2.Improving the thermal stability of Proteus mirabilis lipase based on multiple computational design strategies.
Bifei ZHANG ; Cheng LÜ ; Meng ZHANG ; Fei XU
Chinese Journal of Biotechnology 2022;38(4):1537-1553
Proteus mirabilis lipase (PML) features tolerance to organic solvents and great potential for biodiesel synthesis. However, the thermal stability of the enzyme needs to be improved before it can be used industrially. Various computational design strategies are emerging methods for the modification of enzyme thermal stability. In this paper, the complementary algorithm-based ABACUS, PROSS, and FoldX were employed for positive selection of PML mutations, and their pairwise intersections were further subjected to negative selection by PSSM and GREMLIN to narrow the mutation library. Thereby, 18 potential single-point mutants were screened out. According to experimental verification, 7 mutants had melting temperature (Tm) improved, and the ΔTm of K208G and G206D was the highest, which was 3.75 ℃ and 3.21 ℃, respectively. Five mutants with activity higher than the wild type (WT) were selected for combination by greedy accumulation. Finally, the Tm of the five-point combination mutant M10 increased by 10.63 ℃, and the relative activity was 140% that of the WT. K208G and G206D exhibited certain epistasis during the combination, which made a major contribution to the improvement of the thermal stability of M10. Molecular dynamics simulation indicated that new forces were generated at and around the mutation sites, and the rearrangement of forces near G206D/K208G might stabilize the Ca2+ binding site which played a key role in the stabilization of PML. This study provides an efficient and user-friendly computational design scheme for the thermal stability modification of natural enzymes and lays a foundation for the modification of PML and the expansion of its industrial applications.
Enzyme Stability
;
Lipase/chemistry*
;
Molecular Dynamics Simulation
;
Proteus mirabilis/metabolism*
;
Solvents/chemistry*
3.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*
4.Propeptide-mediated protein folding: mechanism and its impact on lipase.
Miao TIAN ; Jun ZHANG ; Wen LUO ; Zhiyuan WANG ; Junying FU ; Shaowei HUANG ; Pengmei LÜ
Chinese Journal of Biotechnology 2021;37(1):88-99
The formation of most proteins consists of two steps: the synthesis of precursor proteins and the synthesis of functional proteins. In these processes, propeptides play important roles in assisting protein folding or inhibiting its activity. As an important polypeptide chain coded by a gene sequence in lipase gene, propeptide usually functions as an intramolecular chaperone, assisting enzyme molecule folding. Meanwhile, some specific sites on propeptide such as glycosylated sites, have important effect on the activity, stability in extreme environment, methanol resistance and the substrate specificity of the lipase. Studying the mechanism of propeptide-mediated protein folding, as well as the influence of propeptide on lipases, will allow to regulate lipase by alternating the propeptide folding behavior and in turn pave new ways for protein engineering research.
Lipase/metabolism*
;
Molecular Chaperones/metabolism*
;
Protein Folding
;
Protein Precursors
;
Substrate Specificity
5.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
6.Screening, purification, and characterization of an extracellular lipase from Aureobasidium pullulans isolated from stuffed buns steamers.
Yang LI ; Tong-Jie LIU ; Min-Jie ZHAO ; Hui ZHANG ; Feng-Qin FENG
Journal of Zhejiang University. Science. B 2019;20(4):332-342
An extracellular lipase from Aureobasidium pullulans was obtained and purified with a specific activity of 17.7 U/mg of protein using ultrafiltration and a DEAE-Sepharose Fast Flow column. Characterization of the lipase indicated that it is a novel finding from the species A. pullulans. The molecular weight of the lipase was 39.5 kDa, determined by sodium dodecyl sulfonate-polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme exhibited its optimum activity at 40 °C and pH of 7. It also showed a remarkable stability in some organic solutions (30%, v/v) including n-propanol, isopropanol, dimethyl sulfoxide (DMSO), and hexane. The catalytic activity of the lipase was enhanced by Ca2+ and was slightly inhibited by Mn2+ and Zn2+ at a concentration of 10 mmol/L. The lipase was activated by the anionic surfactant SDS and the non-ionic surfactants Tween 20, Tween 80, and Triton X-100, but it was drastically inhibited by the cationic surfactant cetyl trimethyl ammonium bromide (CTAB). Furthermore, the lipase was able to hydrolyze a wide variety of edible oils, such as peanut oil, corn oil, sunflower seed oil, sesame oil, and olive oil. Our study indicated that the lipase we obtained is a potential biocatalyst for industrial use.
Ascomycota/enzymology*
;
Calcium
;
Catalysis
;
Corn Oil/metabolism*
;
Detergents/chemistry*
;
Enzyme Stability
;
Fungal Proteins/chemistry*
;
Glucans/chemistry*
;
Hexanes/chemistry*
;
Hydrogen-Ion Concentration
;
Hydrolysis
;
Industrial Microbiology
;
Lipase/chemistry*
;
Manganese/chemistry*
;
Olive Oil/metabolism*
;
Peanut Oil/metabolism*
;
Sesame Oil/metabolism*
;
Substrate Specificity
;
Sunflower Oil/metabolism*
;
Surface-Active Agents
;
Temperature
;
Zinc/chemistry*
7.Triglyceride-Rich Lipoproteins and Novel Targets for Anti-atherosclerotic Therapy
Korean Circulation Journal 2018;48(12):1097-1119
Although elevated serum low-density lipoprotein-cholesterol (LDL-C) is without any doubts accepted as an important risk factor for cardiovascular disease (CVD), the role of elevated triglycerides (TGs)-rich lipoproteins as an independent risk factor has until recently been quite controversial. Recent data strongly suggest that elevated TG-rich lipoproteins are an independent risk factor for CVD and that therapeutic targeting of them could possibly provide further benefit in reducing CVD morbidity, events and mortality, apart from LDL-C lowering. Today elevated TGs are treated with lifestyle interventions, and with fibrates which could be combined with omega-3 fatty acids. There are also some new drugs. Volanesorsen, is an antisense oligonucleotid that inhibits the production of the Apo C-III which is crucial in regulating TGs metabolism because it inhibits lipoprotein lipase (LPL) and hepatic lipase activity but also hepatic uptake of TGs-rich particles. Evinacumab is a monoclonal antibody against angiopoietin-like protein 3 (ANGPTL3) and it seems that it can substantially lower elevated TGs levels because ANGPTL3 also regulates TGs metabolism. Pemafibrate is a selective peroxisome proliferator-activated receptor alpha modulator which also decreases TGs, and improves other lipid parameters. It seems that it also has some other possible antiatherogenic effects. Alipogene tiparvovec is a nonreplicating adeno-associated viral vector that delivers copies of the LPL gene to muscle tissue which accelerates the clearance of TG-rich lipoproteins thus decreasing extremely high TGs levels. Pradigastat is a novel diacylglycerol acyltransferase 1 inhibitor which substantially reduces extremely high TGs levels and appears to be promising in treatment of the rare familial chylomicronemia syndrome.
Apolipoprotein C-III
;
Cardiovascular Diseases
;
Diacylglycerol O-Acyltransferase
;
Fatty Acids, Omega-3
;
Fibric Acids
;
Hyperlipoproteinemia Type I
;
Life Style
;
Lipase
;
Lipoprotein Lipase
;
Lipoproteins
;
Metabolism
;
Mortality
;
PPAR alpha
;
Risk Factors
;
Triglycerides
8.Blood Sugar Control and Low-Carbohydrate High-Fat Diet.
Journal of Korean Diabetes 2018;19(4):237-245
Diabetes patients and pre-diabetic patients are increasing worldwide. Type 2 diabetes starts with insulin resistance, and the long-term habit of stimulating insulin secretions causes insulin resistance and accumulates body fat to develop obesity and non-alcoholic fatty liver into diabetes. It also causes a variety of chronic diseases such as high blood pressure, polycystic ovary diseases, cancer and dementia. Insulin resistance is caused by an unbalanced lifestyle, and among other factors, the balance of the macronutrient is a very important factor. Koreans are characterized by high carbohydrate intake. Given the increasing prevalence of diabetes and the characteristics of Korean physical and eating habits, a more effective balance of diet education is needed. Therefore, it is very important for clinical dietitian to understand the carbohydrate and fat metabolism caused by insulin, and the concept of balanced diet for blood sugar control needs to be shifted from low-fat high-carbohydrate diet to low-carbohydrate high-fat diet.
Adipose Tissue
;
Blood Glucose*
;
Chronic Disease
;
Dementia
;
Diet
;
Diet, Fat-Restricted
;
Diet, High-Fat*
;
Eating
;
Education
;
Fatty Liver
;
Female
;
Humans
;
Hypertension
;
Insulin
;
Insulin Resistance
;
Life Style
;
Lipoprotein Lipase
;
Metabolism
;
Nutritionists
;
Obesity
;
Ovary
;
Prevalence
9.Pomegranate leaf attenuates lipid absorption in the small intestine in hyperlipidemic mice by inhibiting lipase activity.
Xuan YU ; Xin-Pei WANG ; Fan LEI ; Jing-Fei JIANG ; Jun LI ; Dong-Ming XING ; Li-Jun DU
Chinese Journal of Natural Medicines (English Ed.) 2017;15(10):732-739
Pomegranate leaf (PGL) has a definite role in regulating lipid metabolism. However, pharmacokinetic results show the main active ingredient, ellagic acid, in PGL has lower oral bioavailability, suggesting that the lipid-lowering effect of PGL may act through inhibiting lipid absorption in the small intestine. Our results demonstrated that pomegranate leaf and its main active ingredients (i.e., ellagic acid, gallic acid, pyrogallic acid and tannic acid) were capable of inhibiting pancreatic lipase activity in vitro. In computational molecular docking, the four ingredients had good affinity for pancreatic lipase. Acute lipid overload experiments showed that a large dosage of PGL significantly reduced serum total cholesterol (TG) and triglycerides (TC) levels in addition to inhibiting intestinal lipase activity, which demonstrated that PGL could inhibit lipase activity and reduce the absorption of lipids. We also found that PGL could reverse the reduced tight-junction protein expression due to intestinal lipid overload, promote Occludin and Claudin4 expression in the small intestine, and enhance the intestinal mucosal barrier. In conclusion, we demonstrated that PGL can inhibit lipid absorption and reduce blood TG and TC by targeting pancreatic lipase, promoting tight-junction protein expression and thereby preventing intestinal mucosa damage from an overload of lipids in the intestine.
Animals
;
Enzyme Inhibitors
;
administration & dosage
;
chemistry
;
Humans
;
Hyperlipidemias
;
drug therapy
;
enzymology
;
metabolism
;
Intestinal Absorption
;
Intestine, Small
;
metabolism
;
Kinetics
;
Lipase
;
chemistry
;
metabolism
;
Lipid Metabolism
;
Lythraceae
;
chemistry
;
Male
;
Mice
;
Mice, Inbred ICR
;
Plant Extracts
;
administration & dosage
;
chemistry
;
Plant Leaves
;
chemistry
;
Triglycerides
;
metabolism
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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