Journal ArticleDOI
Toxic Proteins Inhibiting Protein Synthesis
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TLDR
Proteins which destroy various organisms are widely distributed in nature and very small amounts of these toxic proteins, often termed "toxins" or "protein toxins", exert a pronounced effect and the lethal dose is often a few ~zg per kg body weight, or even less.Abstract:
Proteins which destroy various organisms are widely distributed in nature. Some of these proteins exert their toxic effect by inhibiting protein synthesis in a specific manner. Thus, Colicin E 3 kills susceptible bacteria by inhibiting ribosome function. It does this by splitting off a small fragment from the t6S ribosomal RNA thus inactivating the 30S ribosomal subunit. Diphtheria toxin inhibits protein synthesis in eukaryotes by inactivating peptidyl-transferase II; this enzyme is necessary for the elongation of peptide chains on the ribosomes. Two toxic proteins from plants, abrin and ricin, also apparently interfere with some process necessary for the elongation of already initiated peptide chains. The possible physiological significance of the toxic proteins is discussed. There are in bacteria, as well as in plants and animals, proteins which have a highly toxic effect upon other organisms. Very small amounts of these toxic proteins, often termed "toxins" or "protein toxins", exert a pronounced effect and the lethal dose is often a few ~zg per kg body weight, or even less. Some cells and organs are highly sensitive to the action of a particular toxic protein, whereas others are virtually unaffected. Although their mechanism of action at the molecular level is largely unknown, it has recently become clear that some toxic proteins act by inhibiting protein synthesis.read more
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Book ChapterDOI
The interactions of lectins with animal cell surfaces.
TL;DR: This chapter discusses the interactions of lectins with animal cell surfaces, which have proven to be quite useful for clinical blood typing and structural studies of blood group substances, in analysis of the surface structure of normal and tumor cells, and so on.
Journal ArticleDOI
Characterization of two plant lectins from Ricinus communis and their quantitative interaction with a murine lymphoma.
Journal ArticleDOI
Different biological properties of the two constituent peptide chains of ricin, a toxic protein inhibiting protein synthesis.
Sjur Olsnes,Alexander Pihl +1 more
Journal ArticleDOI
Mechanism of action of the toxic lectins abrin and ricin
TL;DR: The mechanism of action of the plant toxins abrin and ricin is described, which inhibit protein synthesis probably by inactivating the 60S ribosomal subunits, interfering with chain elongation.
References
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Journal ArticleDOI
Diphtheria Toxin-dependent Adenosine Diphosphate Ribosylation of Aminoacyl Transferase II and Inhibition of Protein Synthesis
TL;DR: In the presence of diphtheria toxin, the adenosine diphosphate ribose portion of nicotinamide adenine dinucleotide was transferred to aminoacyl transferase II obtained from rat liver, which resulted in a concurrent inactivation of this particular enzyme.
Journal ArticleDOI
Structure and Activity of Diphtheria Toxin I. THIOL-DEPENDENT DISSOCIATION OF A FRACTION OF TOXIN INTO ENZYMICALLY ACTIVE AND INACTIVE FRAGMENTS
Robert J. Collier,Judith Kandel +1 more
TL;DR: It is shown that intact toxin is a precursor of nicked toxin, and may be converted into the latter by treatment with trypsin, and it is concluded that toxin consists of a mixture of two similar proteins of molecular weight about 63,000.
Related Papers (5)
Different biological properties of the two constituent peptide chains of ricin, a toxic protein inhibiting protein synthesis.
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Isolation and properties of abrin: a toxic protein inhibiting protein synthesis. Evidence for different biological functions of its two constituent-peptide chains.
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