4,390 research outputs found
Delving into Vertebrate Serpins for Understanding their Evolution
The superfamily of serine proteinase inhibitors (serpins) is involved in an array of fundamental biological processes such as blood coagulation, cell differentiation, cell migration, complement activation, embryo implantation, fibrinolysis, angiogenesis, and inflammation, and tumor suppression. Vertebrate serpins can be conveniently classified into six sub-groups, based on three independent biological features - genomic organization, diagnostic amino acid sites and rare indels. The present vertebrate serpins are derived from an original serpin most probably by intron insertion and we are trying to reconstruct the phylogeny of vertebrate serpin and looking for the reconstruction of original vertebrate gene(s). We started with fish genomes and characterized fish serpins and assigned orthology with respect to human serpins. Most fish serpins are characterised as stereotype vertebrate serpins with some interesting exceptions which suggest that either there are some fish-specific serpins or some fish serpins do not have human orthologs.

Presented at "BREW 2005":http://cmb.molgen.mpg.de/brew/program.html
Deciphering the phylogenetic history of neuroserpin orthologs across metazoans by analysis of synteny and rare genomic characters
The superfamily of serine proteinase inhibitors (serpins) is involved in wide arrays of fundamental biological processes such as blood coagulation, complement activation, fibrinolysis, angiogenesis, inflammation and tumor suppression. The average protein size of a serpin family member is 350-400 amino acids, but gene structure varies in terms of number and position of exons and introns. All known serpins can be grouped into 16 clades and 10 orphan sequences. Vertebrate serpins can be conveniently classified into six sub-groups, based on three independent biological features - genomic organization, diagnostic amino acid sites and rare indels.
The objective of this study was to elucidate the phylogenetic kinships of serpins involved in surveying the secretory pathway routes against uncontrolled proteolytic activity. Though phylogenetic classification of vertebrate serpins into six groups based on gene organisation is well established, the evolutionary roots beyond the fish/tetrapod split are unresolved. This study illustrates that the analysis of microsynteny and other rare characters can provide insight into the intricate family history of metazoan serpins. Rare genomic characters/changes (RGC) are used to decipher that orthologs of neuroserpin, a prominent representative of vertebrate group 3 serpin genes, exist in early diverging deuterostomes and probably also in cnidarians, indicating that the origin of a mammalian serpin can be traced back far in the history of eumetazoans.

X-ray Diffraction Analysis of Cu2+ Doped Zn1-xCuxFe2O4 Spinel Nanoparticles using Williamson-Hall Plot Method
The nanoparticles (NPs) of Zn1-xCuxFe2O4 (ZCFO) spinels with x = 0, 0.2, 0.4,
0.6 and 0.8 were synthesized by a sol-gel combustion method using acetate
precursor. The NPs of ZCFO were prepared by following calcination process at
600C for 8hrs. The synthesized NPs of ZCFO were characterized by X-ray
diffraction (XRD) analysis using Rietveld refinement. The Rietveld refinement
of the XRD patterns revealed that the ZCFO spinels crystallize into single
diamond cubic structure with Fd-3m space group. The lattice constant and unit
cell volume for ZCFO NPs shrink with enhancing doping concentration of Cu2+
ion. The crystalline growth in the NPs of ZCFO was examined by peak broadening
present in the XRD pattern. The Williamson-Hall (W-H) plot method were used to
study the individual involvements of crystallite sizes and lattice strain on
the peak broadening of the NPs of ZCFO spinels. Whereas, particle size of the
ZCFO sample with x = 0.40 was estimated by high-resolution scanning electron
microscopy micrograph
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