Shima Fooladband; parinaz ghadam; mahboubeh zarrabi
Abstract
Nano protein structures can be formed by the intrinsic ability of molecular self-assembly or via intermediates which improve their assembly. Hydrophobicity is the most important factor among the other intrinsic self-assembly factors and the other intermediates such as glutaraldehyde may lead to protein-assembly ...
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Nano protein structures can be formed by the intrinsic ability of molecular self-assembly or via intermediates which improve their assembly. Hydrophobicity is the most important factor among the other intrinsic self-assembly factors and the other intermediates such as glutaraldehyde may lead to protein-assembly and nanoparticles formation. In this study, Aggrescan 3D software was employed to investigate protein self-assembly properties. Peroxidase enzyme was selected to form protein nanoparticle, and glutaraldehyde changed it to a nano enzyme.FESEM and DLS analysis represented that the average size of nano enzyme is about 500 nanometers. Comparing biochemical properties of peroxidase enzyme before and after changing into nano, showed that the activity of nano enzyme at 20°C, pH7 has decreased as compared to the monomeric enzyme. Based on homology, the PDB structure of two peroxidase enzyme was identified. Then, the connection between glutaraldehyde and two peroxidase enzymes was detected. Enzyme residues with hydrogen binding connections to glutaraldehyde were also detected by using LigPlot software and the residues in active side of enzyme were determined by COACH server. Glutaraldehyde is connected to residues in active siteof the enzyme. Molecular dynamic Simulation was performed in the time duration of 5 nanoseconds and 30°C and it showed that monomer enzyme and nano enzyme are both stable in this time duration and temperature.
Mahboubeh Zarrabi; Elmira Naghdi
Abstract
Abstract Cyclotides are small disulfide rich peptides isolated from plants. Cyclotides have a range of biological activities including anti-HIV, insecticidal, anti-tumor and anti-microbial. Because of the ever-increasing number of drug resistant bacteria, healthcare worldwide is facing a serious challenge ...
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Abstract Cyclotides are small disulfide rich peptides isolated from plants. Cyclotides have a range of biological activities including anti-HIV, insecticidal, anti-tumor and anti-microbial. Because of the ever-increasing number of drug resistant bacteria, healthcare worldwide is facing a serious challenge and there is an urgent need for novel compounds to treat disease. Cyclotides have high potential to become the next generation of bio-active compounds. In this study, to evaluate the antimicrobial effect of cyclotides isolated from the Iranian violet we put cycloviolacin O2 near the bacterial model membrane and molecular dynamics simulations were performed for 200 nanoseconds. analysis show that cycloviolacin O2 adsorbs onto the membrane and it seems that hydrogen bonds have an important role in peptide adsorption onto the membrane. Over the simulation times, peptide remaining on the membrane surface and doesn't Penetrate into it, While the presence of peptide in the membrane surface increases irregularity of hydrocarbon chains.
Mohamad reza Masoumian; Zargham Sepehri zadeh; Rouha Kasra kermanshahi
Abstract
The aim of the present study was extraction and purification of cyclotides from Iranian Viola odorata and examination of their antimicrobial effects against Gram-positive S. aureus PTCC 1431. In the current study, the cyclotide was extracted and purified by fractionation method using SPE-C18 column. ...
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The aim of the present study was extraction and purification of cyclotides from Iranian Viola odorata and examination of their antimicrobial effects against Gram-positive S. aureus PTCC 1431. In the current study, the cyclotide was extracted and purified by fractionation method using SPE-C18 column. Determination of cyclotide purification degree and molecular weight was done by RP-HPLC and tricine SDS-PAGE methods, respectively. Antimicrobial effects of these peptides were studied by radial diffusion assays (RDAs). The results showed that antimicrobial effects of cyclotides were similar to vancomycin and amikacin. It seems that future studies might reveal and propose the use of these cyclotides in treatment of staphylococcal infections
