Structural characterization of lipopeptide biomarkers isolated from Bacillus globigii

Spectra obtained using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry of Bacillus globigii (Bacillus subtilis niger) spores, vegetative cells and the culture supernatant show a cluster of biomarkers centered at a molecular mass of 1478 Da. Three biomarkers were isolated from the cell-free culture supernatant by solid-phase extraction and reversed-phase high-performance liquid chromatography, and characterized using various kinds of mass spectrometry. A Fourier transform mass spectrometer with a MALDI source was used to determine the monoisotopic protonated masses at 1463.8, 1477.8, and 1505.8 Da in order of elution. The mass differences of 14 and 28 Da suggest that they are homologous molecules. Alkaline hydrolysis of each species showed that it contained a lactone linkage. Strong acid hydrolysis released a fatty acid from an amide bond, consistent with a lipopeptide. A quadrupole time-of-flight instrument with a nanospray source was used to sequence the hydrolyzed forms of the three biomarkers. The cyclic lipopeptides were found to have amino acid sequences identical with those in fengycins and plipastatins, antimicrobial compounds with phospholipase inhibitor activity, previously identified in related species of Bacillus subtilis and Bacillus cereus.     

Can the Docking Experiments Select the Optimum Natural Bio-macromolecule for Doxorubicin Delivery?

Journal of Cluster Science - The effective entrapment of drugs into nanoparticles is one of the most important features during nanoparticles preparation. The percentage loaded drug into the...     

Absolute quantification of dystrophin protein in human muscle biopsies using parallel reaction monitoring (PRM)

The need for a reliable and accurate method to quantify dystrophin proteins in human skeletal muscle biopsies has become crucial in order to assess the efficacy of dystrophin replacement therapies in Duchenne muscular dystrophy as well as to gain insight into the relationship between dystrophin levels and disease severity in Becker's muscular dystrophy. Current methods to measure dystrophin such as western blot and immunofluorescence, while straightforward and simple, lack precision and sometimes specificity. Here, we standardized a targeted mass spectrometry method to determine the absolute amount of dystrophin in ng/mg of muscle using full‐length ¹³C6–Arg– and ¹³C6,¹⁵N2–Lys–labeled dystrophin and parallel reaction monitoring (PRM). The method was found to be reproducible with a limit of quantification as low as 30 pg of dystrophin protein per mg of total muscle proteins. The method was then tested to measure levels of dystrophin in muscle biopsies from a healthy donor and from Duchenne and Becker's muscular dystrophy patients.     

Macrocyclic [N<Subscript>5</Subscript>] transition metal complexes: synthesis,characterization and biological activities

Novel penta-azamacrocyclic 21-membered [N₅] ligand [L] and its transition metal complexes with Co(II), Ni(II), Cu(II), Ru(III) and Pd(II) have been isolated and characterized. The mode of bonding and overall geometry of the complexes have been inferred through IR, MS, UV–Vis, EPR, ¹H NMR spectral studies, molar conductivity, magnetic, thermal and microanalyses, On the basis of above studies, an octahedral geometry has been proposed for all complexes except Pd(II) chloride complex which adopt square planar geometry. The in vitro antitumor activity of the synthesized ligand and some selected complexes against human breast and human hepatocarcinoma cell lines (MCF-7) and (HePG2), respectively has been studied. The results show that the tested compounds are potent antitumor agents. Also the ligand and some selected complexes have been tested for their inhibitory effect on the growth of bacteria: Streptococcus pyogenes as Gram-positive bacteria and Escherichia coli as Gram-negative bacteria. The activity data show that most of the tested compounds exhibit remarkable antibacterial activity against these organisms.     

Legendre Curves and the Singularities of Ruled Surfaces Obtained by Using Rotation Minimizing Frame

Ukrainian Mathematical Journal - We represent Legendre curves in unit tangent bundle by using rotation minimizing vector fields. Ruled surfaces corresponding to these curves are specified. The...     

Complete sequences of small acid-soluble proteins from Bacillus globigii

Three abundant small acid-soluble proteins (SASPs) from spores of Bacillus globigii were sequenced using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry with post-source decay and nanoelectrospray collision-induced dissociation tandem mass spectrometry. The proteins were extracted from spores with 1 M HCl. Scanning electron micrographs of spores before and after acid extraction show that the spores retain their overall structure but have a shriveled texture following the acid treatment. Extracted SASPs were purified by high-performance liquid chromatography and molecular masses of the SASPs were identified at 7068 (SASP-1), 7332 (SASP-2), and 8889 (gamma-SASP). De novo peptide sequencing was used to determine the protein sequences. The correct ordering of peptide sequences was aided by mapping overlapping enzymatic digests and by comparison with homologous SASPs from Bacillus stearothermophilus. B. globigii is used in many field tests as a surrogate for B. anthracis. Thus complete SASP sequences from B. globigii will facilitate the development of methods for rapid identification of bacteria based on mass spectrometry and the examination of taxonomic relationships between Bacillus species.