15 research outputs found
A nontoxic polypeptide oligomer with a fungicide potency under agricultural conditions which is equal or greater than that of their chemical counterparts
Research ArticleThere are literally hundreds of polypeptides described in the literature which exhibit fungicide
activity. Tens of them have had attempted protection by patent applications but none,
as far as we are aware, have found application under real agricultural conditions. The reasons
behind may be multiple where the sensitivity to the Sun UV radiation can come in first
place. Here we describe a multifunctional glyco-oligomer with 210 kDa which is mainly composed
by a 20 kDa polypeptide termed Blad that has been previously shown to be a stable
intermediary product of ÎČ-conglutin catabolism. This oligomer accumulates exclusively in
the cotyledons of Lupinus species, between days 4 and 12 after the onset of germination.
Blad-oligomer reveals a plethora of biochemical properties, like lectin and catalytic activities,
which are not unusual per si, but are remarkable when found to coexist in the same protein
molecule. With this vast range of chemical characteristics, antifungal activity arises
almost as a natural consequence. The biological significance and potential technological
applications of Blad-oligomer as a plant fungicide to agriculture, its uniqueness stems from
being of polypeptidic in nature, and with efficacies which are either equal or greater than the
top fungicides currently in the market are addressedinfo:eu-repo/semantics/publishedVersio
Computer aided identification of a Hevein-like antimicrobial peptide of bell pepper leaves for biotechnological use
Genes and evolution of two-domain toxins from lynx spider venom
AbstractSpiderines are comparatively long polypeptide toxins (âŒ110 residues) from lynx spiders (genus Oxyopes). They are built of an N-terminal linear cationic domain (âŒ40 residues) and a C-terminal knottin domain (âŒ60 residues). The linear domain empowers spiderines with strong cytolytic activity. In the present work we report 16 novel spiderine sequences from Oxyopes takobius and Oxyopes lineatus classified into two subfamilies. Strikingly, negative selection acts on both linear and knottin domains. Genes encoding Oxyopes two-domain toxins were sequenced and found to be intronless. We further discuss a possible scenario of lynx spider modular toxin evolution
WHEAT ANTIMICROBIAL PEPTIDES
Antimicrobial peptides (AMPs) are low-molecular-weight defense polypeptides, produced in all living organisms either constitutively or upon perception of signals from pathogenic microorganisms. They are important components of the immune system in both animals and plants. AMPs differ in structure and mode of action. Most of them belong to cysteine-rich peptides; their molecules contain even numbers of cysteine residues involved in the formation of disulphide bonds, which stabilize the peptide structure. A number of families of plant AMPs have been isolated on the base of amino acid sequence similarity and 3D structure. Plant AMP genes can be used in the engineering of pest resistance in crops and development of novel antibiotics and antimycotics. We provide a concise review of properties and gene structures of major AMP families discovered by the authors in Triticum kiharae seeds, including glycine-rich peptides, defensins, hevein-like peptides and the so-called 4-Cys peptides
Enteroviruses Manipulate the Unfolded Protein Response through Multifaceted Deregulation of the Ire1-Xbp1 Pathway
Many viruses are known to trigger endoplasmic reticulum (ER) stress in host cells, which in turn can develop a protective unfolded protein response (UPR). Depending on the conditions, the UPR may lead to either cell survival or programmed cell death. One of three UPR branches involves the upregulation of Xbp1 transcription factor caused by the unconventional cytoplasmic splicing of its mRNA. This process is accomplished by the phosphorylated form of the endoribonuclease/protein kinase Ire1/ERN1. Here, we show that the phosphorylation of Ire1 is up-regulated in HeLa cells early in enterovirus infection but down-regulated at later stages. We also find that Ire1 is cleaved in poliovirus- and coxsackievirus-infected HeLa cells 4–6 h after infection. We further show that the Ire1-mediated Xbp1 mRNA splicing is repressed in infected cells in a time-dependent manner. Thus, our results demonstrate the ability of enteroviruses to actively modulate the Ire1-Xbp1 host defensive pathway by inducing phosphorylation and proteolytic cleavage of the ER stress sensor Ire1, as well as down-regulating its splicing activity. Inactivation of Ire1 could be a novel mode of the UPR manipulation employed by viruses to modify the ER stress response in the infected cells