Lipase is a kind of widely used hydrolase.Surface display is an efficient method of highthroughput screening for protein engineering of lipase.Besides,lipase displaying on surface of microorganism has many advantages,such as higher stability against high temperature and organic solvent,compared with free lipase,so the host strain displaying lipase can be used as wholecell biocatalyst,which has some advantages compared with traditional immobilization of lipase.There are three kinds of host strain for displaying lipase:phage,bacteria and yeast.The surface display of lipase in the three display systems were systematically discribed,and their current uses and possible trends in the future were discussed also.

Objective To investigate the relationship between CYP2J2*7 mutation(G-76T) and coronary heart disease (CHD) in Chinese Hanpopulation and to study the effects of CYP2J2 geneover-expressionon the proliferation and migrationof aortic smooth muscle cells of ApoE-/- mice. Methods CYP2J2*7 genotype was detectedin 500 patients with CHD and 478 controlsubjects by the Polymerase Chain Reaction-Restriction Frag-ment Length Polymorphism (PCR-RFLP). Culturedaortic smooth muscle cells of ApoE-/- mice were divided into control group, sham transfectiongroup and CYP2J2 over-expression group. Cell proliferation and migration were investigated after CYP2J2 over-expressionby MTS and Transwell assay. Results The frequency of CYP2J2*7 in CHD group was significantly higher than that incontrol group (10.00% vs. 6.49%, P = 0.046). Same is the case in female cases(P = 0.026). Compared with these of aortic smooth muscle cells incontrol group and sham trans-fectiongroup, the cell proliferation in 24, 48, 72 h, and the cell migration in 48 h after CYP2J2 over-expression in CYP2J2 group were significantly suppressed. Conclusions CYP2J2*7 mutation might increase the risk of CHD in Chinese Han population. CYP2J2 over-expression can suppress the proliferation and migration of aortic smooth muscle cells and CYP2J2 might have the effect of anti-atherosclerosis.

Through introducing mutations into ribosomes by obtaining spontaneous drug resistance of microorganisms, ribosome engineering technology is an effective approach to develop mutant strains that overproduce secondary metabolites. In this study, ribosome engineering was used to improve the yield of butenyl-spinosyns produced by Saccharopolyspora pogona by screening streptomycin resistant mutants. The yields of butenyl-spinosyns were then analyzed and compared with the parent strain. Among the mutants, S13 displayed the greatest increase in the yield of butenyl-spinosyns, which was 1.79 fold higher than that in the parent strain. Further analysis of the metabolite profile of S13 by mass spectrometry lead to the discovery of Spinosyn α1, which was absent from the parent strain. DNA sequencing showed that there existed two point mutations in the conserved regions of rpsL gene which encodes ribosomal protein S12 in S13. The mutations occurred a C to A and a C to T transversion mutations occurred at nucleotide pair 314 and 320 respectively, which resulted in the mutations of Proline (105) to Gultamine and Alanine (107) to Valine. It also demonstrated that S13 exhibited genetic stability even after five passages.
Genetic Engineering ; Macrolides ; metabolism ; Point Mutation ; Ribosomal Proteins ; genetics ; Ribosomes ; metabolism ; Saccharopolyspora ; metabolism

Objective To explore the anatomic positional relationship of bronchial artery(BA)with esophagus and main bronchus on 320-detector CTA.Methods Original and post-processed images of 142 patients were observed.Type,origin,opening direction of BA as well as its concomitant relationship with esophagus were recorded.The positional relationship of BA with main bronchus was also recorded by fusing the images of BA and bronchial tree together.Results In 122 patients,273 BA were identified (146 on the right and 127 on the left).Right BA mainly ran simultaneously along the right and posterior edge of the esophagus (49.3%),while left BA mainly ran far gradually on the left side of the esophagus (82.7%).The left and right BA mainly ran along the middle thoracic esophagus, accounting for 58.3% and 42.5% respectively.45.2% of the right BA ran across the posterior edge of the right main bronchus and 60.6% of left BA ran simultaneously on the posterior and up edge of the esophagus.The most dividing direction of BA from the tho-racic aorta was 9 to 12 o’clock with a frequency of 74.2%.Conclusion The concomitant relationship with esophagus of the BA and the positional relationship with main bronchus of the BA could clearly be demonstrated on 320-detector CTA,thus providing availa-ble information and help for pulmonary and mediastinal sugery.

Aspergillus niger lipases are important biocatalysis widely used in industries for food processing and pharmaceutical preparation. High-level expression recombinants can lead to cost effective lipase large scale production. Full length gene synthesis is an efficient measure to enhance the expression level of the gene. In order to reduce the non-specific binding between oligonucleotides and bases mutation caused by the complicate secondary structure of DNA and excessive PCR amplification, a frequently phenomenon in one-step gene synthesis, we used a two-step method including assembly PCR (A-PCR) and digestion-ligation step to synthesis Aspergillus niger lipase gene lipA. Assisted by DNA2.0 and Gene2Oliga software, we optimized the codon usage and secondary structure of RNA and induced enzyme sites Cla I (237 site) and Pst I (475 site) into the gene. In the first step, fragments F1 (237 bp), F2 (238 bp) and F3 (422 bp) were separately synthesized by assembly PCR. In the second step, fragments F1, F2 and F3 were separately digested by Cla I and Pst I, and then ligated into a full length lipA gene. Two-step method efficiently enhanced successful ratio for full-length gene synthesis and dispersed the risk for gene redesign. The synthesized gene was cloned into pPIC9K vector and transferred into Pichia pastoris. After methanol inducement, the expression level of the codon optimized lipA-syn gene reached 176.0 U/mL, 10.8-fold of the original lipA gene (16.3 U/mL) in Pichia pastoris GS1115. The recombinant offers the possibility for lipase large-scale production.
Base Sequence ; Carboxylic Ester Hydrolases ; biosynthesis ; genetics ; Cloning, Molecular ; Genes, Synthetic ; Genetic Engineering ; methods ; Genetic Vectors ; genetics ; Molecular Sequence Data ; Pichia ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics

In order to realize over-expression of Burkholderia cepacia (B. cepacia) lipase, we introduced the widely used T7 RAN polymerase expression system into B. cepacia G63 to over-express the lipase gene. By using PCR technique, we amplified the T7 RNA polymerase gene (T7 RNAP) from the BL21 (DE3) and cloned it into the suicide plasmid pJQ200SK. After that, we flanked T7 RNAP with two 500 bp homologous fragments and integrated it into the genomes of B. cepacia by tri-parental mating, so that T7 RNAP was under-controlled by lipase gene (lipA) promoter. Then, we cloned the lipA and its partner gene lipB into the vector pUCPCM and pBBR22b both or separately. Therefore, we got 7 expression plasmids pBBR22blipAB, pBBR22blipA, pUCPCMlipAB, pUCPCMlipA, pUCPCMdeltalipAlipB, pUCPCMdeltalipA, pUCPCMdeltalipB, and then electroporated them into B. cepacia containing T7 RNA. After shake flask culture, we found B. cepacia containing pUCPCMlipAB produced the most quantity of lipase, and lipase activity was up to 607.2 U/mg, 2.8-folds higher than that of the wild strain. Moreover, lipase activities of all engineering strains except the one containing pUCPCMdeltalipB were enhanced to some extent. The specific activities of wild type B. cepacia and B. cepacia containing pUCPCMlipAB were respectively 29 984 U/mg and 30 875 U/mg after ammonium sulfate precipitation and gel filtration chromatography. The T7 RNA polymerase expression system could effectively enhanced lipase expression in B. cepacia, and secretion signal PelB and ribosome-binding site may promote lipase expression in engineering strain.
Bacteriophage T7 ; genetics ; Burkholderia cepacia ; enzymology ; genetics ; Cloning, Molecular ; DNA-Directed RNA Polymerases ; genetics ; Escherichia coli ; enzymology ; genetics ; Lipase ; biosynthesis ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Transformation, Genetic ; Viral Proteins ; genetics

Random mutagenesis on Bacillus pumilus lipase YZ02 gene was conducted by using error-prone PCR strategy. Through two cycles of directed evolution, two optimum mutants BpL1-7 and BpL2-1369 with lipase activity improved 2 folds and 6 folds respectively were screened. The sequence of BpL2-1369 lipase gene showed that four nucleotides substitution, T61C, C147T, A334G and T371A have occurred, and three of them caused amino acid changes. Thus, amine acid Ser21 was changed into Pro21, Arg112 to Gly112, and Leu124 to His124. According to the 3D structure of Bacillus pumilus lipase mimicked by SWISS-MODEL Repository, three mutated amino acids were located at the third amino acid of the first alpha-helix, the turn between the fourth and fifth beta fold, and the first amino acid of the fifth beta fold, respectively. The BpL and BpL2-1369 genes were ligated into pET28a vector, and transferred into E. coli BL21 (DE3). After induced by IPTG the lipases were purified and characterized. The results showed that the specific activity of the evolved lipase was 1.31-fold than that of the wild lipase, and the Km decreased from 8.24 mmol/L to 7.17 mmol/L. The pH stability of the evolved lipase was better than wild lipase when pH>8.0.
Bacillus ; enzymology ; genetics ; Directed Molecular Evolution ; Lipase ; chemistry ; genetics ; metabolism ; Point Mutation ; Polymerase Chain Reaction ; methods ; Protein Engineering ; Sequence Analysis, Protein

Yarrowia lipolytica lipase Lip2 (YlLip2) is an important industrial enzyme with many potential applications. To alleviate the dissolved oxygen (DO) limitation and improve YlLip2 production during high-cell density fermentation, the YlLip2 gene lip2 and Vitreoscilla hemoglobin (VHb) gene vgb were co-expressed in Pichiapastoris under the control of AOX1 and PsADH2 promoter, respectively. The PsADH2 promoter from Pichia stipitis could be activated under oxygen limitation. The SDS-PAGE and CO-difference spectrum analysis indicated that VHb and YlLip2 had successfully co-expressed in recombinant strains. Compared with the control cells (VHb-, GS115/9Klip2), the expression levels of YlLip2 in VHb-expressing cells (VHb+, GS115/9Klip2-pZPVT) under oxygen limitation were improved 25% in shake-flask culture and 83% in a 10 L fermentor. Moreover, the VHb+ cells displayed higher biomass than VHb- cells at lower DO levels in a 10 L fermentor. In this study, we also achieved a VHb-expressing clone harboring multicopy lip2 gene (GS115/9Klip2-pZPVTlip2 49#), which showed the maximum lipolytic activity of 33 900 U/mL in a 10 L fermentor under lower DO conditions. Therefore, it can be seen that expression of VHb with PsADH2 promoter in P. pastoris combined with increasing copies of lip2 gene is an effective strategy to improve YlLip2 production.
Bacterial Proteins ; biosynthesis ; genetics ; Fermentation ; Fungal Proteins ; biosynthesis ; genetics ; Lipase ; biosynthesis ; genetics ; Oxygen ; analysis ; pharmacology ; Pichia ; metabolism ; Protein Engineering ; Recombinant Proteins ; biosynthesis ; genetics ; Truncated Hemoglobins ; biosynthesis ; genetics

Vegetable oil is one of the most potential alternatives of petroleum and has become a hot issue in recent years. This review focuses on the influence of vegetable oil structure on platform compounds and polymers properties, and further systematically introduces their developments and the latest progress. Meanwhile, we also summarized the main confronting problems and the future development directions in the research of oil-based platform compounds and polymers. The review provides useful information for readers to fully understand biochemical engineering of vegetable oils and their prospects.

The adhesive protein secreted by marine sessile animals can resist the resistance of water and exert stickiness under the humid environment. It has become a candidate for the development of high-performance materials in the field of biomedicine and bionics. Barnacles are as one of the marine macrofoulers that can be firmly attached to the underwater substrate materials with different surface characteristics through its cement proteins. To date, the adhesion process of barnacle has been understood in-depth, but the specific underwater adhesion mechanism has not been elucidated and needs further exploration. This review first presented an overview of barnacle and its adhesion process, followed by summarizing the advances of barnacle adhesive protein, its production methods, and applications. Moreover, challenges and future perspectives were prospected.
Animals ; Thoracica/metabolism* ; Proteins/metabolism* ; Adhesives/metabolism*