1.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
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Infant, Newborn
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Acyltransferases/genetics*
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Ceramides/metabolism*
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Collodion
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Ichthyosis, Lamellar/genetics*
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Lipase/metabolism*
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Mutation
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Phospholipases/genetics*
2.Study on the characteristics of tissue expression of hormone sensitive lipase and triacylglycerol hydrolase in pigs.
Qi WANG ; Li-Hong ZHANG ; Li-Jie ZHANG ; Gong-She YANG
Chinese Journal of Biotechnology 2007;23(5):831-835
The specific expression of TGH and HSL genes in different tissues of Bamei pig was investigated by RT-PCR and Western blot in this study. The result of RT-PCR showed that the expression of HSL could be detected in all these seven tissues examined, and which was higher expressed in fat, lower in heart, liver, lung, spleen and kidney. Expression of TGH gene could also be detected in seven tissues, and higher in liver and fat, lower in heart and kidney and lowest in spleen and lung. The result of Western blot showed that, HSL gene was highest expressed in epiploica fat and subcutaneous fat, higher in other tissues, but couldn' t be detected in kidney. Expression of TGH was detected in epiploica fat, subcutaneous fat, liver, lung and spleen, and highest in fat and liver, but it hadn't be found in heart and kidney. These results suggested that both HSL and TGH could be regulated by post-transcriptional, and their function was involved in different tissues.
Animals
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Gene Expression Regulation
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Lipase
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genetics
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metabolism
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Male
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Sterol Esterase
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genetics
;
metabolism
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Swine
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Tissue Distribution
3.Engineering the enantioselectivity of biocatalysts.
Chinese Journal of Biotechnology 2009;25(12):1770-1778
Wild-type biocatalysts usually show high activity and selectivity towards their native substrates. Since non-native substrates are often used in synthetically useful biocatalytic transformations, it is necessary to engineer enzymes for improved activity, stability and selectivity (chemo-, regio- and stereoselectivity). Herein we give an overview of the recent advances in engineering the enantioselectivity of biocatalysts, with an aim to stimulate further development of this important field in China.
Animals
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Biocatalysis
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Epoxide Hydrolases
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genetics
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metabolism
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Esterases
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genetics
;
metabolism
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Humans
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Lipase
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genetics
;
metabolism
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Protein Engineering
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methods
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Stereoisomerism
5.Characterization of a key gene in membrane lipid cycle in Synechocystis sp. PCC6803.
Qianqian GAO ; Xiaoming TAN ; Xuefeng LÜ
Chinese Journal of Biotechnology 2012;28(12):1473-1481
Free fatty acid profiles of wild type and fatty acyl-ACP synthase deletion mutant strain of Synechocystis sp. PCC6803 indicated that one origin of these fatty acids is the process of lipid remodeling or lipid degradation. Lipase is the key enzyme involved in this process. The gene sll1969 is the sole gene encodes a putative lipase in Synechocystis sp. PCC6803. To identify the function of this gene and its role in fatty acid metabolism, we cloned the sll1969 from genomic DNA, overexpressed it in Escherichia coli BL21 (DE3) using pET expression system and purified this recombinant enzyme with Nickel-nitrilotriacetic acid affinity chromatography. The enzyme activity was assayed by spectrophotometric with p-nitro-phenylbutyrate as substrate. The K(m) and k(cat) of the enzyme is (1.16 +/- 0.01) mmol/L and (332.8 +/- 10.0)/min, respectively toward p-nitro-phenylbutyrate at 30 degrees C. The optimal temperature of the enzyme is 55 degrees C. To investigate the biological role of Sll1969 in fatty acid metabolism in cyanobacteria, we constructed sll1969 deletion and overexpression mutant strains in the background of fatty acyl-ACP synthase deletion mutant of Synechocystis sp. PCC6803. The analyses of the content of free fatty acids in different mutant strains showed that the contents of Sll1969 and free fatty acid are positively correlated. The free fatty acid profiles of the sll1969 mutant strains suggested this enzyme is not the sole enzyme for degrading lipid in Synechocystis sp. PCC6803.
Escherichia coli
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genetics
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metabolism
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Fatty Acids, Nonesterified
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metabolism
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Lipase
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biosynthesis
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genetics
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Membrane Lipids
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genetics
;
metabolism
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Mutation
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Recombinant Proteins
;
biosynthesis
;
genetics
;
metabolism
;
Synechocystis
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enzymology
;
genetics
;
metabolism
6.Synthesis of flavor esters catalyzed by CALB-displaying Pichia pastoris whole-cells in non-aqueous phase.
Zi JIN ; Ying LIN ; Dengfeng HUANG ; Guodong SU ; Shuangyan HAN
Chinese Journal of Biotechnology 2009;25(12):1927-1932
An enzyme-displaying yeast as a whole-cell biocatalyst seemed an alternative to immobilized enzyme, due to its low-cost preparation and simple recycle course. Here, we tried to use a recombinant Pichia pastoris displaying Candida antarctica lipase B (CALB) to catalyze the synthesis of short chain flavor esters in n-heptane. We studied some major influential factors of esterification reactions, such as carbon chain length of the substrates, alcohol structure, enzyme concentration, substrates concentration, molar ratio of the substrates. The acid conversions were determined by titration and gas chromatography analysis. About ten kinds of esters were synthesized successfully, and the acid conversions of eight esters reached as high as 90% after reaction for 6 h. The result also indicated that ethanol and hexanoic acid were the most suitable substrates for this whole-cell catalyst. Under the optimal reaction conditions (the amount of lipase 20 g/L (306.0 U/g-dry cell), hexanoic acid concentration 0.8 mol/L, the molar ratio of hexanoic acid to ethanol 1:1.1), hexanoic acid conversion reached 97.3% after reaction for 1.5 h. To our knowledge, the CALB-displaying P. pastoris whole-cell biocatalyst showed good tolerance for high substrates concentration and exhibited high reaction rate on esterification of short chain flavor esters among the present enzyme/cell reported. Thus, CALB-displaying P pastoris whole-cell biocatalyst was promising in commercial application for flavor esters synthesis in non-aqueous phase.
Biocatalysis
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Candida
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enzymology
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Enzymes, Immobilized
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Esters
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metabolism
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Fungal Proteins
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Lipase
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biosynthesis
;
genetics
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Pichia
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genetics
;
metabolism
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Recombinant Proteins
;
biosynthesis
;
genetics
7.Overexpression of Penicillium expansum lipase gene in Pichia pastoris.
Cai YUAN ; Lin LIN ; Qiao-Qin SHI ; Song-Gang WU
Chinese Journal of Biotechnology 2003;19(2):231-235
The alkaline lipase gene of Penicillium expansum (PEL) was coloned into the yeast integrative plasmid pPIC3.5K, which was then transformed into His4 mutant yeast GS115. Recombinant Pichia strains were obtained by minimal olive oil-methanol plates screening and confirmed by PCR. The expression producus of PEL gene was analysis by SDS-PAGE and olive oil plate, the result indicated that PEL gene was functionally overexpressed in Pichia pastoris and up to 95% of the secreted protein. Recombinant lipase had a molecular mass of 28kD, showing a range similar to that of PEL, could hydrolyze olive oil and formed clear halos in the olive oil plates. Four different strategies (different media, pH, glycerol and methanol concentration) were applied to optimize the cultivation conditions, the activity of lipase was up to 260 u/mL under the optimal cultivation conditions. It is pointed out that the absence of the expensive biotin and yeast nitrogen base in the medium increased the lipase production. The possible reason of this result is absence of yeast nitrogen base increased the medium pH during cultivation, and PEL shows a higher stability at this condition. The lipase activity of the supernatant from the culture grown at pH 7 was higher than the one from the culture in the same medium at pH 6.0 is due to the pH stability of PEL too. The results also showed that the methanol and glycerol concentration had a marked effect on the production of lipase.
Enzyme Stability
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Fungal Proteins
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genetics
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metabolism
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Genetic Vectors
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genetics
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Hydrogen-Ion Concentration
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Lipase
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genetics
;
metabolism
;
Models, Genetic
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Penicillium
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enzymology
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genetics
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Pichia
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genetics
;
metabolism
;
Plasmids
;
genetics
8.Expression of Candida antarctica lipase B on yeast surface and synthesis of ethyl hexanoate catalyzed by CALB.
Zhiyou PAN ; Shuangyan HAN ; Ying LIN ; Suiping ZHENG
Chinese Journal of Biotechnology 2008;24(4):673-678
Short-chain esters play a significant role in the food industry as flavor and aroma constituents. Candida antarctica lipase B (CALB) is one of the most effective catalysts for organic synthesis. We constructed a CALB-displaying yeast whole-cell biocatalyst and applied it to esterification from caproic acid and ethanol. CALB was fused with the alpha-agglutinin C-terminal and the signal peptide of Glucoamylase in pICAS, a yeast surface display vector, to construct plasmid pICAS-CALB. An extremely Asn-rich linker, named celAL was inserted in the Xho I of pICAS-CALB to construct plasmid pICAS-celAL-CALB. The fused gene was under the control of GAPDH promoter. After incubated at 30 degrees C for 96 h the lipase hydrolytic activity of the yeast whole cells reached a plateau, 26.26 u/(g x dry cell). In nonaqeous media, the yield of 98.0% ethyl hexanoate was obtained after 24 h esterification from caproic acid and ethanol (the molar ratio of caproic acid : ethanol = 1 : 1.25) using lyophilized CALB displaying yeast whole cells.
Biocatalysis
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Candida
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enzymology
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Caproates
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metabolism
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Cloning, Molecular
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Fungal Proteins
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Genetic Engineering
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Lipase
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biosynthesis
;
genetics
;
Saccharomyces cerevisiae
;
genetics
;
metabolism
9.Screening and characterization of lipase from a metagenome library of dairy rumen microflora.
Shengguo ZHAO ; Jiaqi WANG ; Kailang LIU ; Yaxin ZHU ; Dengpan BU ; Dan LI ; Ping YU
Chinese Journal of Biotechnology 2009;25(6):869-874
Using lipase segregation agar containing trioleoylglycerol, we obtained 18 lipase positive clones by screening from a metagenome library of dairy rumen microflora containing 15,360 clones. The average insert size of lipase positive clones was about 60 kb. Lipase enzyme activity analysis by p-NPP method indicated that Lipase6, Lipase7 and Lipase8 had higher lipolytic activities to substrates of p-nitrophenyl palmitate (C16), p-nitrophenyl alaurate (C12) and p-nitrophenyl palmitate (C16) respectively. The optimum pH of Lipase 6, Lipase 7 and Lipase 8 were 7.5. The halflife period of Lipase 8 with the value of 15 min in 70 degrees C decreased with the increase of temperature. In conclusion, the lipases screened in this study had different substrates specificity and good thermo stability, which laid a basis for large-scale industrial application.
Animals
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Bacteria
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genetics
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Cattle
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Cloning, Molecular
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Female
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Gene Library
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Lipase
;
genetics
;
metabolism
;
Metagenome
;
genetics
;
Rumen
;
microbiology
;
Substrate Specificity
;
Temperature
10.Effects of leptin on porcine primary adiocytes lipolysis and mRNA expression of key lipolytic enzymes.
Yucheng LI ; Xueli ZHENG ; Gongshe YANG
Chinese Journal of Biotechnology 2008;24(9):1613-1619
Leptin, a cytokine predominantly secreted from fat tissue, plays an important role in regulating organism energy balance. Leptin can stimulate lipolysis, but the mechanism is unclear. In order to study the molecular mechanism of leptin stimulating lipolysis, we systemically studied the mRNA expression of key lipolytic enzymes. Morphological observation, Oil Red O staining and RT-PCR were used to identify pig primary adipocytes; commercial kits were used to measure the glycerol and FFA release; Semiquantitative RT-PCR was used to detect the mRNA expression of key lipolytic enzymes. The results showed that 100 nmol/L leptin up-regulated the mRNA expression of ATGL, TGH-2, HSL, MGL and LPL (P<0.01), but down-regulated the Perilipin mRNA expression (P<0.01). At the same time, leptin promoted the glycerol release in a dose dependent manner (P<0.01), but had no effect on the FFA release (P>0.05). These indicate that leptin may mainly stimulate lipolysis in pig primary adipocytes by up-regulating the expression of ATGL, MGL, LPL and down-regulating the expression of Perilipin. The unchanged FFA release may be resulted from Leptin promoting UCPs mRNA expression and increasing FFA expenditure.
Adipocytes
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cytology
;
enzymology
;
metabolism
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Animals
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Animals, Newborn
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Cells, Cultured
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Leptin
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pharmacology
;
Lipase
;
genetics
;
metabolism
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Lipolysis
;
drug effects
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Male
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Monoacylglycerol Lipases
;
genetics
;
metabolism
;
RNA, Messenger
;
genetics
;
metabolism
;
Swine