ABSTRACT
<p><b>OBJECTIVE</b>To investigate the flexibility and mobility of the Bacillus thuringiensis toxin Cry1Aa.</p><p><b>METHODS</b>The graph theory-based program Constraint Network Analysis and normal mode-based program NMsim were used to analyze the global and local flexibility indices as well as the fluctuation of individual residues in detail.</p><p><b>RESULTS</b>The decrease in Cry1Aa network rigidity with the increase of temperature was evident. Two phase transition points in which the Cry1Aa structure lost rigidity during the thermal simulation were identified. Two rigid clusters were found in domains I and II. Weak spots were found in C-terminal domain III. Several flexible regions were found in all three domains; the largest residue fluctuation was present in the apical loop2 of domain II.</p><p><b>CONCLUSION</b>Although several flexible regions could be found in all the three domains, the most flexible regions were in the apical loops of domain II.</p>
Subject(s)
Bacillus thuringiensis , Bacterial Proteins , Chemistry , Genetics , Metabolism , Cluster Analysis , Computer Simulation , Endotoxins , Chemistry , Genetics , Metabolism , Entropy , Hemolysin Proteins , Chemistry , Genetics , Metabolism , Models, Structural , Mutation , Protein Conformation , Protein Unfolding , Software , TemperatureABSTRACT
Objective: To study the secondary metabolites of Eurotium cristatum from Fu Brick Tea and their biological activities. Methods: The compounds were isolated by various column chromatographies on normal phase silica gel, reversed silica gel, Sephadex LH-20, preparative TLC, and recrystallization. The structures were identified by the extensive analysis on their spectroscopic data. The inhibitory effects of compounds 1-9 against SF-268, MCF-7, and NCI-H460 cell lines were tested in vitro by SRB method. The inhibitory effects of compounds 2-9 on Staphyloccocus aureus, Escherichia coli, Salmonella enterica subsp. enterica, Shigella dysenteriae, and Proteus vulgaris were tested by MTT method. Results: Nine compounds were isolated from the extract of liquid fermentation broth of E. cristatum in Fu Brick Tea and identified as physcion (1), 1, 5-dihydroxy-3-methoxy-7-methyl-anthracene-9,10-dione (2), flavoglaucin (3), 2-(2', 3-epoxy-1', 3'-heptadienyl)-6-hydroxy-5-(3-methyl-2-butenyl) benzaldehyde (4), 2-(2', 3-epoxy-1', 3', 5'-heptatrienyl)-6-hydroxy-5-(3-methyl-2-butenyl) benzaldehyde (5), isodihydroauroglaucin (6), tyrosol (7), p-hydroxybenzoic acid (8), and orcinol (9). The results of the bioactivity test showed that compounds 3-6 displayed the good cytotoxic acitivities against the three tumor cell lines, and all the compounds exhibited the strong inhibitory activities against P. vulgaris except compounds 1 and 6. Besides, compound 9 also showed the significant inhibitory effects against S. aureus and E. coli. Conclusion: The benzaldehyde compounds are considered as the main metabolites of E. cristatum, compounds 7 and 9 are reported from the species of genus Eurotium Link: Fr. for the first time and compounds 2, 3, 5, 6, and 8 are firstly isolated from the fungus.
ABSTRACT
<p><b>OBJECTIVE</b>To observe the clinical efficiency of curettage combining circumcision on giant condyloma acuminata(CA) in male external genitalia, the relationship between recurrence and curettage depth, the possibility of HPV infection in PBMC after operation.</p><p><b>METHODS</b>Curettage combining circumcision was carried out on 50 cases with CA. The removed wart and wound surface tissues were examined under light microcope and for HPV-DNA detection by PCR. HPV-DNA was detected in PBMC during < or =1 and > or =2 weeks after operation.</p><p><b>RESULTS</b>(1) 46 cases were cured completely after one treating (once the cure rate is 92%), 4 cases twice(twice the cure rate is 8%); (2) The tissues were proved to be HPV-DNA positive by PCR amplification and CA relapse occurred; (3) HPV-DNA was detected in PBMC only within the week after curettage in the 19 cases.</p><p><b>CONCLUSIONS</b>(1) The clinical efficiency of curettage combining circumcision on giant condyloma acuminata in male external genitalia is sure; (2) Cure rate and relapse rate are related with curettage depth; (3) Transient positive HPV-DNA in PBMC may be detected.</p>