A short-term efficacy evaluation of biological antibacterial peptides in the adjuvant therapy of stageⅢ periodontitis / 口腔医学

Objective@#To investigate the efficacy of antibacterial peptides in the adjuvant therapy of stage Ⅲ periodontitis.@*Methods@#Fifty-one patients were randomly divided into simple mechanical curettage group, minocycline hydrochloride group and antibacterial peptide group according to the treatment mode. Three groups received periodontal sequential treatment, and after the ultrasonic supragingival scaling, they were performed with curettage, root surface planing, polishing and flushing. After treatment in the minocycline hydrochloride group and the biological antibacterial peptide group, minocycline hydrochloride ointment and biological antibacterial peptide periodontal gel were injected into the periodontal pocket respectively. The mechanical curettage group did not take medicine. Periodontal checklists at baseline and 90 d after treatment were recorded to compare differences of the three groups in periodontal probing depth (PD), bleeding index (BI) and attachment level (AL). Enzyme-linked immunosorbent assay (ELSIA) was used to detect the change of tumour necrosis factor-α (TNF-α), interleukin (IL)-1β by collecting the gingival crevicular fluid of the three sets at baseline, 7 d after treatment and 90 d after treatment. @*Results@#There was no statistically significant difference in periodontal clinical examination indexes(PD,BI,AL) and contents of TNF-α and IL-1β in the gingival crevicular fluid between the three groups at baseline (P>0.05). At 7 and 90 d after treatment, all indexes in the three groups were improved compared with those before treatment. The comparison between groups showed that in periodontal pockets with PD≤5 mm, there was no statistically significant difference in the indicators between the three groups. In periodontal pockets with PD≥6 mm, the minocycline hydrochloride group and the bio-antibacterial peptide group had no statistically significant difference in various indicators, but they were all better than the mechanical scaling group.@*Conclusion@#Basic periodontal therapy is an important treatment for stage Ⅲ periodontitis. Minocycline hydrochloride and biological antibacterial peptides are both effective adjuvant drugs for deep periodontal pockets with PD≥6 mm.

Research progress on root canal irrigation disinfection drugs / 口腔疾病防治

@#Endodontic infection control is crucial to successful root canal treatment. Irrigation is the key step in endodontic procedures, and the application of root canal irrigation and disinfection medications play an important role. How to enhance antibacterial effects and functions in removing tissues while maintaining biocompatibility is a hot topic in endodontics. Currently, insights to address this issue can be split into two categories: one, the modification or combination of conventional endodontic irrigation solutions, and two, the development of novel endodontic irrigation solutions with new technologies and materials, for instance, nanomaterials and natural exacts. However, conventional endodontic irrigation solutions, such as sodium hypochlorite and chlorhexidine, are still the first choice in clinical practice. Most novel endodontic irrigation solutions remain at the pre-clinical laboratory stage. Clinical research and relevant data are required to determine whether various methods can improve endodontic irrigation. From basic research to clinical application is the direction for advancing to the next stage. The present article focuses on research progress on endodontic irrigation, especially concerning its antibacterial mechanism, characteristics and efficacy, to provide a reference for future clinical translation.

Molecular design, pharmacology and toxicology optimization of antimicrobial peptide from Hydrophis cyanocinctus, Hc-CATH / 生物工程学报

Based on the cathelicidin family antimicrobial peptide Hc-CATH derived from sea snake, the Hc-16 and Hc-15 of 16 and 15 amino acid residues, were designed. By using CCK8, minimal inhibitory concentration, ELISA and bio-layer interferometry assays, their cytotoxicity, antibacterial activity, anti-inflammatory activity, and LPS neutralization activity was examined. Compared with Hc-15, Hc-16 had lower cytotoxicity and better broad-spectrum antibacterial activity against pathogens including clinically resistant bacteria, with the minimum inhibitory concentration of only 4.69 μg/mL. Hc-16 inhibited the expression of inflammatory cytokines of TNF-α and IL-6 induced by LPS, so as to significantly reduce the inflammatory response induced by infection. In addition, structure-activity relationship studies have shown that the phenylalanine at the C- and N-terminals of Hc-16 played a crucial role in its antibacterial and anti-inflammatory activity. Altogether, the designed Hc-16 has an excellent prospect to be developed into a novel antibiotic.

Clinical significance of antibacterial peptide LL-37 in early diagnosis of patients with sepsis in emergency department / 中华危重病急救医学

Objective To discuss the clinical significance of antibacterial peptide LL-37 in the early diagnosis of patients with sepsis in emergency department. Methods Forty patients diagnosed with sepsis in the emergency department of the Affiliated Hospital of Zunyi Medical College from December 2017 to March 2018 were enrolled as sepsis group. Twenty healthy volunteers were enrolled contemporaneously in our hospital at medical center as healthy control group. Peripheral blood was collected immediately after diagnosis in sepsis group or during physical examination in healthy control group. The expression of antibacterial peptide LL-37 was determined by enzyme-linked immunosorbent assay (ELISA). Meanwhile, serum procalcitonin (PCT) and C-reactive protein (CRP) levels were determined. The differences in antibacterial peptide LL-37, PCT and CRP levels between the two groups were compared. Pearson correlation method was used to analyze the correlation between antibacterial peptide LL-37, PCT and CRP. Receiver operating characteristic (ROC) curve was drawn, and the early individually or jointly diagnostic value of each detected index for sepsis was analyzed. Results The levels of antimicrobial peptide LL-37, PCT and CRP in peripheral blood of sepsis group were significantly higher than those of healthy control group [LL-37 (μg/L): 1.34±0.69 vs. 0.10±0.06, PCT (μg/L): 46.67±39.51 vs. 0.03±0.02, CRP (mg/L): 129.68±49.83 vs. 3.16±2.85], with statistically significant differences (all P < 0.05). Pearson correlation analysis showed that the expression of antimicrobial peptide LL-37 was positively correlated with PCT and CRP levels (r1 = 0.835, r2 = 0.932, both P < 0.01). ROC curve analysis showed that the area under ROC curve (AUC) of LL-37, PCT and CRP for early diagnosis of sepsis was 0.885, 0.963 and 0.983, respectively, and the AUC of combined diagnosis of the three parameters was as high as 0.994, indicating that the value of combined diagnosis of sepsis was greater than that of single diagnosis; when the combined prediction probability of the three parameters was 0.92, the sensitivity was 97.5%, and the specificity was 95.0%. Conclusion Antibacterial peptide LL-37 has certain clinical value in early diagnosis of patients with sepsis, which can be used as early routine monitoring indicators for patients with early sepsis when combined with PCT and CRP.

Clinical significance of antibacterial peptide LL-37 in early diagnosis of patients with sepsis in emergency department / 中华危重病急救医学

Objective@#To discuss the clinical significance of antibacterial peptide LL-37 in the early diagnosis of patients with sepsis in emergency department.@*Methods@#Forty patients diagnosed with sepsis in the emergency department of the Affiliated Hospital of Zunyi Medical College from December 2017 to March 2018 were enrolled as sepsis group. Twenty healthy volunteers were enrolled contemporaneously in our hospital at medical center as healthy control group. Peripheral blood was collected immediately after diagnosis in sepsis group or during physical examination in healthy control group. The expression of antibacterial peptide LL-37 was determined by enzyme-linked immunosorbent assay (ELISA). Meanwhile, serum procalcitonin (PCT) and C-reactive protein (CRP) levels were determined. The differences in antibacterial peptide LL-37, PCT and CRP levels between the two groups were compared. Pearson correlation method was used to analyze the correlation between antibacterial peptide LL-37, PCT and CRP. Receiver operating characteristic (ROC) curve was drawn, and the early individually or jointly diagnostic value of each detected index for sepsis was analyzed.@*Results@#The levels of antimicrobial peptide LL-37, PCT and CRP in peripheral blood of sepsis group were significantly higher than those of healthy control group [LL-37 (μg/L): 1.34±0.69 vs. 0.10±0.06, PCT (μg/L): 46.67±39.51 vs. 0.03±0.02, CRP (mg/L): 129.68±49.83 vs. 3.16±2.85], with statistically significant differences (all P < 0.05). Pearson correlation analysis showed that the expression of antimicrobial peptide LL-37 was positively correlated with PCT and CRP levels (r1 = 0.835, r2 = 0.932, both P < 0.01). ROC curve analysis showed that the area under ROC curve (AUC) of LL-37, PCT and CRP for early diagnosis of sepsis was 0.885, 0.963 and 0.983, respectively, and the AUC of combined diagnosis of the three parameters was as high as 0.994, indicating that the value of combined diagnosis of sepsis was greater than that of single diagnosis; when the combined prediction probability of the three parameters was 0.92, the sensitivity was 97.5%, and the specificity was 95.0%.@*Conclusion@#Antibacterial peptide LL-37 has certain clinical value in early diagnosis of patients with sepsis, which can be used as early routine monitoring indicators for patients with early sepsis when combined with PCT and CRP.

Evaluation value of human antibacterial peptide LL-37 on the prognosis of elderly patients with sepsis / 中华危重病急救医学

Objective To evaluate the prognostic value of human antibacterial peptide LL-37 in elderly patients with sepsis. Methods Elderly sepsis patients over 65-year-old satisfied the diagnostic criteria for sepsis and septic shock admitted to intensive care unit of East Hospital of Tongji University from January 2016 to December 2017 were enrolled (elderly sepsis group). Aged community-acquired pneumonia (CAP) patients hospitalized during the same period were enrolled as a control group for pneumonia, and the aged health check-ups served as a healthy control group during the same period. The peripheral blood LL-37 levels of all patients on the 1st, 3rd, 7th day of admission and the results on the day of physical examination in the healthy control group and on the day of admission in aged CAP group were recorded. C-reactive protein (CRP), arterial blood lactate (Lac), procalcitonin (PCT) were monitored, and acute physiology and chronic health evaluation Ⅱ (APACHEⅡ) and sequential organ failure assessment (SOFA) scores were calculated based on the worst values within 24 hours. The correlation between LL-37 and various indicators was analyzed by Spearman method. According to the 28-day clinical outcome, the elderly patients with sepsis were divided into survival group and non-survival group. The differences in all parameters between the two groups were compared. The statistically significant indicators were analyzed by receiver operating characteristic (ROC) curve, and the predictive value of each indicator for prognosis was evaluated. Results ① A total of 113 elderly patients with sepsis were enrolled in the final analysis, including 67 patients in sepsis group and 46 patients in septic shock group. Thirty-two patients were enrolled as healthy controls and 31 elderly patients with CAP as elderly pneumonia group. The PCT, CRP, Lac, APACHEⅡ and SOFA scores of the patients in the three groups were higher than those of the healthy control group, and they were gradually increased with the severity of infection. There was no significant difference in gender or age among the groups. Compared with the healthy control group, the other three groups had higher LL-37 level after admission, the LL-37 levels in the sepsis group and the septic shock group were decreased with the prolongation of the hospitalization time, and they were lower than the pneumonia group at 7 days after admission [LL-37 (μg/L): 1 403.9±501.9, 1 517.1±676.4 vs. 1 608.4±816.2, both P > 0.05]. It was shown by correlation analysis that the LL-37 level in peripheral blood of elderly patients with sepsis was significantly negatively correlated with APACHEⅡ score (r = -0.329, P = 0.007) and SOFA score (r = -0.344, P = 0.005), but no significant correlation with Lac was found (r = -0.128, P = 0.311). ② The 28-day survival analysis revealed that of the 113 elderly patients with sepsis, 54 (47.8%) survived at 28 days and 59 (52.2%) died. There was no significant difference in gender, age, PCT or CRP levels at 1 day after admission between the two groups. The 1-day Lac, APACHEⅡ and SOFA scores of the patients in the non-survival group were significantly higher than those in the survival group, they were gradually increased with the prolongation of the hospitalization time, and they were significantly higher than those in the survival group at 7 days after admission [Lac (mmol/L): 2.4 (1.4, 4.4) vs. 1.0 (0.8, 1.7), APACHEⅡ score: 21.77±5.85 vs. 13.74±4.99, SOFA score: 9.62±4.78 vs. 3.18±2.71, all P < 0.01]. With the prolongation of admission, there was no significant change in LL-37 level of peripheral blood in the survival group. The LL-37 level in the non-survival group showed a downward tendency, and it was significantly lower than that in the survival group at 7 days after admission (μg/L: 1 277.8±642.6 vs. 1 620.6±461.6, P < 0.05). It was shown by ROC curve analysis that the LL-37 in peripheral blood, Lac, APACHEⅡ score and SOFA score at 7-day of admission of elderly patients with sepsis had predictive value for prognosis, and LL-37 had the best predicted effect for 28-day death, the area under the ROC curve (AUC) of LL-37 was 0.670, 95% confidence interval (95%CI) = 0.513-0.757, when the optimal cut-off value was 1 283.0 μg/L, the sensitivity was 75.7%, and the specificity was 61.5%. Conclusions The expression of LL-37 increased in the early course of the disease in elderly patients with sepsis. However, as the disease progressed and worsened, the level of LL-37 had a decline tendency and was associated with death. The dynamic monitoring of LL-37 combined with APACHEⅡ and SOFA scores had clinical guidance value in predicting the prognosis of sepsis in the elderly.

Purification, identification and characterization of an anti-microbial hexapeptide from Sus scrofa lysozyme / 生物工程学报

Sus scrofa lysozyme (SSL) was digested by different proteases to find peptides with enhanced antibacterial activity against gram-negative bacteria. Hydrolysate with the highest anti-bacterial activity was loaded onto a gel filtration chromatography column followed by a reversed-phase one. The obtained substance was identified by liquid chromatography-mass spectrometry, synthesized to test its antibacterial spectrum and analyzed for bioinformatics. The hydrolysate of trypsin showed the highest antibacterial activity. By purification and identification, the functional peptide with sequence of A-W-V-A-W-K was obtained. The peptide was synthesized and proved to retain partial function of SSL and had activity against gram-negative bacteria. By bioinformatics analysis, the peptide was found to locate in a helix-loop-helix structure, suggesting that the peptide may kill cells by penetrating cell membrane and cause the outflow of cell contents. The discovery of the peptide could lay the foundation for improving the antibacterial activity of SSL.

Antibacterial study on human umbilical cord mesenchymal stem cells supernatant combined with amoxicillin on Staphylococcus aureus / 中国修复重建外科杂志

Objective: To study the antibacterial activity of human umbilical cord mesenchymal stem cells (hUCMSCs) culture supernatant and amoxicillin on Staphylococcus aureus isolated from burn wounds.

The antifungal study of antibacterial peptide MUC7 combined with Bifidobacterium in vitro / 重庆医学

Objective To investigate the cooperative antifungal effect of antibacterial peptide MUC7 combined with Bifidobacte‐ria in vitro .Methods The antifungal effect was observed and measured by viable count and the Oxford cup method .Results Two methods exhibited more potent antifungal effect on Candida albicans ,Candida albicans ,Candida krusei and Candida parapsilosis in MUC7 combined with Bifidobacteria group .The colonies′numbers in MUC7 combined with Bifidobacteria group were 2 .00 ± 1 .13 , 2 .00 ± 1 .42 ,5 .00 ± 2 .03 ,2 .00 ± 1 .39 respectively by viable counting ,which was lower than thoes in the saline group and Bifidobacterium group (P<0 .01) ,these two groups were significant lower than those in MUC7 group (P<0 .05);the inhibition zone in MUC7 combined with Bifidobacteria group were (29 .00 ± 2 .17) ,(31 .00 ± 3 .25) ,(29 .00 ± 2 .89) ,(30 .00 ± 3 .36)mm de‐tected by the Oxford cup method ,which showed a significantly difference with the saline group ,Bifidobacterium group and MUC7 group(P< 0 .05) .Conclusion Antibacterial peptide MUC7 combined with Bifidobacterium exhibits good antifungal effect which may provide a foundation for the further research on a new generation of antifungal Bifidobacterium preparation .

Antibacterial peptide activity and vitamin D level / 国际儿科学杂志

Vitamin D,an immune regulator,plays an important role in innate immune function of antibacterial peptide.Vitamin D takes part in the innate immune function via toll-like receptor in response to pathogen,then release antibacterial peptide.This study describes the antibacterial peptide constitution and the functions,effection of activeted Vitamin D in innate immune function of antibacterial peptide.

Antibacterial Peptides of The Ovine Reproductive Tract / 生物化学与生物物理进展

The female sheep reproductive tracts were freshly collected from a local meat processing plant and used as experimental materials. Two antibacterial peptides were isolated and characterized from female sheep reproductive tracts by two consecutive chromatographic steps. The peptide isolation procedures included acetic acid extraction, dialyzed, gel filtration chromatography on Sephadex G-50, and reverse phase high-performance liquid chromatography (RP-HPLC). Their molecular mass were 4 820.47 u and 4 012.5 u, respectively, analyzed by MALDI-TOF-MS. The partial N-terminal amino acid sequences of two peptides were determined as AYVLDEPKP and YDSGA, respectively, by Edman degradation. The antimicrobial activity was tested during each purification step by the radial diffusion plate assay and broth microdilution method. These two peptides showed good antimicrobial activities against reference strains of G~+(S. Aureus ATCC2592 and Streptococcu ATCC55121), G~-(E. Coli ATCC25922) and fungi(C. Albicans ATCC2002). The peptides did not show active hemolytic activity against rabbit blood red cells and had no significant effects on human blood coagulation system. The discovery of antibacterial peptides in sheep reproductive system reveals that antibacterial peptides may play a role in innate immunity against microorganisms in a wide range of animal species.

Cloning of the antibacterial peptide cecropin gene of Musca domestica larvae and its fusion expression in Escherichia coli / 中国人兽共患病学报

In the present study, the total RNA was extracted from three instar larvae of Musca domestica, the cDNA sequence encoding the ORF of cecropins was amplified by RT-PCR, and the target fragment was further sequenced after being cloned into T vector pUCm-T. Then, the cDNA sequence of the mature cecropins was amplified by PCR with recombinant plasmid pUCm-T/cecropin as template, the N-terminal rare codon GGA of E. coli was changed to the favorable codon GGC,and a Asn codon AAC was added in front of the stop coden TAA in the C- terminus. This mutant gene designated as mCecropin was then ligated with the fusion expression vector pGEX-4T-1. After restriction analysis and DNA sequencing, the positive recombinant plasmid pGEX-4T-1/mCecropin was transformed to different strains of E. coli cells and the fusion protein was expressed after IPTG induction. The fusion protein was assayed by SDS-PAGE and the E. coli BL21(DE3) cell was chosen as the host cell for the expression of the fusion protein. The expressed fusion protein GST-mCecropin was purified by GSTrap affinity coloum and the GST marker was then cleaved by thrombin. In this way, the fusion protein mCecropin with antibacterial activity was obtained after purification with HiTrap benzamidine column.

Antibacterial effect of the antibacterial peptide from housefly larvae on Enterobacter cloacae infected wound in mice / 重庆医科大学学报

Objective:To investigate the antibacterial effects of the antibacterial substances on Enterobacter cloacae infection of wound in mice.Methods:Antibacterial substances of the larvae of housefly were induced by ultrasonic treatment,and its antibacterial activity was investigated with inhibition experiment in vitro.Thirty ICR mice were enrolled in the study,and the Enterobacter cloacae infection model was re-produced by excision of the full layer of dorsal skin with anarea of 1 cm?1 cm.Then they were randomly divided into group C(control,n=10,with wet compress of isotonic saline),group M(with hydropathic compress of 100 g/L mafenide)and group A(with wet compress of 0.1 g/L antibacterial peptide).The changes of white blood cell counts in each group were determined before and 3 days after injury.Bacterial growth in muscular tissue of the wounds and the survival of the mice were observed at 3 days after injury.Results:The purified peptide was highly potent against Enterobacter cloacae in vitro.The number of leucocytes in each group was decreased after operation,with significantly less number in group C than in group M and A.Bacterial growth in muscle demonstrated a difference between treated groups and group C at 3 days [group M:(87?31)?102 CFU/g;group A:(99?32)?102 CFU/g;group C:(504?338)?103 CFU/g(]P

Characterization of an antibacterial peptide from indian cobra (Naja naja) venom

Due to the development of antibiotic resistance in microorganisms, antimicrobial peptides from natural sources have attracted attention in recent times. Several antimicrobial peptides have been isolated from a wide range of animal sources, particularly snake venoms. Naja naja venom showed antibacterial as well as direct and indirect hemolytic activities, and an antibacterial peptide was purified through gel permeation and ion exchange chromatography. Its molecular mass was 2491Da, which was determined using Matrix Assisted Laser Desorption/Ionization-Time-of-Flight (MALDI-TOF) mass spectrometry and the amino acids sequence of the N-terminus was DEQSTHGAYVWKL. The purified peptide showed potent antibacterial activity against Gram-negative and Gram-positive bacterial strains like Escherichia coli, Pseudomonas aeruginosa and Vibrio cholerae, and Staphylococcus aureus, Enterococcus faecalis, Streptococcus pneumoniae, Streptococcus pyogenes, Bacillus subtilis, respectively. The most potent activity was towards Gram-negative bacteria. Activity was retained at concentrations as low as 100µg/ml. Minimum inhibitory concentrations (MIC; in mg) of Naja Antibacterial Peptide (NAP) and known antibiotics against Gram-positive and Gram-negative bacteria were determined using microdilution susceptibility test in sterile 96-well microdilution plates. However, the peptide did not show direct or indirect hemolytic activity.(AU)

System of Intein-mediated PHB Purified Human Antimicrobial Peptide LL-37 / 中国生物工程杂志

The new intein-mediated PHB purify protein system is a high expression, automatic cutting, for purification, low-cost protein purification system,it is conducive to large-scale protein purification.Choose human antibacterial peptide LL-37 as the purification objects,which is poison to prokaryotic cell.We construct intein-mediated PHB purified human antimicrobial peptide LL-37 system through genetic engineering technology and use this system to purify LL-37. The results show that this system can highly express LL-37 fusion protein and purifiy the product as same size with expectations.

Expression of antibacterial peptide gloverin in vitro / 中国临床药理学与治疗学

AIM: To construct a recombinant vector containing gloverin and express it in vitro by Rapid Translation System(RTS500). METHODS: The gloverin cDNA was amplified by PCR and inserted into the prokaryotic expression vector pIVEX2.3. The recombinant product was identified by PCR and enzyme digestion. The positive reconstructed expression plasmid pIVEX2.3-G was expressed by RTS500 in vitro. The expressed protein was identified by SDS-PAGE and western blotting. RESULTS: Positive recombinant plasmid pIVEX2.3-G was successfully constructed. Target protein of 13.8 Kda with 6-his tag was detected by SDS-PAGE and western blotting. CONCLUSION: Gloverin polypeptide is successfully expressed in inactive E.coli in vitro.

In vitro effects of cecropin-like antibacterial peptide from Helicobacter pylori on gastric cancer cells and gastric epithelial cells / 中华消化杂志

Objective To observe the in vitro effects of cecropin like anti bacterial peptide (2 20) from Helicobacter pylori ( H.pylori ) on gastric epithelial cells and gastric cancer cells. Methods The inhibition zone assay was used to determine anti bacterial activity and lethal concentrations of H.pylori anti bacterial peptide (2 20) and cecropin B on E.coli K12D31 (standard strain). The cytotoxicities and IC 50 of the H.pylori anti bacterial peptide (2 20) and cecropin B on human gastric epithelial cells and on gastric cancer cell lines were measured by MTT colorimatric methods. Results In vitro, the lethal concentrations (LC) of H.pylori anti bacterial peptide (2 20) and cecropin B on E.coli K12D31 were 65 ?mol/L and 0.44 ?mol respectively. The killing effects of cecropin B were more prominent than those of H.pylori anti bacterial peptide (2 20). The synthetic peptide H.pylori anti bacterial peptide(2 20) and cecropin B showed lytic or toxic activity against the human gastric cancer cell line SGC 7901 in a concentration dependent manner. The H.pylori anti bacterial peptide (2 20) stimulates the gastric epithelial cell GES 1 proliferation at the concentration ranging from 50 ?mol/L to 200 ?mol/L. The cecropin B has no lytic or toxic activety against gastric epithelial cell GES 1 at the concentration ranging from 5 ?mol/L to 20 ?mol/L. The IC 50 of H.pylori anti bacterial peptide (2 20)were 630 ?mol/L for GES 1 cells and 500 ?mol/L for SGC 7901 cells. The IC 50 of cecropin B were 75 ?mol/L for GES 1 cells and 25 ?mol/L for SGC 7901 cells respectively.Conclusions The H.pylori anti bacterial peptide (2 20) has a lower anti bacterial activity than cecropin B and there is a concentration dependent cytotoxic effect on the gastric cancer cells. The cecropin like antibacterial peptide from H.pylori anti bacterial peptide (2 20) stimulates the gastric epithelial cell proliferation at lower concentration and thus may be expected to increase the risk of gastric cancer.

THE ANTIBACTERIAL PEPTIDE CM4 INHIBITS REGENERATION OF SACCHAROMYCES CEREVISIAE PROTOPLAST BY DAMAGING ON THE PLASMA MEMBRANES / 微生物学通报

The antibacterial peptide CM4 having potent antifungal activity on inhibitiong the cell wall regeneration of Saccharomyces cerevisiae protoplasts.When the peptide increased,the ratio of the regenerated colonies drop obviously.To study the antifungal mechanism of the antibacterial peptide,fluorescence\|labeled peptide mixted with the protoplast of yeast,then confocal laser scanning microscopy were performed.The results indicated that the peptides interactted with the protoplast membrane and damaged the structure of the membrane,then the permeation of protoplast changed.Finally the protoplasts with the peptide failed to regenerate the cell walls leading to killing the cell.