagulant peripheral blood from patients of HBV-HCC, chronic hepatitis B (CHB), liver cirrhosis (LC) and from healthy controls to detect the single nucleotide polymorphism (SNP) of patatin-like phospholipase domain containing 3 (PNPLA3) gene loci rs738409 and transmembrane 6 superfamily member 2 (TM6SF2) gene loci rs58542926, using the flight mass spectrometry method. The optimal assignment value of gene polymorphisms was defined by using the online SNP stats. Hardy-Weinberg (H-W) balance was tested for SNP. Effects of the genetic and environmental factors to HBV-HCC were analyzed by using the multiple classification logistic regression method. The gene-gene, gene-smoking and alcohol drinking interaction effects were investigated by Fork-Life analysis and binary logistic regression methods. Results: The frequency distribution of CHB group rs738409 loci seemed not in conformity with the H-W balance (χ(2)=11.980, P<0.005). Two loci frequency distributions in the other groups were all in accordandce with the H-W balance. After adjusting for influences on age and sex and comparing to the healthy group, the rs58542926 mutation appeared as OR=1.659, 95%CI: 1.026-2.684, P=0.039, in the HBV-HCC group. When comparing to CHB group, the HBV-HCC group presented that drinking as OR=1.680, 95%CI: 1.121-2.519, P=0.012. When comparing to the LC group, the ORs of drinking and smoking were 1.539 (1.071-2.213) and 1.453 (1.005-2.099) respectively, in the HBV-HCC group. When comparing to the CHB+LC group, interactions between the HBV-HCC group were found rs738409 and rs58542926 on additive model OR=1.548 (U=1.885, P=0.029) and OR=1.658 (P=0.024) on logistic regression model while drinking was rs738409 on interaction additive model with OR=1.811(U=1.965, P=0.024). As for drinking and mutation of rs738409, the multiplication model of logistic regression showed no statistically significant differences. Interaction between smoking and drinking appeared as OR=1.756 (P<0.001) in the logistics regression multiplication model. Conclusions: Factors as mutation of TM6SF2, smoking and drinking all appeared as risk factors for HBV-HCC. Mutations of both PNPLA3 and TM6SF2, together with smoking and drinking all served as risk factors for HBV-HCC. However, the mutation of single PNPLA3 appeared as a protective factor on HBV-HCC.
Alcohol Drinking/adverse effects*
;
Carcinoma, Hepatocellular/virology*
;
Case-Control Studies
;
Epistasis, Genetic
;
Gene-Environment Interaction
;
Genetic Predisposition to Disease
;
Genotype
;
Hepatitis B virus
;
Hepatitis B, Chronic
;
Humans
;
Lipase/genetics*
;
Liver Cirrhosis, Alcoholic/complications*
;
Liver Neoplasms/virology*
;
Membrane Proteins/genetics*
;
Polymorphism, Single Nucleotide
;
Smoking/adverse effects*
10.Effect of Perinatal Bisphenol A Exposure on Serum Lipids and Lipid Enzymes in Offspring Rats of Different Sex.
Liang GAO ; Han Ning WANG ; Ling ZHANG ; Fang Yuan PENG ; Yue JIA ; Wei WEI ; Li Hong JIA
Biomedical and Environmental Sciences 2016;29(9):686-689
Rats were exposed to 1 or 10 μg/mL bisphenol A (BPA) in water during pregnancy and lactation. Offspring rats were given normal water and a standard diet from weaning to postnatal day (PND) 50. Perinatal exposure to BPA resulted in significantly increased body weight, visceral adipose tissue, abnormal serum lipids, and lower adiponectin (ADP) levels in both female and male offspring rats. Liver adipose triglyceride lipase (Atgl) mRNA levels and ADP protein in visceral adipose tissue were significantly decreased in BPA-exposed offspring rats. In both female or male offspring rats, obesity and dyslipidemia induced by perinatal exposure to BPA were associated with down regulation of Atgl mRNA in liver and ADP protein in visceral adipose tissue.
Adiponectin
;
metabolism
;
Adipose Tissue
;
metabolism
;
Animals
;
Benzhydryl Compounds
;
adverse effects
;
metabolism
;
Body Weight
;
Dyslipidemias
;
enzymology
;
etiology
;
metabolism
;
physiopathology
;
Female
;
Humans
;
Lipase
;
genetics
;
metabolism
;
Lipids
;
blood
;
Male
;
Obesity
;
enzymology
;
etiology
;
metabolism
;
physiopathology
;
Phenols
;
adverse effects
;
metabolism
;
Pregnancy
;
Prenatal Exposure Delayed Effects
;
enzymology
;
etiology
;
metabolism
;
physiopathology
;
Rats
;
Rats, Sprague-Dawley

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