Protein secretion plays an important role in bacterial lifestyles. In Gram-negative bacteria, a wide range of proteins are secreted to modulate the interactions of bacteria with their environments and other bacteria v...Protein secretion plays an important role in bacterial lifestyles. In Gram-negative bacteria, a wide range of proteins are secreted to modulate the interactions of bacteria with their environments and other bacteria via various secretion systems. These proteins are essential for the virulence of bacteria, so it is crucial to study them for the pathogenesis of diseases and the development of drugs. Using amino acid composition (AAC), position-specific scoring matrix (PSSM) and N-terminal signal peptides, two different substitution models are firstly constructed to transform protein sequences into numerical vectors. Then, based on support vector machine (SVM) and the “one to one”?algorithm, a hybrid multi-classifier named SecretP v.2.2 is proposed to rapidly and accurately?distinguish different types of Gram-negative?bacterial secreted proteins. When performed on the same test set for a comparison with other methods, SecretP v.2.2 gets the highest total sensitivity of 93.60%. A public independent dataset is used to further test the power of SecretP v.2.2 for predicting NCSPs, it also yields satisfactory results.展开更多
Fusobacterium nucleatum is an anaerobic, commensal, gram-negative oral bacterium that is carcinogenic and causes a wide range of human diseases. The present study focused on the analysis of the hypothetical protein, H...Fusobacterium nucleatum is an anaerobic, commensal, gram-negative oral bacterium that is carcinogenic and causes a wide range of human diseases. The present study focused on the analysis of the hypothetical protein, HMPREF3221_01179, derived from F. nucleatum strain MJR7757B, employing various computational methods to anticipate both its structure and functional characteristics. NCBI conserved domain analysis, NCBI BLASTp and MEGA Phylogenetic tree study characterize the target protein as an outer membrane efflux protein (ToIC family) which facilitate the bacterial transmembrane transport. With a molecular weight of 52120.02 Da, an isoelectric point (pI) of 8.33, and an instability index of 29.47, the protein is anticipated to exhibit good solubility in the extracellular space and crucial stability for pharmaceutical applications. The protein’s structure meets quality standards during the construction and refinement of its 3D model. The efflux inhibitor Arginine beta-naphthylamide exhibits a significant binding affinity (-7.1 kcal/mol) to the binding site of the target protein. The in-silico analysis improves the understanding of the protein and facilitates future investigations into therapeutic medication.展开更多
The internal region of bacterial translocatable IS1 acts as a cis-element to stimulate transcription from the various promoters located upstream. The product of the artA gene is genetically shown to stimulate transcri...The internal region of bacterial translocatable IS1 acts as a cis-element to stimulate transcription from the various promoters located upstream. The product of the artA gene is genetically shown to stimulate transcription with the cis-element. Here, a codon-optimized artA gene was synthesized and cloned to express the ArtA protein. ArtA was purified as the Histagged protein. Nitrocellulose filter binding assay showed that ArtA specifically binds to the IS1 internal region. Electrophoretic mobility shift assay also showed specific binding of ArtA to the IS1 internal region. These results imply that ArtA directly binds to the IS1 internal region and stimulates transcription.展开更多
The insecticidal protein produced by Pseudomonas pseudoalcaligenes is purified from the suspension of the bacterial culture. As an intact molecule, the protein acts on the foregut, midgut, hindgut, vasa Malpighii and ...The insecticidal protein produced by Pseudomonas pseudoalcaligenes is purified from the suspension of the bacterial culture. As an intact molecule, the protein acts on the foregut, midgut, hindgut, vasa Malpighii and fat body, and kills locusts. The disinsection rates of feeding and injection are 63.3% and 65.7%, respectively. After 24h to 48h, it is observed that all these tissues and cells show pathological changes in varying degrees, and so did the host cellular organs of these cells, such as cytoblast, mitochondria, endoplasmic reticulum and ribosome. Particularly, the changes of the mitochondria are much more serious than those of others. Detection of oxygen electrode shows the efficiency of oxidative phosphorylation and the ATP synthesis decreases, while the activity of mitochondrial ATPase is almost not affected. That means the energy utilization of locusts is in gear, but the shortage of the supplying of energy results in their death. This research forms the substantial basis for controlling locusts.展开更多
Mucosal immunity plays an important role in protecting pigs against transmissible gastroenteritis virus （TGEV） infection. To elicit mucosal immune response against TGEV, we developed a surface antigen display system...Mucosal immunity plays an important role in protecting pigs against transmissible gastroenteritis virus （TGEV） infection. To elicit mucosal immune response against TGEV, we developed a surface antigen display system using the poly-γ- glutamate synthetase A （pgsA） protein of Bacillus subtilis as an anchoring matrix to express recombinant fusion proteins of pgsA and nucleocapsid protein of TGEV in Lactobacillus casei. Surface location of fusion protein was verified by ELISA and indirect immunofluorescence test. Oral and intranasal inoculations of pregnant sow and mice with recombinant L. casei resulted in high levels of serum immunoglobulin G （IgG） and secretory immunoglobulin A （slgA） against recombinant N protein as demonstrated by ELISA. More importantly, the level of specific slgA in colostrum significantly increased compared with that of IgG. The serum IgG levels of the piglets increased after suckling colostrum produced by sows was previously inoculated with recombinant L. casei. These results indicate that immunization with recombinant L. casei expressing TGEV N protein on its surface elicited high levels of specific slgA and circulating IgG against TGEV N protein.展开更多
Lead contamination still remains as serious threat to public health and environment because of its non-biodegradability and toxicity. A clean technique has been developed for removal of lead contamination through the ...Lead contamination still remains as serious threat to public health and environment because of its non-biodegradability and toxicity. A clean technique has been developed for removal of lead contamination through the formation of lead-oxide nanoplates using a bacterial protein (Molecular weight ~30 kDa) as biological template. The isolated hot-spring bacterial (the bacterium was named as MDH1) protein when adding to the solution of lead compound (e.g., lead nitrate), nanoplates of lead-oxide are formed as viewed by electron microscope. The as prepared lead-oxide-nanoplates are characterized by Inductively Coupled Plasma analysis, Energy Dispersive X-ray Spectroscopy and X-ray diffraction analyses. The lead-oxide-nanoplates and the filtered supernatant of the reactive solution both were separately used to observe the inhibition of growth of <i>E. coli</i> bacteria on culture plate. Lead-oxide-nanoplates produced clear zone of inhibition on the bacterial growth plate, whereas the filtered supernatant exhibited no such zone on the growth of <i>E. coli</i> bacteria revealing the fact that lead contamination was removed from the filtered supernatant. The prepared lead oxide nanoplates also possess dye degradation activity which is the added advantage of the process. The MDH1 bacterial protein acts as biological template which successfully removes lead contamination from lead-solution. The process is a clean and cost-effective one which can be used not only for removal of lead contamination but also for removal of different dyes from environment due to having dye-degradation attribute of the lead-oxide nanoplates.展开更多
The purpose of this study was to measure the amount of adsorption of various salivary proteins to a resin composite having various amounts of surface pre-reacted glass-ionomer (S-PRG) fillers, and to make a comparativ...The purpose of this study was to measure the amount of adsorption of various salivary proteins to a resin composite having various amounts of surface pre-reacted glass-ionomer (S-PRG) fillers, and to make a comparative study of the adherence of S. mutans to the resin composite covered by various salivary proteins. We experimentally produced resin composites (S-PRG resin) having the basic composition of Bis-GMA/TEGDMA and various amount of the S-PRG fillers ranging between 0 - 60 wt%. Each S-PRG resin block was soaked in 5 kinds of components found in salivary fluid (Mucin 1, Lactoferrin, IgA, Cystatin C, and Lysozyme), and the amount of adsorption was measured by use of a spectrophotometer. The amount of the adsorption of salivary Mucin 1 was higher than that of any other salivary component tested regardless of the percentage of the S-PRG filler. In the case of salivary Lysoxyme used for coating, the amount of its adsorption increased with an increase in the percentage of the S-PRG filler. In addition, resin blocks coated with various salivary proteins were incubated at 37℃ for 2 hours with radio-labeled S. mutans for a quantitative adherence test. Labeled bacteria that adhered to the resin blocks were collected by using an automatic sample combustion system and a liquid scintillation counter. The absorbed salivary components, especially Mucin 1 and Lysozyme, inhibited the adhesion of S. mutans to the S-PRG resin;however, these changes were generally directional rather than statistically significant.展开更多
Antagonistic bacterium HJXI is a Bacillus subtilis strain isolated from field rhizasphere soil where banana wih was serious, with certain control efficacy on banana Fusarium wilt. The crude extract obtained from its f...Antagonistic bacterium HJXI is a Bacillus subtilis strain isolated from field rhizasphere soil where banana wih was serious, with certain control efficacy on banana Fusarium wilt. The crude extract obtained from its fermentation broth after ammonium sulfate precipitation has an inhibitory effect on various pathogenic fungi. The culture conditions for this strain were optimized in this study with Fusarium oxysporum f. sp. ettbense as an indicator, and the results showed that the fermentation broth obtained from culture in LB liquid medium under 30 ℃ at 170 r/min for48 h had the strongest inhibition against F. oxysparum f. 8p. cubense. It was observed that the inhibition was mainly reflected by causing breakage and distortion of myeelia, followed by appearance of vesicles and swelling, ablation, and leakage of protoplasm. This study provides a scientific basis for the study on the action mechanism of crude protein from bacterial strain HJX1.展开更多
文摘Protein secretion plays an important role in bacterial lifestyles. In Gram-negative bacteria, a wide range of proteins are secreted to modulate the interactions of bacteria with their environments and other bacteria via various secretion systems. These proteins are essential for the virulence of bacteria, so it is crucial to study them for the pathogenesis of diseases and the development of drugs. Using amino acid composition (AAC), position-specific scoring matrix (PSSM) and N-terminal signal peptides, two different substitution models are firstly constructed to transform protein sequences into numerical vectors. Then, based on support vector machine (SVM) and the “one to one”?algorithm, a hybrid multi-classifier named SecretP v.2.2 is proposed to rapidly and accurately?distinguish different types of Gram-negative?bacterial secreted proteins. When performed on the same test set for a comparison with other methods, SecretP v.2.2 gets the highest total sensitivity of 93.60%. A public independent dataset is used to further test the power of SecretP v.2.2 for predicting NCSPs, it also yields satisfactory results.
文摘Fusobacterium nucleatum is an anaerobic, commensal, gram-negative oral bacterium that is carcinogenic and causes a wide range of human diseases. The present study focused on the analysis of the hypothetical protein, HMPREF3221_01179, derived from F. nucleatum strain MJR7757B, employing various computational methods to anticipate both its structure and functional characteristics. NCBI conserved domain analysis, NCBI BLASTp and MEGA Phylogenetic tree study characterize the target protein as an outer membrane efflux protein (ToIC family) which facilitate the bacterial transmembrane transport. With a molecular weight of 52120.02 Da, an isoelectric point (pI) of 8.33, and an instability index of 29.47, the protein is anticipated to exhibit good solubility in the extracellular space and crucial stability for pharmaceutical applications. The protein’s structure meets quality standards during the construction and refinement of its 3D model. The efflux inhibitor Arginine beta-naphthylamide exhibits a significant binding affinity (-7.1 kcal/mol) to the binding site of the target protein. The in-silico analysis improves the understanding of the protein and facilitates future investigations into therapeutic medication.
文摘The internal region of bacterial translocatable IS1 acts as a cis-element to stimulate transcription from the various promoters located upstream. The product of the artA gene is genetically shown to stimulate transcription with the cis-element. Here, a codon-optimized artA gene was synthesized and cloned to express the ArtA protein. ArtA was purified as the Histagged protein. Nitrocellulose filter binding assay showed that ArtA specifically binds to the IS1 internal region. Electrophoretic mobility shift assay also showed specific binding of ArtA to the IS1 internal region. These results imply that ArtA directly binds to the IS1 internal region and stimulates transcription.
文摘The insecticidal protein produced by Pseudomonas pseudoalcaligenes is purified from the suspension of the bacterial culture. As an intact molecule, the protein acts on the foregut, midgut, hindgut, vasa Malpighii and fat body, and kills locusts. The disinsection rates of feeding and injection are 63.3% and 65.7%, respectively. After 24h to 48h, it is observed that all these tissues and cells show pathological changes in varying degrees, and so did the host cellular organs of these cells, such as cytoblast, mitochondria, endoplasmic reticulum and ribosome. Particularly, the changes of the mitochondria are much more serious than those of others. Detection of oxygen electrode shows the efficiency of oxidative phosphorylation and the ATP synthesis decreases, while the activity of mitochondrial ATPase is almost not affected. That means the energy utilization of locusts is in gear, but the shortage of the supplying of energy results in their death. This research forms the substantial basis for controlling locusts.
基金supported by the fund of the Key Science and Technology Research during the 10th Five-Year-Plan period in Heilongjiang Province, China(GB05B501-2).
文摘Mucosal immunity plays an important role in protecting pigs against transmissible gastroenteritis virus （TGEV） infection. To elicit mucosal immune response against TGEV, we developed a surface antigen display system using the poly-γ- glutamate synthetase A （pgsA） protein of Bacillus subtilis as an anchoring matrix to express recombinant fusion proteins of pgsA and nucleocapsid protein of TGEV in Lactobacillus casei. Surface location of fusion protein was verified by ELISA and indirect immunofluorescence test. Oral and intranasal inoculations of pregnant sow and mice with recombinant L. casei resulted in high levels of serum immunoglobulin G （IgG） and secretory immunoglobulin A （slgA） against recombinant N protein as demonstrated by ELISA. More importantly, the level of specific slgA in colostrum significantly increased compared with that of IgG. The serum IgG levels of the piglets increased after suckling colostrum produced by sows was previously inoculated with recombinant L. casei. These results indicate that immunization with recombinant L. casei expressing TGEV N protein on its surface elicited high levels of specific slgA and circulating IgG against TGEV N protein.
文摘Lead contamination still remains as serious threat to public health and environment because of its non-biodegradability and toxicity. A clean technique has been developed for removal of lead contamination through the formation of lead-oxide nanoplates using a bacterial protein (Molecular weight ~30 kDa) as biological template. The isolated hot-spring bacterial (the bacterium was named as MDH1) protein when adding to the solution of lead compound (e.g., lead nitrate), nanoplates of lead-oxide are formed as viewed by electron microscope. The as prepared lead-oxide-nanoplates are characterized by Inductively Coupled Plasma analysis, Energy Dispersive X-ray Spectroscopy and X-ray diffraction analyses. The lead-oxide-nanoplates and the filtered supernatant of the reactive solution both were separately used to observe the inhibition of growth of <i>E. coli</i> bacteria on culture plate. Lead-oxide-nanoplates produced clear zone of inhibition on the bacterial growth plate, whereas the filtered supernatant exhibited no such zone on the growth of <i>E. coli</i> bacteria revealing the fact that lead contamination was removed from the filtered supernatant. The prepared lead oxide nanoplates also possess dye degradation activity which is the added advantage of the process. The MDH1 bacterial protein acts as biological template which successfully removes lead contamination from lead-solution. The process is a clean and cost-effective one which can be used not only for removal of lead contamination but also for removal of different dyes from environment due to having dye-degradation attribute of the lead-oxide nanoplates.
文摘The purpose of this study was to measure the amount of adsorption of various salivary proteins to a resin composite having various amounts of surface pre-reacted glass-ionomer (S-PRG) fillers, and to make a comparative study of the adherence of S. mutans to the resin composite covered by various salivary proteins. We experimentally produced resin composites (S-PRG resin) having the basic composition of Bis-GMA/TEGDMA and various amount of the S-PRG fillers ranging between 0 - 60 wt%. Each S-PRG resin block was soaked in 5 kinds of components found in salivary fluid (Mucin 1, Lactoferrin, IgA, Cystatin C, and Lysozyme), and the amount of adsorption was measured by use of a spectrophotometer. The amount of the adsorption of salivary Mucin 1 was higher than that of any other salivary component tested regardless of the percentage of the S-PRG filler. In the case of salivary Lysoxyme used for coating, the amount of its adsorption increased with an increase in the percentage of the S-PRG filler. In addition, resin blocks coated with various salivary proteins were incubated at 37℃ for 2 hours with radio-labeled S. mutans for a quantitative adherence test. Labeled bacteria that adhered to the resin blocks were collected by using an automatic sample combustion system and a liquid scintillation counter. The absorbed salivary components, especially Mucin 1 and Lysozyme, inhibited the adhesion of S. mutans to the S-PRG resin;however, these changes were generally directional rather than statistically significant.
基金Supported by Natural Science Foundation of Hainan Province(20158304)
文摘Antagonistic bacterium HJXI is a Bacillus subtilis strain isolated from field rhizasphere soil where banana wih was serious, with certain control efficacy on banana Fusarium wilt. The crude extract obtained from its fermentation broth after ammonium sulfate precipitation has an inhibitory effect on various pathogenic fungi. The culture conditions for this strain were optimized in this study with Fusarium oxysporum f. sp. ettbense as an indicator, and the results showed that the fermentation broth obtained from culture in LB liquid medium under 30 ℃ at 170 r/min for48 h had the strongest inhibition against F. oxysparum f. 8p. cubense. It was observed that the inhibition was mainly reflected by causing breakage and distortion of myeelia, followed by appearance of vesicles and swelling, ablation, and leakage of protoplasm. This study provides a scientific basis for the study on the action mechanism of crude protein from bacterial strain HJX1.
