Purothionin analogues from barley flour

Redman, D. G.; Fisher, N.

doi:10.1002/jsfa.2740200715

Cited by 63 publications

(37 citation statements)

References 9 publications

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“…The nsLTPs from wheat and maize seeds were kindly provided by Dr. Didier Marion (Institut National de Ia Recherche Agronomique, Nantes, France), and the nsLTP from radish was purified as described by Terras et al (1992a). Ac-AMP1 was isolated from amaranth seeds as described by Broekaert et al (1992), and P-purothionin was purified from wheat flour by the method of Redman and Fisher (1969).…”

Section: Methodsmentioning

confidence: 99%

A Potent Antimicrobial Protein from Onion Seeds Showing Sequence Homology to Plant Lipid Transfer Proteins

et al. 1995

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An antimicrobial protein of about 1 O kD, called AceAMPl, was isolated from onion (Allium cepa L.) seeds. Based on the nearcomplete amino acid sequence of this protein, oligonucleotides were designed for polymerase chain reaction-based cloning of the corresponding cDNA. l h e mature protein is homologous t o plant nonspecific lipid transfer proteins (nsLTPs), but it shares only 76% of the residues that are conserved among all known plant nsLTPs and is unusually rich in arginine. AceAMP1 inhibits all 12 tested plant pathogenic fungi at concentrations below 10 pg mL-'. Its antifungal activity is either not at all or is weakly affected by the presence of different cations at concentrations approximating physiological ionic strength conditions. AceAMP1 is also active on two Cram-positive bacteria but is apparently not toxic for Cram-negative bacteria and cultured human cells. In contrast t o nsLTPs such as those isolated from radish or maize seeds, AceAMPI was unable t o transfer phospholipids from liposomes to mitochondria. On the other hand, lipid transfer proteins from wheat and maize seeds showed little or no antimicrobial activity, whereas the radish lipid transfer protein displayed antifungal activity only in media with low cation concentrations. l h e relevance of these findings with regard to the function of nsLTPs is discussed.Although plant seeds are usually sown on a substrate that is extremely rich in microorganisms, infection of seeds or seedling tissues normally occurs at relatively low frequency. It is believed that seed proteins that exhibit antimicrobial activity may participate in the protection of seeds against potential microbial invaders. Different types of antimicrobial proteins have been purified from plant seeds '

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Section: Methodsmentioning

confidence: 99%

A Potent Antimicrobial Protein from Onion Seeds Showing Sequence Homology to Plant Lipid Transfer Proteins

et al. 1995

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“…Based on the multiple-alignment criteria of Feng & Doolittle (1987), all the available thionin amino acid sequences were classified into four well-defined structural types (I to IV, García-Olmedo et al, 1989, two of which were present in the cereals wheat and barley. Type I corresponds to the original purothionins from wheat flour (Balls et al, 1942a,b), which were later characterized in barley endosperm (Redman & Fisher, 1969), and type II is represented by thionins first isolated from the leaves of the parasitic plant Pyrularía púbera (Vernon et al, 1985) and then identified in those of barley (Bohlman & Apel, 1987;Gausing, 1987). Types III and IV respectively include the viscotoxins from mistletoes and the crambins from the Abyssinian cabbage (see García-Olmedo et al, 1990).…”

Section: Introductionmentioning

confidence: 99%

Extreme divergence of a novel wheat thionin generated by a mutational burst specifically affecting the mature protein domain of the precursor

Castagnaro¹,

Maraña²,

Carbonero³

et al. 1992

Journal of Molecular Biology

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A new type of neutral thionin (type V), specifically expressed in developing wheat endosperm, has been found to be encoded by a set of single-copy genes located in the long arms of chromosomes 1A, IB and ID, within less than 10,000 base-pairs of those corresponding to the highly basic type-I thionins. Divergence between types I and V has occurred through a process of accelerated evolution that has affected the amino acid sequence of the mature thionin but not the precursor domains corresponding to the N-terminal signal peptide and the long C-terminal acidic peptide. This process in volved a deletion and a non-synonymous nucleotide substitution rate equal to the synonymous rate in the thionin sequence.

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“…Thionins were first identified as a group of low molecular weight proteins in the organic solvent-extractable fraction of wheat and barley flour (1,2). The purified proteins were subsequently found to kill microorganisms (3).…”

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confidence: 99%

The Cytotoxic Plant Protein, β-Purothionin, Forms Ion Channels in Lipid Membranes

Hughes¹,

Dennis²,

Whitecross³

et al. 2000

Journal of Biological Chemistry

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Thionins are small cysteine-containing, amphipathic plant proteins found in seeds and vegetative tissues of a number of plant genera. Many of them have been shown to be toxic to microorganisms such as fungi, yeast, and bacteria and also to mammalian cells. It has been suggested that thionins are present in seeds to protect them, and the germinating seedling, from attack by phytopathogenic microorganisms, but the mechanism by which they kill cells remains unclear. Using electrophysiological measurements, we have shown that ␤-purothionin from wheat flour can form cation-selective ion channels in artificial lipid bilayer membranes and in the plasmalemma of rat hippocampal neurons. We suggest that the generalized toxicity of thionins is due to their ability to generate ion channels in cell membranes, resulting in the dissipation of ion concentration gradients essential for the maintenance of cellular homeostasis.

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Purothionin analogues from barley flour

Cited by 63 publications

References 9 publications

A Potent Antimicrobial Protein from Onion Seeds Showing Sequence Homology to Plant Lipid Transfer Proteins

A Potent Antimicrobial Protein from Onion Seeds Showing Sequence Homology to Plant Lipid Transfer Proteins

Extreme divergence of a novel wheat thionin generated by a mutational burst specifically affecting the mature protein domain of the precursor

The Cytotoxic Plant Protein, β-Purothionin, Forms Ion Channels in Lipid Membranes

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