Inhibition by α-methyl-norvaline of valine and leucine uptake into protein in the chick embryo

Development ◽  
1965 ◽  
Vol 13 (3) ◽  
pp. 275-283
Author(s):  
E. M. Deuchar ◽  
A. M. L. Dryland
Keyword(s):  
Amino Acid ◽  
Chick Embryo ◽  
Recent Work ◽  
Leucine Uptake ◽  
Area Vasculosa ◽  
Abnormal Haemoglobin ◽  
Haemoglobin Molecule ◽  
Haemoglobin Synthesis

In an earlier publication (Deuchar & Dryland, 1964) it was reported that α-methyl-norvaline, an amino acid described by Ross et al. (1961), whose structure resembles that of both valine and leucine (see below), caused a visible reduction in the quantity of haemoglobin formed by explants of the area vasculosa of the 48-hr, chick embryo, as compared with controls explanted without the analogue present. The structure of the haemoglobin molecule in birds has not yet been fully worked out, but according to recent work (reviewed by Gratzer & Allison, 1960) there are at least four N-terminal valine groups, two of which have leucine adjacent to them. The inhibition of haemoglobin synthesis by α-methyl-norvaline might, therefore, be due to competition with valine or leucine for uptake into these terminal sites on the peptide chains of the globin. The analogue might itself be taken up in their place, forming an abnormal haemoglobin.

scholarly journals Inhibition by α-methyl-norvaline of the uptake of valine and leucine into haemoglobin of the chick embryo

Development ◽  
1966 ◽  
Vol 15 (3) ◽  
pp. 291-295
Author(s):  
E. M. Deuchar ◽  
A. M. L. Dryland
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Chick Embryo ◽  
Special Interest ◽  
Chick Embryos ◽  
Area Vasculosa

We reported recently (Deuchar & Dryland, 1965) that α-methyl-norvaline, an amino acid whose structure resembles both valine and leucine, inhibits the uptake of these two normal amino- acids into protein in explanted chick embryos and is also itself incorporated into embryonic proteins. Since the first effect of α-methyl-norvaline that we had noted (Deuchar & Dryland, 1964) was a reduction in the quantity of haemoglobin formed in the cells of the area vasculosa, it was of special interest to see whether this inhibitor blocked the uptake of valine and/or leucine into haemoglobin in particular and whether it was at the same time taken up itself into haemoglobin. The results of experiments in which haemoglobin has been extracted from area vasculosa explants and the uptake of radioactively labelled amino acids into it has been measured, are reported here.

The effects of D- and L-threo-chloramphenicol on the early development of the chick embryo

Development ◽  
1965 ◽  
Vol 13 (3) ◽  
pp. 341-356
Author(s):  
F. S. Billett ◽  
Rosalba Collini ◽  
Louie Hamilton
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Chick Embryo ◽  
Messenger Rna ◽  
Mammalian Cells ◽  
Animal Cells ◽  
Inhibit Protein Synthesis ◽  
Acid Complex ◽  
Amino Acid Complex ◽  
Bacterial Systems

In many bacterial systems chloramphenicol has been shown to inhibit protein synthesis (Hahn & Wisseman, 1951; Gale & Folkes, 1953). The precise mechanism of this inhibition is not clear, although the evidence suggests that the interaction of the soluble RNA-amino acid complex with the ribosomes is prevented because the attachment of the messenger RNA to the ribosomes is itself impaired (Lacks & Gros, 1959; Nathans & Lipman, 1961; Jardetsky & Julian, 1964; Julian & Jardetsky, 1964). In contrast to its effect on bacterial systems, chloramphenicol has been reported to have little or no action on the protein synthesis by cell-free extracts of mammalian cells (Rendi, 1959; Ehrenstein & Lipmann, 1961). A basis for this resistance has been proposed by Vazquez (1964), who finds that whereas bacterial ribosomes bind chloramphenicol, ribosomes from other organisms do not. Nevertheless, it cannot be stated with any confidence that chloramphenicol has no effect on the protein synthesis of animal cells.

Effect of a Leucine Analogue on Incorporation of Glycine into the Proteins of Explanted Chick Embryos

Development ◽  
1958 ◽  
Vol 6 (2) ◽  
pp. 262-269
Author(s):  
Phyllis W. Schultz ◽  
Heinz Herrmann
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Chick Embryo ◽  
Total Protein ◽  
Nutrient Medium ◽  
Chick Embryos ◽  
Agar Gel ◽  
Egg Extract ◽  
Amino Acid Analogues

Amino acid analogues have been observed to give rise to abnormal forms of development of chick and amphibian embryos (Herrmann, 1953; Rothfels, 1954; Waddington & Sirlin, 1954; Feldman & Waddington, 1955; Herrmann, Rothfels-Konigsberg, & Curry, 1955). Assuming that these disturbances may be due to interference with the utilization of amino acids for protein formation, we have attempted an analysis of this effect by comparison of the protein contents and of the uptake of glycine into the proteins of chick embryo explants in the presence and absence of amino acid analogues. The results of such experiments are reported in this paper. The chick embryos used for explanation, the explantation technique, and the determination of total protein glycine and of tracer glycine were essentially the same as described previously (Herrmann & Schultz, 1958). The embryos were explanted at the 11–13 somite stage on to the surface of an agar gel containing egg extract as nutrient medium following the procedure given by Spratt (1947) as modified by Rothfels (1954).

Impaired energy metabolism as an initial step in the mechanism for 6-aminonicotinamide-induced limb malformation

Development ◽  
1980 ◽  
Vol 59 (1) ◽  
pp. 217-222
Author(s):  
Yal C. Sheffield ◽  
Robert E. Seegmiller
Keyword(s):  
Amino Acid ◽  
Energy Metabolism ◽  
Chick Embryo ◽  
Chondroitin Sulfate ◽  
Atp Synthesis ◽  
Initial Step ◽  
Chick Embryos ◽  
Impaired Energy Metabolism ◽  
All Treatment

The analogue and antagonist of nicotinamide, 6-aminonicotinamide (6-AN), impairs cartilage formation and results in shortening of the limbs when administered to chick embryos. Studies have shown that 6-AN forms an abnormal NAD analogue which inhibits the activity of NAD-dependent enzymes associated with production of ATP. To determine if an effect on ATP synthesis might be associated with the mechanism of teratogenesis in the chick embryo, ATP levels of cartilage from day-8 chick embryos treated in vitro were assayed in relation to biosynthesis of protein, DNA and chondroitin sulfate. Incorporation of 35SO4− was inhibited by 6 h of treatment with 10 µg/ml of 6-AN, whereas incorporation of [3H]thymidine and [3H]amino acid was not inhibited until 12 h. Incorporation of [3H]- glucosamine was increased at all treatment times. A decrease in the level of ATP preceded any detectable inhibition of precursor incorporation. These results are consistent with the hypothesis that 6-AN inhibits chondroitin sulfate synthesis through a reduction in the level of ATP in chondrocytes.

Induction of experimental phenylketonuria-like conditions in chick embryo. Effect on amino acid concentration in brain, liver and plasma

1984 ◽  
Vol 6 (4) ◽  
pp. 485-489 ◽  
Author(s):  
C. Marco ◽  
M.J. Alejandre ◽  
M.F. Zafra ◽  
J.L. Segovia ◽  
E. Garcia-Peregrin
Keyword(s):  
Amino Acid ◽  
Chick Embryo ◽  
Acid Concentration ◽  
Amino Acid Concentration

scholarly journals The control of haemoglobin synthesis: factors controlling the output of α and β chains

1969 ◽  
Vol 28 (02) ◽  
pp. 248-254 ◽  
Author(s):  
R. T. Hunt ◽  
A. R. Hunter ◽  
A. J. Munro
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Rna Synthesis ◽  
Amino Acid Starvation ◽  
Control Mechanisms ◽  
Actual Process ◽  
Haemoglobin Synthesis

Analysis of the effects of amino acid starvation in reticulocytes is comparatively simple compared with similar analysis in other tissues of whole organisms. This is mainly because of the absence of RNA synthesis in reticulocytes, but also because the bulk of the protein being synthesized is haemoglobin, a protein whose structure is completely known. The absence of RNA synthesis eliminates complications that would otherwise arise through RNA-mediated control mechanisms which in turn might mask the effects of amino acid starvation on the protein synthetic machinery in the cells (Munro, 1969). Consequently reticulocytes have been used to study the effect of amino acid starvation on the actual process of protein synthesis and assembly.

Myocardial amino acid transport by canine sarcolemma vesicles

1987 ◽  
Vol 252 (6) ◽  
pp. H1070-H1076
Author(s):  
L. H. Young ◽  
B. L. Zaret ◽  
E. J. Barrett
Keyword(s):  
Amino Acid ◽  
Sarcoplasmic Reticulum ◽  
Membrane Vesicles ◽  
Amino Acid Uptake ◽  
Ventricular Myocardium ◽  
Transport Systems ◽  
Acid Uptake ◽  
Leucine Uptake ◽  
Alanine Transport ◽  
Canine Ventricular Myocardium

The transport of L-alanine and L-leucine into membrane vesicles isolated from mature canine ventricular myocardium was studied. Transport was assessed in purified sarcolemma and in vesicles differentially enriched either for sarcolemma or sarcoplasmic reticulum to further localize these transport systems. An imposed inward gradient of a NaNO3 stimulated uptake of L-alanine but not L-leucine by these vesicles. Amino acid uptake by these vesicles occurred into an osmotically active space. The stimulatory effect of Na+ on alanine transport was most striking in the purified sarcolemma vesicles, where Na+-stimulated alanine flux was 45 +/- 14 pmol X mg-1 X min-1. Furthermore, Na+-dependent alanine transport activity appeared to copurify with Na+-K+-ATPase activity, which served as a marker for sarcolemma membrane when these activities were compared in the three different membrane preparations. Leucine transport by sarcolemma was not altered by an imposed Na+ gradient. However, leucine uptake was a saturable function of extravesicular leucine and was inhibited by valine. In contrast, in sarcoplasmic reticulum membrane vesicles leucine uptake increased proportionately with increasing media leucine and was unaffected by valine. Our results demonstrate the feasibility of directly studying the transport of naturally occurring amino acids in membrane vesicles from mammalian heart, and the presence of Na+-dependent alanine transport system and a Na+-independent leucine transporter in the sarcolemma but not in sarcoplasmic reticulum of canine ventricular myocardium.

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