According to the amino acids sequence of OC-IdeltaD86 gene and Escherichia coli codon usage, we synthesized this gene by overlap extension PCR method with 7 oligonucleotides DNA fragments. The PCR fragment was inserted into pGEM-T-easy vector and the recombined plasmid was named pGEM-T-OC-IdeltaD86. Two oligonucleotides into which the BamH I and Xho I sites were introduced were designed and synthesized based on pGEM-T-OC-IdeltaD86 and pet21b, and the PCR fragment into which the BamH I and Xho I sites were introduced was obtained. After digesting it with BamH I and Xho I, OC-IdeltaD86 gene was cloned into the corresponding sites of pet21b and obtained prokaryotic expression vector pet21b-OC-IdeltaD86. OC-IdeltaD86 gene was expressed in E. coli (BL21(DE3)plysS) after IPTG(Isopropyl beta-D-1-thiogalactopyranoside) inducement for 5 hours. The fusion protein of OC-IdeltaD86:6His gene accounted for 11.4% of total protein and 16.4% of soluble protein, which had been successfully purified by Ni-NTA and concentrated by PEG20000. This protein can effectively inhibit papain activity in vitro and may be used in anti-nematode research in vivo.
Cloning, Molecular ; Cystatins ; biosynthesis ; genetics ; Cysteine Endopeptidases ; metabolism ; Cysteine Proteinase Inhibitors ; genetics ; Escherichia coli ; genetics ; metabolism ; Genes, Plant ; genetics ; Mutation ; Oligonucleotides ; chemical synthesis ; genetics ; Oryza ; genetics ; Papain ; antagonists & inhibitors ; Prokaryotic Cells ; metabolism ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; metabolism

Cystatin, which widely distributed in both tissues and body fluids of animal and plant, was a superfamily of cysteine proteinase inhibitors. It could form activity-inhibitor complexes with cysteine proteinases to inhibit the hydrolytic activity of proteinases. Cystatin played important roles not only in the inhibition of the proteolytic degradation of fish muscle, but also in biological defense systems against invaders. To explore the functions of fish cystatin and the potential values in fish disease prevention and cure, as well as seafood processing, the recombinant yeast strains which could express Chinese sturgeon cystatin were constructed. First, the cystatin cDNA of Chinese sturgeon, which had been PCR modified, was subcloned into yeast integrated vector pPICZaA. After extracted and purified, the recombinant plasmids were linearized by Sac I. The yeast Pichia pastoris GS115 strain was transformed by use of the Lithium Chloride transformation method, and the recombinant cystatin yeast strains got. After 0.5% methanol induction, SDS-PAGE analysis of the culture supernatant indicated that the yield of recombinant cystatin was about 215mg x L(-1) with the percentage about 73.6%. The recombinant cystatin was purified through Q-Sepharose anion-exchange chromatography, and the purity reached about 94.2%. The inhibitory activity of recombinant cystatin was measured by inhibiting the proteinase activity of papain. The results showed that about 1 microg recombinant cystatin could inhibit the activity of 15 microg papain. Heat stability assay results showed that there was a decrease in inhibitory activity of cystatin with the increasing of temperature. When solution of recombinant cystatin was kept at 70 degrees C for 5min, the inhibitory activity reduced fast. While the recombinant cystatin was heated to 90 degrees C for 5min, the inhibitory activity of recombinant cystatin was undetected. The inhibitory activity for recombinant Chinese sturgeon cystatin was higher than that of CPI (cysteine proteinase inhibitor) from seeds of corn, that about 1 microg purified CIP could inhibited the activity of 0.278 microg papain. But the heat stability of recombinant cystatin is lower than that of the corn CPI. The expression level and the activity of recombinant cystatin from yeast Pichia pastoris were higher than those from E. coli. Moreover, recombinant cystatin from Pichia pastoris was easier to separate and purify. This paper reported that recombinant fish cystatin was produced in a highly efficient expression system based on the methylotrophic yeast, further work will focus on the function of recombinant Chinese sturgeon cystatin to resist fish disease and explore the value of cystatin as a food additive to inhibit cysteine proteinases during surimi processing.
Animals ; Cystatins ; genetics ; metabolism ; pharmacology ; Cysteine Proteinase Inhibitors ; genetics ; metabolism ; pharmacology ; Enzyme Activation ; drug effects ; Fish Proteins ; genetics ; metabolism ; Pichia ; genetics ; metabolism ; Polymerase Chain Reaction ; Protein Stability ; Temperature

Efforts on directed evolution of sortase A to optimize its catalytic properties have been undertaken and shown the promise. To facilitate screening of sortase A mutants with expected catalytic properties, a novel ligation efficiency monitoring system, including reporter substrates GFP-LPETG and GGGYK-Biotin, was developed. GFP-LPETG, wild type sortase A, and a recently reported high activity sortase A mutant were prepared recombinantly from Escherichia coli BL21 (DE3). Taking advantage of the newly designed reporter system, the ligation efficiency catalyzed by wild type and mutant form of sortase A could be sensitively monitored via SDS-PAGE directly. Consistent with previous report, the mutant sortase A displayed much higher catalytic activity compared to wild type enzyme, indicating the new reporter system is easily and fast handled and sensitive. The application of this reporter system into systemic screening will facilitate future directed optimization of sortase A.
Aminoacyltransferases ; genetics ; metabolism ; Bacterial Proteins ; genetics ; metabolism ; Biocatalysis ; Biotin ; Cysteine Endopeptidases ; genetics ; metabolism ; Electrophoresis, Polyacrylamide Gel ; Escherichia coli ; Genes, Reporter ; Ligation ; Mutant Proteins ; genetics ; metabolism

Bronchi ; cytology ; metabolism ; Cell Line ; Epithelial Cells ; cytology ; metabolism ; Erythromycin ; pharmacology ; Glutamate-Cysteine Ligase ; genetics ; metabolism ; Glutathione ; genetics ; metabolism ; Humans ; RNA, Messenger ; genetics ; metabolism ; Up-Regulation ; drug effects

The recombinant plasmid carrying the gene encoding 3C protease of Enterovirus 71 (EV71) was constructed, the recombinant protein was then expressed and purified, the functional activity was also measured. Firstly, the 3C protease gene was inserted into pET28a vector, the constructed recombinant plasmid was transformed into E. coli BL21 (DE3) for expression under the induction of IPTG. The expressed protein was purified by affinity chromatography (Ni-NTA) and the N-terminus His-tag was cleaved by enterokinase from 3C protease. The activity of 3C protease was evaluated with fluorescent peptide substrates. It was verified by restriction analysis and sequencing that recombinant plasmid pET28a-3C was constructed correctly and functionally expressed in E. coli BL21 (DE3) resulting in the production of recombinant 3C protease with a size of 22kD. Both His-tag and non-His-tag (cleaved by enterokinase) 3C protease exhibited similar enzyme activity to 3B-3C fluorescent peptide with Km, Vmax and Kcat values of 22 microM, 434nM. Min(-1) and 0.0669 Min(-1), respectively. The optimial pH and temperature were 7.0 and 30-37 degrees C, respectively. The acquirement of recombinant purified 3C protease with high activity has paved the way of further studies on anti-viral inhibitors, structural protein assembly, vaccine development and detection methods of EV71.
Cloning, Molecular ; Cysteine Endopeptidases ; chemistry ; genetics ; metabolism ; Enterovirus A, Human ; enzymology ; genetics ; Escherichia coli ; genetics ; metabolism ; Gene Expression ; Kinetics ; Viral Proteins ; chemistry ; genetics ; metabolism

To investigate the improving effect of inter-chain disulfide formation on protein trans-splicing, we introduce a Cys point mutation at Tyr(664) in heavy chain and at Thr(1826) in light chain of B-domain-deleted FVIII (BDD-FVIII). By co-transfection of COS-7 cell with the two Cys mutated chain genes, the intracellular protein splicing, inter-chain disulfide formation, secreted BDD-FVIII and bioactivity in culture supernatant were observed. The data showed that a strengthened spliced BDD-FVIII with an inter-chain disulfide detected by Western blotting and an elevated secretion of spliced BDD-FVIII (128 +/- 24 ng mL(-1)) compared to control (89 +/- 15 ng mL(-1)), assayed by a sandwich ELISA. A Coatest was performed to assay the secretion of bioactivity in culture supernatant and shown a much higher value (0.94 +/- 0.08 u mL(-1)) compared to that of control (0.62 +/- 0.15 u mL(-1)). It suggests that inter-chain disulfide formation could improve protein trans-splicing based dual-vector delivery of BDD-FVIII gene providing experimental evidence for ongoing in vivo study.
Animals ; COS Cells ; Cercopithecus aethiops ; Cysteine ; genetics ; metabolism ; Disulfides ; metabolism ; Factor VIII ; genetics ; metabolism ; Gene Transfer Techniques ; Genetic Vectors ; Mutation ; Peptide Fragments ; genetics ; metabolism ; Protein Splicing ; Transfection

HC-pro gene of Watermelon Mosaic virus was obtained by RT-PCR was 1371bp in length. It was cloned into pPI(9K, then the eucaryotic recombinant expression plasmid pPIC9K-WHC was constructed. After being linearized with restriction endonuclease Sal I , the recombinant plasmid was transformed into Pichia pastoris GS115 by electroporation. The high copy transformants with Mut+ /His+ phenotype were selected by RT-PCR and screening on G418, MD and MM medium. Induced by methanol for 5 days, the culture supernatant was analyzed by SDS-PAGE, the results showed that a specific protein with a molecular weight of about 66 kD was expressed. Western blot analysis proved that the expression protein could specifically bind to HC-Pro polyclonal antibody. Far western blot analysis proved that the expression protein could bind to coat protein, given support to "bridge" hypothesis that HC-Pro help aphid transmission of non-persistent viruses.
Citrullus ; virology ; Cysteine Endopeptidases ; biosynthesis ; genetics ; Mosaic Viruses ; genetics ; Pichia ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; metabolism ; Viral Proteins ; biosynthesis ; genetics

OBJECTIVETo clone the prtH gene from Porphyromonas gingivalis (P.g) ATCC 33277 and analyze the polymorphism of prtH gene from 5 strains of P.g in order to explore the relationship between P.g and periodontitis.

METHODSUsing PCR, the prtH was amplified and cloned into pGEM-T vector. To illustrate the prtH polymorphism among P.g strains, the genomic DNAs were extracted and screened by PCR with three pairs of specific primers, dot blot and Southern blot hybridization using the biotin-labeled prtH sequence as probe.

RESULTSRecombinant DNA pGEM-T- prtH was verified by restriction endonuclease and sequence assay. Strain W 381 and ATCC 33277 showed the identical results in PCR and hybridization assays, whereas strain ATCC 49417 and 14-3-2 revealed individual hybridization patterns. Strain 47A-1 seemed even not to contain prtH gene.

CONCLUSIONSDifferent prtH gene sequences exist in different P.g strains. This polymorphism may indicate various potential virulent effects during the infection and pathogenesis. Established PCR protocol is sensitive for identification of prtH gene.

Bacterial Proteins ; Blotting, Southern ; Cloning, Molecular ; Cysteine Endopeptidases ; genetics ; DNA, Bacterial ; genetics ; metabolism ; Deoxyribonuclease BamHI ; metabolism ; Deoxyribonuclease HindIII ; metabolism ; Polymorphism, Genetic ; Porphyromonas gingivalis ; genetics ; Species Specificity

OBJECTIVETo detect and compare the activity and intensity of gingipain K (Kgp)-caspase like subdomain in culture medium and cell extract of Porphyromonas gingivalis (Pg) isolates in puberty gingivitis and to reveal the possible association of Kgp with puberty gingivitis.

METHODSThirty-six children of 14 to 17 years old were enrolled in this study. Clinical parameters including gingival index (GI), sulcus bleeding index (SBI) and probing depth (PD) were evaluated. Subgingival plaque samples were collected and Pg isolates were obtained. 16S rRNA PCR was used to confirm Pg clinical isolates. Bacteria were grown in batches of BHI base and harvested at the end of log-phase growth. Culture fractions (culture medium and cell extract) of 10 Pg isolates were performed with SDS-PAGE and Western blot technique using primary antibody against specific Kgp-caspase like subdomain. Activity of Kgp in both samples was detected as well. The data were statistically analyzed using SPSS 11.5 software. The relationship between the Kgp intensity/activity of Kgp and the clinical parameters was statistically analyzed using Spearman correlation coefficient.

RESULTSThere was positive correlation between the intensity/activity of Kgp and the clinical parameters (P < 0.05).

CONCLUSIONSThe Kgp in clinical isolates of Pg from puberty gingivitis is in complicated forms. Caspase-like molecules with low molecular weight may exist as intracellular functional protein molecules which can affect the interaction between Pg and host. Kgp was contributes in certain degree to the pathogenesis of puberty gingivitis.

Adhesins, Bacterial ; genetics ; metabolism ; Adolescent ; Cysteine Endopeptidases ; genetics ; metabolism ; Dental Plaque ; microbiology ; Female ; Gingivitis ; enzymology ; microbiology ; Humans ; Male ; Porphyromonas gingivalis ; genetics ; isolation & purification ; metabolism

BACKGROUND: Sarcoplasmic reticulum calcium ATPase 2a (SERCA2a) is a key protein that maintains myocardial Ca 2+ homeostasis. The present study aimed to investigate the mechanism underlying the SERCA2a-SUMOylation (small ubiquitin-like modifier) process after ischemia/reperfusion injury (I/RI) in vitro and in vivo . METHODS: Calcium transient and systolic/diastolic function of cardiomyocytes isolated from Serca2a knockout (KO) and wild-type mice with I/RI were compared. SUMO-relevant protein expression and localization were detected by quantitative real-time PCR (RT-qPCR), Western blotting, and immunofluorescence in vitro and in vivo . Serca2a-SUMOylation, infarct size, and cardiac function of Senp1 or Senp2 overexpressed/suppressed adenovirus infected cardiomyocytes, were detected by immunoprecipitation, triphenyltetrazolium chloride (TTC)-Evans blue staining, and echocardiography respectively. RESULTS: The results showed that the changes of Fura-2 fluorescence intensity and contraction amplitude of cardiomyocytes decreased in the I/RI groups and were further reduced in the Serca2a KO + I/RI groups. Senp1 and Senp2 messenger ribose nucleic acid (mRNA) and protein expression levels in vivo and in cardiomyocytes were highest at 6 h and declined at 12 h after I/RI. However, the highest levels in HL-1 cells were recorded at 12 h. Senp2 expression increased in the cytoplasm, unlike that of Senp1. Inhibition of Senp2 protein reversed the I/RI-induced Serca2a-SUMOylation decline, reduced the infarction area, and improved cardiac function, while inhibition of Senp1 protein could not restore the above indicators. CONCLUSION I/RI activated Senp1 and Senp2 protein expression, which promoted Serca2a-deSUMOylation, while inhibition of Senp2 expression reversed Serca2a-SUMOylation and improved cardiac function.
Animals ; Mice ; Calcium/metabolism* ; Cysteine Endopeptidases/metabolism* ; Myocardial Reperfusion Injury/metabolism* ; Myocardium/metabolism* ; Myocytes, Cardiac/metabolism* ; Proteins/metabolism* ; Sarcoplasmic Reticulum Calcium-Transporting ATPases/genetics*