Biomaterial Database

Peptidyl transferase activity in rat skeletal muscle ribosomes after protein restriction. 1977

A von der Decken

Rats were fed for 6 consecutive days a diet containing casein supplemented with 3 g/kg methionine. The protein level was either 20% or 3%. Skeletal muscle ribosomes were isolated and the activity of the ribosomal enzyme peptidyl transferase was determined. [3H]puromycin acted as acceptor for tRNA bound peptide provided it was located at the ribosomal peptidyl site. The results showed that the rate of peptidyl transferase activity was 13% lower after protein restriction. The differences amounted to 6% when diphtheria toxin and NAD were added as an inhibitor of elongation factor2. This factor catalyzes translocation of peptidyl-tRNA from ribosomal acceptor to peptidyl site. Between 0.11 and 0.15 pmoles peptidyl-tRNA per pmole ribosome were originally accessable as a substrate for peptidyl transferase. The results indicate that peptidyl transferase contributes to a decrease in protein synthesis after protein restriction; but that other components also contribute to the decrease observed.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008297	Male		Males
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D009243	NAD	A coenzyme composed of ribosylnicotinamide 5'-diphosphate coupled to adenosine 5'-phosphate by pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). (Dorland, 27th ed)	Coenzyme I,DPN,Diphosphopyridine Nucleotide,Nadide,Nicotinamide-Adenine Dinucleotide,Dihydronicotinamide Adenine Dinucleotide,NADH,Adenine Dinucleotide, Dihydronicotinamide,Dinucleotide, Dihydronicotinamide Adenine,Dinucleotide, Nicotinamide-Adenine,Nicotinamide Adenine Dinucleotide,Nucleotide, Diphosphopyridine
D010445	Peptide Elongation Factors	Protein factors uniquely required during the elongation phase of protein synthesis.	Elongation Factor,Elongation Factors, Peptide,Factor, Elongation,Factors, Peptide Elongation
D010458	Peptidyl Transferases	Acyltransferases that use AMINO ACYL TRNA as the amino acid donor in formation of a peptide bond. There are ribosomal and non-ribosomal peptidyltransferases.	Peptidyl Transferase,Peptidyl Translocase,Peptidyl Translocases,Peptidyltransferase,Transpeptidase,Transpeptidases,Peptidyltransferases,Transferase, Peptidyl,Transferases, Peptidyl,Translocase, Peptidyl,Translocases, Peptidyl
D011488	Protein Deficiency	A nutritional condition produced by a deficiency of proteins in the diet, characterized by adaptive enzyme changes in the liver, increase in amino acid synthetases, and diminution of urea formation, thus conserving nitrogen and reducing its loss in the urine. Growth, immune response, repair, and production of enzymes and hormones are all impaired in severe protein deficiency. Protein deficiency may also arise in the face of adequate protein intake if the protein is of poor quality (i.e., the content of one or more amino acids is inadequate and thus becomes the limiting factor in protein utilization). (From Merck Manual, 16th ed; Harrison's Principles of Internal Medicine, 12th ed, p406)	Deficiency, Protein,Deficiencies, Protein,Protein Deficiencies
D011691	Puromycin	A cinnamamido ADENOSINE found in STREPTOMYCES alboniger. It inhibits protein synthesis by binding to RNA. It is an antineoplastic and antitrypanosomal agent and is used in research as an inhibitor of protein synthesis.	CL-13900,P-638,Puromycin Dihydrochloride,Puromycin Hydrochloride,Stylomycin,CL 13900,CL13900,P 638,P638
D004167	Diphtheria Toxin	An ADP-ribosylating polypeptide produced by CORYNEBACTERIUM DIPHTHERIAE that causes the signs and symptoms of DIPHTHERIA. It can be broken into two unequal domains: the smaller, catalytic A domain is the lethal moiety and contains MONO(ADP-RIBOSE) TRANSFERASES which transfers ADP RIBOSE to PEPTIDE ELONGATION FACTOR 2 thereby inhibiting protein synthesis; and the larger B domain that is needed for entry into cells.	Corynebacterium Diphtheriae Toxin,Toxin, Corynebacterium Diphtheriae
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man