Characterization and Expression of a GDSL-Like Lipase Gene from Brassica napus in Nicotiana benthamiana

The GDSL esterase and lipase families play important roles in abiotic stress, pathogen defense, seed development and lipid metabolism. Identifying the lipase activity of the putative GDSL lipase is the prerequisite for dissecting its function. According to the sequence similarity and the conserved domains, we cloned the Brassica napus BnGLIP gene, which encodes a GDSL-like protein. We failed to identify the BnGLIP lipase activity in the bacterium and yeast expression systems. In this paper, we expressed the BnGLIP gene by fusing a 6× His tag in Nicotiana benthamiana and purified the recombinant protein. The extraction buffer contained 1 % (v/v) n-caprylic acid and was able to remove most of the protein impurities. About 50 μg of recombinant BnGLIP was obtained from 1 g of N. benthamiana leaves. The lipase activity was tested with the purified BnGLIP and the maximum enzyme activity reached 17.7 mM/mg. In conclusion, this study found that the recombinant protein BnGLIP expressed in tobacco system was effectively purified and was detected as a GDSL lipase.     

基因拷贝数和甲醇浓度对重组毕赤酵母产华根霉脂肪酶的影响

将华根霉脂肪酶基因克隆到甲基营养型毕赤酵母中表达,以甲醇利用快型菌株为宿主,在7 L发酵罐水平对脂肪酶基因拷贝数分别为3、5、6的3株基因重组菌——XY RCL-3、XY RCL-5、XY RCL-6进行高密度发酵调控,同时研究了甲醇浓度对表达华根霉脂肪酶的影响。结果表明,XY RCL-5在相同条件下发酵产酶能力高于XY RCL-6和XY RCL-3,最适甲醇诱导浓度控制在0.1%±0.02%时,酶活可达到12 500 U/mL,菌体干重达到204 g/L,蛋白浓度也能达到8.02 g/L。     

Cloning,expression and characterization of a lipase gene (<Emphasis Type="Italic">lip3</Emphasis>) from<Emphasis Type="Italic"> Pseudomonas aeruginosa</Emphasis> LST-03

A lipase gene (lip3) was cloned from the Pseudomonas aeruginosa strain LST-03 (which tolerates organic solvents) and expressed in Escherichia coli. The cloned sequence includes an ORF consisting of 945 nucleotides, encoding a protein of 315 amino acids (Lip3 lipase, 34.8 kDa). The predicted Lip3 lipase belongs to the class of serine hydrolases; the catalytic triad consists of the residues Ser-137, Asp-258, and His-286. The gene cloned in the present study does not encode the LST-03 lipase, a previously isolated solvent-stable lipase secreted by P. aeruginosa LST-03, because the N-terminal amino acid sequence of the Lip3 lipase differs from that of the LST-03 lipase. Although the effects of pH on the activity and stability of the Lip3 lipase, and the temperature optimum of the enzyme, were similar to those of the LST-03 lipase, the relative activity of the Lip3 lipase at lower temperatures (0–35°C) was higher than that of the LST-03 lipase. In the absence of organic solvents, the half-life of the Lip3 lipase was similar to that of the LST-03 lipase. However, in the presence of most of the organic solvents tested in this study (the exceptions were ethylene glycol and glycerol), the stability of the Lip3 lipase was lower than that of the LST-03 lipase.Communicated by H. Ikeda     

Gene Cloning and Characterization of a Novel Highly Organic Solvent Tolerant Lipase from Proteus sp. SW1 and its Application for Biodiesel Production

Proteus sp. SW1 was found to produce an extracellular solvent tolerant lipase. The gene, lipA, encoding a bacterial lipase, was cloned from total Proteus sp. SW1 DNA. lipA was predicted to encode a 287 amino acid protein of 31.2?kDa belonging to the Group I proteobacterial lipases. Purified His-tagged LipA exhibited optimal activity at pH 10.0 and 55??C. It was highly stable in organic solvents retaining 112% of its activity in 100% isopropanol after 24?h, and exhibited more than 200% of its initial activity upon exposure to 60% acetone, ethanol, and hexane for 18?h. Biodiesel synthesis reactions, using a single step addition of 13% an acyl acceptor ethanol, showed that LipA was highly effective at converting palm oil into biodiesel.     

Chaperone-dependent gene expression of organic solvent-tolerant lipase from Pseudomonas aeruginosa strain S5

The gene coding for the intracellular organic solvent-tolerant lipase of Pseudomonas aeruginosa strain S5 was isolated from a genomic DNA library and cloned into pRSET. The cloned sequence included two open reading frames (ORF) of 1575 bp for the first ORF (ORF1), and 582 bp for the second ORF (ORF2). The ORF2, known as chaperone, plays an important role in the expression of the S5 gene. The ORF2 is located downstream of lipase gene, and functions as the act gene for ORF1. The conserved pentapeptide, Gly-X-Ser-X-Gly, is located in the ORF1. A sequence coding for a catalytic triad that resembles that of a serine protease, consisting of serine, histidine, and aspartic acid or glutamic acid residues, was present in the lipase gene. Expression of the S5 lipase gene in E. coli resulted in a 100-fold increase in enzyme activity 9 h after induction with 0.75 mM IPTG. The recombinant protein revealed a size of 60 kDa on SDS-PAGE. The Lip S5 gene was stable in the presence of 25% (v/v) n-dodecane and n-tetradecane after 2 h incubation at 37 °C.     

Characterisation of a thermo-alkali-stable lipase from oil-contaminated soil using a metagenomic approach

Lipases are widely used for a variety of biotechnological applications. Screening these industrial enzymes directly from environmental microorganisms is a more efficient and practical approach than conventional cultivation-dependent methods. Combined with activity-based functional screening, six clones with lipase activity were detected and a gene (termed lipZ01) isolated from a target clone with the highest lipase activity was cloned from an oil-contaminated soil-derived metagenomic library and then sequenced. Gene lipZ01 was expressed in Pichia pastoris GS115 and the molecular weight of the recombinant lipase LipZ01 was estimated by electrophoresis analysis to be approximately 50 kDa. The maximum activity of the purified lipase was 42 U/mL, and the optimum reaction temperature and pH value were 45 °C and 8.0, respectively. The enzyme was highly stable in the temperature range 35–60 °C and under alkaline conditions (pH 7–10). The presence of Ca²⁺ and Mn²⁺ ions could significantly enhance the activity of the lipase. The purified lipase preferentially hydrolysed triacylglycerols with acyl chain lengths ≥8 carbon atoms, and the conversion degree of biodiesel production was nearly 92% in a transesterification reaction using olive oil and methanol. Some attractive properties suggested that the recombinant lipase may be valuable in industrial applications.     

Recombinant PNPLA3 protein shows triglyceride hydrolase activity and its I148M mutation results in loss of function

The patatin-like phospholipase domain containing 3 (PNPLA3, also called adiponutrin, ADPN) is a membrane-bound protein highly expressed in the liver. The genetic variant I148M (rs738409) was found to be associated with progression of chronic liver disease. We aimed to establish a protein purification protocol in a yeast system (Pichia pastoris) and to examine the human PNPLA3 enzymatic activity, substrate specificity and the I148M mutation effect. hPNPLA3 148I wild type and 148M mutant cDNA were cloned into P. pastoris expression vectors. Yeast cells were grown in 3 L fermentors. PNPLA3 protein was purified from membrane fractions by Ni-affinity chromatography. Enzymatic activity was assessed using radiolabeled substrates. Both 148I wild type and 148M mutant proteins are localized to the membrane. The wild type protein shows a predominant lipase activity with mild lysophosphatidic acid acyl transferase activity (LPAAT) and the I148M mutation results in a loss of function of both these activities. Our data show that PNPLA3 has a predominant lipase activity and I148M mutation results in a loss of function.     

Expression and Biochemical Characterization of a Thermophilic Organic Solvent-Tolerant Lipase from Bacillus sp. DR90

The objective of the present study was the isolation, molecular cloning and biochemical characterization of a thermophilic organic solvent-resistant lipase from Bacillus sp. DR90. The lipase gene was expressed in Escherichia coli BL21(DE3) using pET-28a(+) vector. The purification of recombinant lipase was conducted by nickel affinity chromatography and its biochemical properties were determined. The lipase sequence with an ORF of 639 bp contains the conserved pentapeptide Ala-His-Ser-Met-Gly. His-tagged recombinant lipase had a specific activity of 1,126 U/mg with a molecular mass of 26.8 kDa. The cloned lipase was optimally active at pH 8.0 and 75 °C representing high stability in broad ranges of temperature and pH. High performance liquid chromatography was used to determine the major compounds released during the lipase-catalyzed reaction of p-nitrophenyl derivatives as well as the substrate specificity. The purified lipase showed high compatibility towards various organic solvents, surfactants and commercial solid/liquid detergents; therefore the recombinant DR90 lipase could be considered as a probable candidate for future applications, predominantly in detergent processing industries.     

Cloning,Expression and Characterization of a Lipase Encoding Gene from Human Oral Metagenome

The human oral metagenomic DNA cloned into plasmid pUC19 was used to construct a DNA library in Escherichia coli. Functional screening of 40,000 metagenomic clones led to identification of a clone LIP2 that exhibited halo on tributyrin agar plate. Sequence analysis of LIP2 insert DNA revealed a 939 bp ORF (omlip1) which showed homology to lipase 1 of Acinetobacter junii SH205. The omlip1 ORF was cloned and expressed in E. coli BL21 (DE3) using pET expression system. The recombinant enzyme was purified to homogeneity and the biochemical properties were studied. The purified OMLip1 hydrolyzed p-nitrophenyl esters and triacylglycerol esters of medium and long chain fatty acids, indicating the enzyme is a true lipase. The purified protein exhibited a pH and temperature optima of 7 and 37 °C respectively. The lipase was found to be stable at pH range of 6–7 and at temperatures lower than 40 °C. Importantly, the enzyme activity was unaltered, by the presence or absence of many divalent cations. The metal ion insensitivity of OMLip1offers its potential use in industrial processes.     

Characterization of a cold-active lipase from Psychrobacter cryohalolentis K5T and its deletion mutants

A gene coding for cold-active lipase from the psychrotrophic Gram-negative bacterium Psychrobacter cryohalolentis K5^T isolated from a Siberian cryopeg has been cloned and expressed in Escherichia coli. The recombinant protein Lip1Pc with a 6× histidine tag at its C-terminus was purified by nickel affinity chromatography. With p-nitrophenyl dodecanoate (C12) as a substrate, the purified recombinant protein displayed maximum lipolytic activity at 25°C and pH 8.0. Increasing the temperature above 40°C and addition of various metal ions and organic solvents inhibited the enzymatic activity of Lip1Pc. Most nonionic detergents, such as Triton X-100 and Tween 20, slightly increased the lipase activity, while SDS completely inhibited it. To investigate the functional significance of the Lip1Pc N-terminal domain, we constructed five deletion mutants of this protein. The ND1 and ND2 mutants displayed specific activity reduced by 30–35%, while other truncated proteins were completely inactive. Both mutants demonstrated increased activity towards p-nitrophenyl decanoate (C10) and impaired utilization of C16 substrate. Although optimum reaction temperature of ND2 lowered to 20°C, it displayed enhanced stability by 44% after incubation at 40°C. The results prove that the N-terminal domain of Lip1Pc has a fundamental impact on the activity and stability of the protein.     

Cell Surface Display of Lipase in Pseudomonas putida KT2442 Using OprF as an Anchoring Motif and Its Biocatalytic Applications

We developed a new cell surface display system in Pseudomonas putida KT2442 using OprF, an outer membrane protein of Pseudomonas aeruginosa, as an anchoring motif in a C-terminal deletion-fusion strategy. The Pseudomonas fluorescens SIK W1 lipase gene was fused to two different C-terminal truncated OprF genes, and the fusion genes were cloned into the broad-host-range plasmid pBBR1MCS2 to make pMO164PL and pMO188PL. Plasmid pMO188PL allowed better display of lipase and thus was chosen for further study. The display of lipase on the surface of P. putida KT2442 was confirmed by Western blot analysis, immunofluorescence microscopy, and measurement of whole-cell lipase activity. The whole-cell lipase activity of recombinant P. putida KT2442 harboring pMO188PL was more than fivefold higher than that of recombinant Escherichia coli displaying lipase in the same manner. Cell surface-displayed lipase exhibited the highest activity at 47°C and pH 9.0, and the whole-cell lipase activity was greater than 90% of the initial activity in organic solvents at 47°C for 1 week. In a biocatalytic application, enantioselective resolution of 1-phenyl ethanol was carried out in an organic solvent. (R)-Phenyl ethyl acetate was successfully produced with 41.9% conversion and an enantiomeric excess of more than 99% in a 36-h reaction. These results suggest that the OprF anchor can be used for efficient display of proteins in P. putida KT2442 and consequently for various biocatalytic applications.     

Gene cloning,overexpression and characterization of a novel organic solvent tolerant and thermostable lipase from Galactomyces geotrichum Y05

Although the lipase of Geotrichum candidum has been extensively reported, little attention has been focused on molecular genetic and biochemical characterizations of Galactomyces geotrichum lipases. A lipase gene from G. geotrichum Y05 was cloned from both genomic DNA and cDNA sources. Nucleotide sequencing revealed that the ggl gene has an ORF of 1692 bp without any introns, encoding a protein of 563 amino acid residues, including a potential signal sequence of 19 amino acid residues. The amino acid sequence of this lipase showed 86% identity to lipase of Trichosporon fermentans WU-C12. The mature lipase gene was subcloned into pPIC9K vector, and overexpressed in methylotrophic Pichia pastoris GS115. Active lipase was accumulated to the level of 100.0 U/ml (0.4 mg/ml) in the shake-flask culture, 10.4-fold higher than the activity of the original strain (9.6 U/ml). This yield dramatically exceeds that previously reported with 23–50 U/ml, 0.06 mg/ml and 0.2 mg/ml. The purified lipase exhibited several properties of significant industrial importance, such as pH and temperature stability, wide organic solvent tolerance and broad hydrolysis on vegetable oils. Such a combination of properties makes it a promising candidate for its application in non-aqueous biocatalysis, such as biodiesel production, selective hydrolysis or esterification for enrichment of PUFAs and oil-contaminated biodegradation, which have been drawn considerable attention currently.     

Gene Cloning,Expression, and Characterization of the <Emphasis Type="Italic">Geobacillus Thermoleovorans</Emphasis> CCR11 Thermoalkaliphilic Lipase

The gene for a Geobacillus thermoleovorans CCR11 thermostable lipase was recovered by PCR and cloned. Four genetic constructions were designed and successfully expressed in E. coli: (i) the lipase structural gene (lipCCR11) in the PinPoint Xa vector; (ii) the lipase structural gene (lipACCR11) in the pET-28a(+) vector; (iii) the lipase structural gene minus the signal peptide (lipMatCCR11) in the pET-3b vector; and (iv) the lipase structural gene plus its own promoter (lipProCCR11) in the pGEM-T cloning vector. The lipase gene sequence analysis showed an open reading frame of 1,212 nucleotides coding for a mature lipase of 382 residues (40 kDa) plus a 22 residues signal peptide. Expression under T7 and T7lac promoter resulted in a 40- and 36-fold increase in lipolytic activity with respect to the original strain lipase. All recombinant lipases showed an optimal activity at pH 9.0, but variations were found in the temperature for maximum activity and the substrate specificity among them and when compared with the parental strain lipase, especially in the recombinant lipases that contained fusion tags. Therefore, it is important to find the appropriate expression system able to attain a high concentration of the recombinant lipase without compromising the proper folding of the protein.     

Identification of lipase encoding genes from Antarctic seawater bacteria using degenerate primers: Expression of a cold-active lipase with high specific activity

Cold-active enzymes are valuable catalysts showing high activity at low and moderate temperatures and low thermostability. Among cold-active enzymes, lipases offer a great potential in detergent, cosmetic, biofuel and food or feed industries. In this paper we describe the identification of novel lipase coding genes and the expression of a lipase with high activity at low temperatures. The genomic DNA from Antarctic seawater bacteria showing lipolytic activity at 4 °C was used to amplify five DNA fragments that partially encode novel lipases using specifically designed COnsensus-DEgenerate Hybrid Oligonucleotide Primers (CODEHOP). All the fragments were found to have a high identity with an α/β-hydrolase domain-containing protein identified by the sequencing of the complete genome of Shewanella frigidimarina NCIMB 400. The complete sequence of one of the lipase-coding gene fragments, lipE13, was obtained by genome walking. Considering that the other fragments had a high identity to the putative lipase from S. frigidimarina NCIMB 400, the complete lipase genes were amplified using oligonucleotide primers designed based on the 5′ and 3′ regions of the coding sequence of the related protein.This strategy allowed the amplification of 3 lipase-encoding genes of which one was expressed in the periplasm using the Escherichia coli BL21(DE3)/pET-22b(+) expression system. The recombinant protein was obtained with activity toward p-nitrophenyl caproate showing a high specific activity between 15 and 25 °C.     

Cloning and expression of novel lipase from entomopathogenic fungi,Beauveria bassiana

Lipase, which catalyzes the hydrolysis of triacylglycerol, is one of the enzymes of interest in the bio-industry. In this study, strains of entomopathogenic fungi were screened for their lipase activity and the characteristics of lipase isolated from Beauveria bassiana JEF-351 strain showing high lipase activity were investigated. Lipase gene of B. bassiana JEF-351 strain, BBL351, was introduced into the genome of Autographa californica nucleopolyhedrovirus (AcMNPV) and recombinant lipases were expressed as non-secreted and secreted protein, respectively. Enzyme activity of BBL351 was higher when the protein was expressed as secreted form, demonstrating that post-translational modification such as glycosylation is crucial for enzyme activity. In addition, the enzyme activity of BBL351 was higher than that of CML, which is an sn-1(3) regioselective lipase reported from Cordyceps militaris. These results suggested that the lipase derived from the B. bassiana JEF-351 strain could be useful as biocatalyst in the biotechnological applications.     

Binding of phage displayed Bacillus subtilis lipase A to a phosphonate suicide inhibitor

Phage display can be used as a protein engineering tool to select proteins with desirable binding properties from a library of randomly constructed mutants. Here, we describe the development of this method for the directed evolution of Bacillus subtilis lipase A, an enzyme that has marked properties for the preparation of pharmaceutically relevant chiral compounds. The lipase gene was cloned upstream of the phage g3p encoding sequence and downstream of a modified g3p signal sequence. Consequently, the enzyme was displayed at the surface of bacteriophage fd as a fusion to its minor coat protein g3p. The phage-bound lipase was correctly folded and fully enzymatically active as determined from the hydrolysis of p-nitrophenylcaprylate with K(m)-values of 0.38 and 0.33 mM for the phage displayed and soluble lipase, respectively. Both soluble lipase and lipase expressed on bacteriophages reacted covalently with a phosphonate suicide inhibitor. The phage does not hamper lipase binding, since both soluble and phage-bound lipase have a similar half-life of inactivation of approximately 5 min. Therefore, we conclude that the Bacillus lipase can be functionally expressed on bacteriophages as a fusion to the phage coat protein g3p. The specific interaction with the suicide inhibitor offers a fast and reproducible method for the future selection of mutant enzymes with an enantioselectivity towards new substrates.     

de novo Design and Synthesis of Candida antarctica Lipase B Gene and α-Factor Leads to High-Level Expression in Pichia pastoris

Candida antarctica lipase B (CALB) is one of the most widely used and studied enzymes in the world. In order to achieve the high-level expression of CALB in Pichia, we optimized the codons of CALB gene and α-factor by using a de novo design and synthesis strategy. Through comparative analysis of a series of recombinants with different expression components, we found that the methanol-inducible expression recombinant carrying the codon-optimized α-factor and mature CALB gene (pPIC9KαM-CalBM) has the highest lipase production capacity. After fermentation parameters optimization, the lipase activity and protein content of the recombinant pPIC9KαM-CalBM reached 6,100 U/mL and 3.0 g/L, respectively, in a 5-L fermentor. We believe this strategy could be of special interest due to its capacity to improve the expression level of target gene, and the Pichia transformants carrying the codon-optimized gene had great potential for the industrial-scale production of CALB lipase.