PROTEIN SYNTHESIS IN DARK-GROWN BEAN LEAVES

1965 ◽  
Vol 43 (7) ◽  
pp. 817-824 ◽  
Author(s):  
David Racusen ◽  
Murray Foote
Keyword(s):  
Protein Synthesis ◽  
Soluble Protein ◽  
Specific Activity ◽  
Disc Electrophoresis ◽  
Protein Zone ◽  
Bean Leaves

RuDP carboxylase was present in 4-day-old, dark-grown bean leaves. The enzyme increased during subsequent dark growth and in 11 days reached one-third of the specific activity of a light-grown control. Preparative disc electrophoresis of the soluble protein revealed a zone symmetrical with RuDP carboxylase. Increases in RuDP carboxylase during dark growth were matched by corresponding increases in this protein zone. The correlation indicated that the enzyme accounted for 45% of the soluble protein in 11-day-old, light-grown leaves. The formation of peroxidase and catalase was much slower than the formation of RuDP carboxylase during dark growth.

Protein synthesis during Ilyanassa development: effect of the polar lobe

Development ◽  
1973 ◽  
Vol 29 (2) ◽  
pp. 267-281
Author(s):  
G. Teitelman
Keyword(s):  
Protein Synthesis ◽  
Normal Development ◽  
Disc Electrophoresis ◽  
Developmental Differences ◽  
Protein Solutions ◽  
Polar Lobe ◽  
Stages Of Development ◽  
Morphogenetic Factors ◽  
Slow Moving ◽  
The One

Removal of the polar lobe at the trefoil stage of the first cleavage division of Ilyanassa embryos causes abnormalities much later in development. To determine if the developmental differences between normal and delobed embryos were reflected in alterations in protein synthesis and at what stages of development these become evident, protein solutions were separated by disc electrophoresis on basic acrylamide gels. For the analysis of the newly synthesized proteins, two protein samples, one labelled with 14C and the other with 3H, were combined in the same electrophoretic column. Each was prepared from normal embryos or lobeless embryos at different stages of development. The distribution of the two groups of differentially labelled proteins was compared by a determination, for each fraction, of the ratio of the normalized 3H/14C counts for that particular fraction (R = 3H/14C). The plot of R versus fraction number was studied for various combinations of samples. During normal development the profile of labelled proteins remains unchanged until the onset of visible differentiation. At this stage, around day 4 of development, there are changes in biosynthesis revealed by a greater emphasis on the synthesis of slow moving proteins. The profile of labelled proteins of lobeless embryos remains unchanged up to the 5th day of development. This result is correlated with the absence, in the lobeless embryos, of many of the visible differentiations. Preliminary studies revealed that the spectrum of labelled proteins of the polar lobe is identical to the one present in lobeless embryos and in normal embryos in early stages of development. This suggests the possibility that the morphogenetic factors associated with the polar lobe are not among the newly synthesized proteins. A hypothesis is presented to account for the effects on morphogenesis and protein synthesis which are produced by removal of the polar lobe.

Stimulation of transport of alpha-aminoisobutyric acid into the testes of immature mice in vivo by follicle-stimulating hormone

1982 ◽  
Vol 100 (1) ◽  
pp. 137-142
Author(s):  
Nila Oza ◽  
Sarah J. Meanock ◽  
A. G. Davies
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Amino Acid Transport ◽  
Specific Activity ◽  
Follicle Stimulating Hormone ◽  
Acid Transport ◽  
Aminoisobutyric Acid ◽  
Old Mice ◽  
Stimulation Of

Abstract. Groups of immature mice were injected sc with radiocarbon-labelled alpha-aminoisobutyric acid (AIB) after being given a single sc injection of hFSH or of 0.9% saline. As an index of the transport of AIB, the specific activity of isotope was measured in homogenates of testis and of liver. FSH treatment caused statistically significant increases in the specific activity of isotope in the testes and in the ratio of testicular to liver specific activity. The effect was greatest in 9-day-old mice injected with FSH 16 h before removal of the testes. Uptake of labelled AIB was not stimulated after administration of hCG or testosterone. Doses of cycloheximide sufficient to reduce the rate of protein synthesis by over 99% did not impair testicular uptake of labelled AIB or the influence of FSH on AIB uptake. These results suggest that FSH stimulates amino acid transport into cells of the immature testis and that this action is independent of the stimulatory effect of FSH on testicular protein synthesis.

Changes in protein during development of Triturus embryos

Development ◽  
1973 ◽  
Vol 30 (3) ◽  
pp. 647-659
Author(s):  
Hiroshi Imoh ◽  
Tsutomu Minamidani
Keyword(s):  
Protein Synthesis ◽  
Protein Content ◽  
Sodium Carbonate ◽  
Dna Content ◽  
Total Protein ◽  
Soluble Protein ◽  
Nuclear Protein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Tail Bud ◽  
Stage Of Development

The present paper reports basic data on DNA content, protein content, and protein synthesis in Triturus pyrrhogaster embryos during development from cleavage to the hatching stage. Except for measurements of DNA and total protein contents, embryos were labeled with sodium carbonate-14C for 10 h and fractionated into embryonic cell components, i.e. cytoplasmic mass, yolk and pigment granules, and nuclei, in a discontinuous density gradient of sucrose. The protein content and the radioactivity incorporated into protein were measured in each fraction. Those fractions combining protein soluble in buffer at pH 8·3 and in 0·25 N-HCl were further studied with polyacrylamide gel electrophoresis. In the newt embryo, four stages of active DNA increase were observed when cultured at constant temperature; they were gastrula, neurula, late tail-bud, and before-hatching stages. Total protein per embryo decreased from 3 to 2 mg during the development studied. The content of cytoplasmic soluble protein per embryo was low and constant throughout development. Synthesis of the fraction was observed at the earliest stage of development studied though the rate was not high and specific activity of the soluble protein increased during development. Qualitative changes in the newly synthesized protein were observed. With the yolk fraction, synthesis of protein, other than from probable contamination with the cytoplasmic fraction, was not detected and a detailed description was omitted. Changes were observed at two stages of development in the synthesis of nuclear protein soluble in buffer at pH 8·3, the first at gastrulation and the second at late tail-bud stage. The change at gastrulation seemed to be the start of syntheses of the nuclear soluble proteins, while quantitative enhancement rather than qualitative change was noticed at late tail-bud stage. Most of the nuclear protein soluble in 0·25 N-HCI was histone. The histone content increased in accordance with increase in the DNA content and the rate of DNA accumulation was accompanied by proportionate incorporation of radioactivity into histone. Among histone fractions, unique behaviour of the very lysine-rich histone was observed. The availability of [14C]sodium carbonate in rough estimations of protein synthesis in embryos and significance of the data obtained have been discussed.

Plasma reciprocal pool specific activity predicts that of intracellular free leucine for protein synthesis

1989 ◽  
Vol 257 (3) ◽  
pp. E385-E399 ◽  
Author(s):  
F. F. Horber ◽  
C. M. Horber-Feyder ◽  
S. Krayer ◽  
W. F. Schwenk ◽  
M. W. Haymond
Keyword(s):  
Protein Synthesis ◽  
Striated Muscle ◽  
Specific Activity ◽  
Intracellular Space ◽  
Tissue Compartments ◽  
Venous Plasma

We previously proposed that, during the infusion of either labeled leucine or its alpha-ketoacid, alpha-ketoisocaproate (KIC), the plasma specific activity (SA) of the transaminated product of the infused tracer ("reciprocal pool SA") may better reflect the intracellular leucine SA than the plasma SA of either infused tracer ("primary pool SA"). To test this hypothesis, 14 dogs were simultaneously infused intravenously with [3H]leucine and [14C]KIC, and blood and tissue compartments were sampled. The ratios of [3H]-leucine to [14C]leucine [( 3H]/[14C]leucine) in mixed tissue proteins and in the intracellular space of striated muscle were the same as the ratio of the isotope infusion rates and similar, although slightly lower (P less than 0.01), than [3H]KIC/[14C]leucine SA (ratio of reciprocal pool SA) in plasma. Plasma [3H]KIC/[14C]leucine SA were essentially identical to the [3H]/[14C] of leucine in 1) mixed liver proteins, 2) intrahepatic free leucine, and 3) fibrin. The [3H]/[14C]leucine in mixed renal proteins and in the intracellular space of kidney and erythrocytes were similar to those of the venous plasma [3H]/[14C]leucine SA. The plasma [3H]KIC and [14C]leucine SA (the reciprocal pool SA) were similar to the SA of [3H]- and [14C]leucine in the intracellular space of all organs investigated with the exception of kidney. Therefore, in postabsorptive dogs, the plasma SA of the transaminated product of the infused labeled KIC or leucine is an excellent predictor of the intracellular leucine SA in all tissues investigated with the exception of kidney.

Insulin stimulation of protein synthesis in cultured skeletal and cardiac muscle cells

1982 ◽  
Vol 243 (1) ◽  
pp. C81-C86 ◽  
Author(s):  
J. Airhart ◽  
J. A. Arnold ◽  
W. S. Stirewalt ◽  
R. B. Low
Keyword(s):  
Protein Synthesis ◽  
Specific Activity ◽  
Muscle Cells ◽  
Cell Types ◽  
Cardiac Cells ◽  
Cardiac Muscle Cells ◽  
Significant Stimulation ◽  
Chick Heart ◽  
Embryonic Chick Heart ◽  
Stimulation Of

The effects of acute exposure to insulin on protein synthesis were examined in primary, differentiated cultures of embryonic chick heart and skeletal muscle cells. Synthetic rates were calculated using the specific activity of tRNA-bound leucine as precursor, a specific activity that was significantly less than that of extracellular leucine but greater than that of free, intracellular leucine at 0.2 mM external leucine. Insulin did not alter these relationships. Doses of insulin in the physiological range produced significant stimulation of protein synthesis in both cell types. Maximal responses, involving approximately 30% increases in both absolute and fractional rates, were observed at higher insulin concentrations. Significant stimulation by insulin was seen in cardiac cells after only 1 h of insulin treatment, and the effects of the hormone were observed both in the presence and absence of serum in the culture medium.

Regulation of cardiac protein balance by hydrocortisone: interaction with insulin.

1978 ◽  
Vol 234 (3) ◽  
pp. E306
Author(s):  
E E Griffin ◽  
K Wildenthal
Keyword(s):  
Protein Synthesis ◽  
Protein Degradation ◽  
Cathepsin D ◽  
Specific Activity ◽  
Branched Chain Amino Acids ◽  
Protein Balance ◽  
Net Uptake ◽  
Specific Activities ◽  
Branched Chain ◽  
Net Release

In fetal mouse hearts in organ culture the rate of protein synthesis was substantially reduced and the rate of protein degradation slightly increased by hydrocortisone in the absence of insulin, but in the presence of insulin the steroid caused a small increase in protein synthesis and a significant reduction in protein degradation. Hydrocortisone promoted the net uptake (or reduced the net release) of branched-chain amino acids independent of insulin and independent of simultaneous changes in protein balance. The specific activities of the lysosomal enzymes cathepsin D and glucosaminidase were reduced by hydrocortisone in all media, whereas the specific activity of creatine kinase increased when the medium contained insulin but decreased in the absence of insulin. It is concluded that hydrocortisone regulates cardiac protein balance via alterations both in synthesis and in degradation. Some of the hormone's myocardial effects are influenced by insulin so that hydrocortisone is anabolic in its presence but catabolic in its absence.

Haemolymph protein metabolism during the fifth instar of Locusta

1970 ◽  
Vol 48 (2) ◽  
pp. 297-304 ◽  
Author(s):  
S. S. Tobe ◽  
B. G. Loughton
Keyword(s):  
Protein Metabolism ◽  
Specific Activity ◽  
Protein A ◽  
Disc Electrophoresis ◽  
The Other ◽  
Blood Protein ◽  
Blood Proteins ◽  
Concentration Changes ◽  
The Common

Selected blood proteins were studied during the fifth instar of Locusta by means of acrylamide 'disc electrophoresis' after injection of 3H-labeled blood proteins or 3H-leucine. Label was found to accumulate in the "common protein" fraction in the middle of the instar after injection of labeled blood protein. The specific activity of the other blood proteins studied followed the pattern predicted by their concentration changes. The specific activity of blood proteins after injection of 3H-leucine was generally high during the early part of the instar and fell after 152 h. Most activity was found in the "common protein." A program of protein metabolism for the fifth-instar locust is suggested on the basis of these and earlier results.

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