Search results for "Protein Sequencing"
showing 10 items of 17 documents
cDNA sequences of two arylphorin subunits of an insect biliprotein: phylogenetic differences and gene duplications during evolution of hexamerins-imp…
2016
Arylphorins represent a conserved class of hexameric ∼500 kDa insect hemolymph glycoproteins, rich in aromatic amino acids, which are produced in large quantities at the larval stage as reserves for metamorphosis and egg development. The recently isolated arylphorin from the moth Cerura vinula is unique in being complexed to a novel farnesylated bilin. Protein sequencing suggested the presence of two different ∼85 kDa subunits. Here, we report the complete coding sequences of two cDNAs encoding two arylphorins subunits with 67% identity and calculated physicochemical characteristics in agreement with the isolated holoprotein. Our phylogenetic analyses of the hexamerins revealed monophyletic…
Comparison of hemolytic activity of the intermediate subunit of Entamoeba histolytica and Entamoeba dispar lectins.
2017
Galactose and N-acetyl-D-galactosamine-inhibitable lectin of Entamoeba histolytica has roles in pathogenicity and induction of protective immunity in rodent models of amoebiasis. Recently, the intermediate subunit of the lectin, Igl1, of E. histolytica has been shown to have hemolytic activity. However, the corresponding lectin is also expressed in a non-virulent species, Entamoeba dispar, and another subunit, Igl2, is expressed in the protozoa. Therefore, in this study, we compared the activities of Igl1 and Igl2 subunits from E. histolytica and E. dispar using various regions of recombinant Igl proteins expressed in Escherichia coli. The recombinant E. dispar Igl proteins had comparable h…
Critical amino acids for the insecticidal activity of Vip3Af from Bacillus thuringiensis: Inference on structural aspects
2018
AbstractVip3 vegetative insecticidal proteins from Bacillus thuringiensis are an important tool for crop protection against caterpillar pests in IPM strategies. While there is wide consensus on their general mode of action, the details of their mode of action are not completely elucidated and their structure remains unknown. In this work the alanine scanning technique was performed on 558 out of the total of 788 amino acids of the Vip3Af1 protein. From the 558 residue substitutions, 19 impaired protein expression and other 19 substitutions severely compromised the insecticidal activity against Spodoptera frugiperda. The latter 19 substitutions mainly clustered in two regions of the protein …
Automated selection of homologs to track the evolutionary history of proteins
2018
Background The selection of distant homologs of a query protein under study is a usual and useful application of protein sequence databases. Such sets of homologs are often applied to investigate the function of a protein and the degree to which experimental results can be transferred from one organism to another. In particular, a variety of databases facilitates static browsing for orthologs. However, these resources have a limited power when identifying orthologs between taxonomically distant species. In addition, in some situations, for a given query protein, it is advantageous to compare the sets of orthologs from different specific organisms: this recursive step-wise search might give …
Characterization of Bacillus thuringiensis isolates by their insecticidal activity and their production of Cry and Vip3 proteins.
2018
WOS: 000449027600099 PubMed ID: 30383811 Bacillus thuringiensis (Bt) constitutes the active ingredient of many successful bioinsecticides used in agriculture. In the present study, the genetic diversity and toxicity of Bt isolates was investigated by characterization of native isolates originating from soil, fig leaves and fruits from a Turkish collection. Among a total of 80 Bt isolates, 18 of them were found carrying a vip3 gene (in 23% of total), which were further selected. Insecticidal activity of spore/crystal mixtures and their supernatants showed that some of the Bt isolates had significantly more toxicity against some lepidopteran species than the HD1 reference strain. Five isolate…
The SARS-CoV-2 envelope (E) protein has evolved towards membrane topology robustness.
2021
- Single-spanning SARS-CoV-2 envelope (E) protein topology is a major determinant of protein quaternary structure and function. - Charged residues distribution in E protein sequences from highly pathogenic human coronaviruses (i.e., SARS-CoV, MERS-CoV and SARS-CoV-2) stabilize Ntout-Ctin membrane topology. - E protein sequence could have evolved to ensure a more robust membrane topology from MERS-CoV to SARS-CoV and SARS-CoV-2.
Gene structure and hemocyanin isoform HtH2 from the mollusc Haliotis tuberculata indicate early and late intron hot spots.
2002
Abstract We have cloned and sequenced cDNAs coding for the complete primary structure of HtH2, the second hemocyanin isoform of the marine gastropod Haliotis tuberculata. The deduced protein sequence comprises 3399 amino acids, corresponding to a molecular mass of 392 kDa. It shares only 66% of structural identity with the previously analysed first isoform HtH1, and according to a molecular clock, the two isoforms of Haliotis hemocyanin separated ca. 320 million years ago. By genomic polymerase chain reaction and 5′ race, we have also sequenced the complete gene of HtH2 (18,598 bp), except of the 5′ region in front of the secreted protein. It encompasses 15 exons and 14 introns and shows se…
The metal binding abilities of Megathura crenulata metallothionein (McMT) in the frame of gastropoda MTs.
2011
Metallothioneins (MTs) are proteins that play a major role in metal homeostasis and/or detoxification in all kind of organisms. The MT gene/protein system of gastropod molluscs provides an invaluable model to study the diversification mechanisms that have enabled MTs to achieve metal-binding specificity through evolution. Most pulmonate gastropods, particularly terrestrial snails, harbor three paralogous isogenes encoding three MT isoforms with different metal binding preferences: the highly specific CdMT and CuMT isoforms, for cadmium and copper respectively, and the unspecific Cd/CuMT isoform. Megathura crenulata is a non-pulmonate gastropod in which only one MT isogene has so far been re…
Unstructural Biology of TRP Ion Channels: The Role of Intrinsically Disordered Regions in Channel Function and Regulation
2021
The first genuine high-resolution single particle cryo-electron microscopy structure of a membrane protein determined was a transient receptor potential (TRP) ion channel, TRPV1, in 2013. This methodical breakthrough opened up a whole new world for structural biology and ion channel aficionados alike. TRP channels capture the imagination due to the sheer endless number of tasks they carry out in all aspects of animal physiology. To date, structures of at least one representative member of each of the six mammalian TRP channel subfamilies as well as of a few non-mammalian families have been determined. These structures were instrumental for a better understanding of TRP channel function and …
Widespread selection for high and low secondary structure in coding sequences across all domains of life
2019
AbstractCodon composition, GC-content and local RNA secondary structures can have a profound effect on gene expression and mutations affecting these parameters, even though they do not alter the protein sequence, are not neutral in terms of selection. Although evidence exists that in some cases selection favors more stable RNA secondary structures, we currently lack a concrete idea of how many genes are affected within a species, and if this is a universal phenomenon in nature.We searched for signs of structural selection in a global manner, analyzing a set of one million coding sequences from 73 species representing all domains of life, as well as viruses, by means of our newly developed s…