Protein synthesis temperature effects

Rapid-acting dermally hazardous cytotoxin that inhibits protein synthesis and affects clotting factors in the blood. It is capable of producing incapacitating or lethal effects. T2 is obtained from various molds and fungi (Fusarium sp.). It is a colorless crystalline solid of white powder that melts at 304°F. Impure samples may be a colorless to slightly yellow oil. It is slightly soluble in water, but soluble in ethyl acetate, acetone, ethanol, chloroform, methylene chloride, diethyl ether, and dimethyl sulfoxide (DMSO). It is heat stable and can be stored at room temperature for years. 

Most bodybuilders don t realize that the anabolic effects of Clenbuterol are not due to increased anabolic activity. Clenbuterol is actually effective through a different mechanism. It decreases both protein synthesis and break down. The reason anti-catabolic effects result is simply because it hinders protein break down more which shifts the ratio in favor of anabolism. This means that clenbuterol had significant anti-catabolic effects when stacked with a cortisol inhibitor post or during AAS cycles. Cytadren was an often noted example. Again, since clenbuterol increases thermal genesis, (calories released as heat) the common use of thyroid T-3 or T-4 in a stack with it caused a significant increase in body temperature. This was monitored closely by most. 

Haschemeyer, A.E.V., Persell, R. and Smith, M.A.K. (1979). Effect of temperature on protein synthesis in fish of the Galapagos and Perlas Islands. Comparative Biochemistry and Physiology 64B, 91-95. 

Figure 7.11. The effects of exposure temperature on protein synthetic patterns of isolated gill tissue from specimens of 13°C-acclimated Tegula funebralis. Autoradiographic images illustrate newly synthesized (35S-labeled) proteins of several size classes (molecular mass standards are shown in the left lane). Two specimens from each temperature of incubation are shown. At temperatures above 24°C, synthesis of heat-shock proteins in the molecular mass ranges of 38, 70, 77, and 90 kDa is induced. Hsp synthesis becomes an increasingly large fraction of protein synthesis as exposure temperature increases, and by 38°C, only synthesis of hsp70 is observed. By 39° C, no protein synthesis takes place. (Figure modified after Tomanek and Somero, 1999.)...

Brassinosteroids (BSs) represent a new group of plant hormones that possess a broad spectrum of physiological activities (1,2). A most Intriguing property of BSs Is their capacity to Increase stress resistance In plants, but the mechanism of such an antistress activity still remains unknown (1). As cell stress resistance Is usually associated with stress protein synthesis (3 4) our aim was to study the BS effect on protein synthesis and ultrastructure of wheat leaf cells at normal temperature and under heat shock conditions. We have also studied the Influence of BSs on mesophyll cell ultrastructure under saline stress. 

Once optimal conditions have been achieved for total expression, yield factors that influence folding and solubility must be examined these include the addition of cofactors, ligands, and chaperones. The reaction temperature may also have a dramatic effect on protein solubihty lowering it leads to lower rates of protein synthesis, but this can be compensated for by extending the reaction time. For example, expression of dihydrofolate reductase (DHFR) at 37 °C in a dialysis-mode E. coU reaction generally yields 2-3 mg of insoluble DHFR in 8 hours, but the same yield of mostly functional protein is obtained after 24 hours at 30 °C. 

The initial action of simazine and atrazine is the increase of nucleic acid synthesis. This increases protein synthesis and, thereby, the absorption of nitrate. However, nitrate reduction can occur only if sufficient carbohydrate is present for the formation of NADH. An increase in glucose catabolism increases the quantity of a-ketoglutaric acid. As a result of this assumed mechanism, nitrogen assimilation is increased at the expense of carbohydrates if there is not sufficient carbohydrate present, because the temperature is high and the light poor, or the nitrogen supply is good and, in this case, the. r-triazine effect is absent. 

Effects of nerve agents reported to be mediated by hormones include hyperglycemia, hyperlipidemia, increase in cyclic-AMP level, stimulation of protein synthesis, and decrease in brain RNA levels. Kokka et al. studied the time course of the change in temperature and plasma levels of corticosterone, growth hormone, and prolactin following administration of soman. There was an initial rise in corticosterone level after soman administration. The time course of hypothermia after soman did not correlate with the rise in corticosterone. 

The results presented indicate that an environmental factor, temperature, can reversibly affect the replicative ability of a genome by altering its secondary (and possibly, its tertiary) structure. Indeed, (i) these changes cannot be ascribed to enzymes involved in DNA replication, as in temperature-sensitive mutants, since the petites discussed here are iso-nuclear, and lack mitochondrial protein synthesis, like all petites (ii) the different effects of temperature on the replicative ability of petites Zl, 14 and 26 show an excellent correlation with those expected from the secondary structures of the postulated A-B fold and replacement folds (de Zamaroczy et al., 1981 1984), an effect on tertiary structures being also possible. 

In HeLa ceils hydroxyurea is an efficient inhibitor of histone synthesis. This action requires protein synthesis and leads to rapid disappearance of cytoplasmatic histone mRNA The effect is not specific for hydroxyurea since suppression of DNA synthesis by arabino-cytosine or temperature-sensitive mutations yields analogous results. Similarly, the synthesis of some enzymes necessary for DNA replication and active in S-phase is altered by hydroxyurea. Increased activity of ribonucleotide reductase in HeLa and in hamster cells and of the salvage enzyme thymidine kinase in HeLa cells and KB cells has been observed, probably as a consequence of the increased fraction of cells in S-phase. Repression occurs for thymidine kinase in human lymphocytes and for ornithine decarboxylase in Chinese hamster fibroblasts whereas no or only slight effects were seen on ribonucleotide reductase in hamster fibroblasts , on thymidylate synthase in extracts from synchronous mouse cells " , and on DNA polymerase in rabbit kidney cells or HeLa cells . ... 

---