Biomaterial Database

Modifications of 60 S ribosomal subunits induced by the ricin A chain. 1986

A Paleologue, and J P Reboud, and A M Reboud

Incubation of 60 S ribosomal subunits with the ricin A chain reduced their stability during heat treatment. The toxin shifted the thermal denaturation curve of the subunits towards lower temperatures, in a similar way to that produced by the decrease in Mg2+ concentration. A brief heating (3 min at 57 degrees C), which did not affect control subunit activity, enhanced protein synthesis inhibition of the toxin-treated subunits that released more 5 S RNA, in the form of nucleoprotein complex(es) with protein L5 and phosphoproteins P1P2 (RNPH), than did heated control subunits [(1984) Eur. J. Biochem. 143, 303-307]. No nuclease activity tested on 60 S subunits and purified 5 S and 5.8 S RNA was found associated with the toxin. The results suggest that the toxin induced a limited conformational change of the 60 S subunit, which destabilized the interaction between RNPH and the rest of the subunit.

UI	MeSH Term	Description	Entries
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
D006358	Hot Temperature	Presence of warmth or heat or a temperature notably higher than an accustomed norm.	Heat,Hot Temperatures,Temperature, Hot,Temperatures, Hot
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012260	Ribonucleases	Enzymes that catalyze the hydrolysis of ester bonds within RNA. EC 3.1.-.	Nucleases, RNA,RNase,Acid Ribonuclease,Alkaline Ribonuclease,Ribonuclease,RNA Nucleases,Ribonuclease, Acid,Ribonuclease, Alkaline
D012261	Ribonucleoproteins	Complexes of RNA-binding proteins with ribonucleic acids (RNA).	Ribonucleoprotein
D012270	Ribosomes	Multicomponent ribonucleoprotein structures found in the CYTOPLASM of all cells, and in MITOCHONDRIA, and PLASTIDS. They function in PROTEIN BIOSYNTHESIS via GENETIC TRANSLATION.	Ribosome
D012276	Ricin	A protein phytotoxin from the seeds of Ricinus communis, the castor oil plant. It agglutinates cells, is proteolytic, and causes lethal inflammation and hemorrhage if taken internally.	Castor Bean Lectin,Lectin, Castor Bean,Lectin, Ricinus,Ricin Toxin,RCA 60,RCA60,Ricin A Chain,Ricin B Chain,Ricin D,Ricin I,Ricinus Toxin,A Chain, Ricin,B Chain, Ricin,Ricinus Lectin,Toxin, Ricin,Toxin, Ricinus
D012335	RNA, Ribosomal	The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. (Dorland, 28th ed)	Ribosomal RNA,15S RNA,RNA, 15S
D013056	Spectrophotometry, Ultraviolet	Determination of the spectra of ultraviolet absorption by specific molecules in gases or liquids, for example Cl2, SO2, NO2, CS2, ozone, mercury vapor, and various unsaturated compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Ultraviolet Spectrophotometry