RESUMO
In the present study, the complete mitogenome of Cephaloscyllium fasciatum has been sequenced and assembled. The complete mitochondrial genome is 16,509 bp in length and contains 37 mitochondrial genes and a control region as other fishes. The nucleotide composition of C. fasciatum mitogenome showed an anti-G bias and an excess of AT content. Furthermore, maximum-likelihood phylogenetic tree was constructed based on 13 protein-coding genes of C. fasciatum and other 15 sharks. This work will provide molecular data for studies on phylogeny and evolution in the family Scyliorhinidae.
RESUMO
This study reports the complete mitochondrial genome of the Capsaloides cristatus (Monogenea: Capsalidae) collected from the gill lamella of Istiophorus platypterus. The total length of the mitogenome was 13,948 bp, containing 12 typical platyhelminthic protein-coding genes, 22 tRNA genes, 2 rRNA genes and a putative non-coding region, with the atp8 gene being absent. The total A + T content was 65.99%, which was significantly higher than that of the C + G content (34.01%). There were two kinds of start codons (ATG and GTG) and three kinds of terminated codons (TAA, TAG and TGA) in the 12 protein-coding genes. Phylogentic analysis revealed close relationships among the genera Capsaloides, Capsala, Benedenia and Neobenedenia with high bootstrap value supported. This study will provide useful molecular data for a better understanding of the species identification and phylogenetic position of C. cristatus.
RESUMO
Metal ions play a critical role in human islet amyloid polypeptide (hIAPP) aggregation, which is believed to be closely associated with ß-cell death in type II diabetes. In this work, the effect of Al3+ on the aggregation of hIAPP (11-28) was studied by several different experimental approaches. Atomic force microscopy measurements showed that Al3+ could remarkably inhibit hIAPP(11-28) fibrillogenesis, while Zn2+ had a slight promotion effect on peptide aggregation, which was also confirmed by Thioflavin T fluorescence observation. Furthermore, X-ray photoelectron spectroscopy measurement indicated that Al ions might form chemical bonds with neighboring atoms and destroy the secondary structures of the protein. Our studies could deepen the understanding of the role of metal ions in the aggregation of amyloid peptides.
Assuntos
Alumínio/farmacologia , Polipeptídeo Amiloide das Ilhotas Pancreáticas/química , Fragmentos de Peptídeos/química , Agregados Proteicos/efeitos dos fármacos , Agregação Patológica de Proteínas , Sequência de Aminoácidos , Amiloide/química , Humanos , Concentração de Íons de Hidrogênio , Íons/farmacologia , Polipeptídeo Amiloide das Ilhotas Pancreáticas/genética , Microscopia de Força Atômica , Fragmentos de Peptídeos/genética , Espectroscopia Fotoeletrônica , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Zinco/farmacologiaRESUMO
A structure of hexadecyl trimethyl ammonium bromide (CTAB) micelle-assisted reduced graphene oxide-Ag nanoparticle (rGO-AgNP) hybrids is designed and fabricated for SERS detection of nonpolar polycyclic aromatic hydrocarbons (PAHs), in which CTAB micelles act as the host material to capture PAH molecules. This method provides stable aqueous suspensions of functionalized graphene with an alkyl chain, since the rGO-AgNP hybrids do not need to be pre-modified by CTAB. The result shows that the CTAB-assisted rGO-AgNP substrate has excellent SERS performance toward PAHs and ideal stability under continuous laser radiation. With further optimization, the detection limits of pyrene and perylene were 10(-6) M and 10(-7) M, respectively. Two different PAH molecules could be detected simultaneously by their characteristic peaks.