RNA protein synthesis

Mechanism of Action An alkylating agent that inhibits DNAand RNA protein synthesis by cross-linking with DNA and RNA strands, preventing cell growth. Cell cycle-phase nonspedflc. Therapeutic Effect Potent immunosuppressant. Pharmacokinetics Well absorbed from the G1 tract. Protein binding low. Crosses the blood-brain barrier. Metabolized in the liver to active metabolites. Primarily excreted in urine. Removed by hemodialysis. Half-life 3-12 hr. 

Mechanism of Action A folate antagonist that inhibits the enzyme dihydrofolate reductase (DHFR). Therapeutic Effect Disrupts purine, DNA, RNA, protein synthesis,... 

The antibacterial action of erythromycin may be inhibitory or bactericidal, particularly at higher concentrations, for susceptible organisms. Activity is enhanced at alkaline pH. Inhibition of protein synthesis occurs via binding to the 50S ribosomal RNA. Protein synthesis is inhibited because aminoacyl translocation reactions and the formation of initiation complexes are blocked (Figure 44-... 

Steroid hormone receptors (for gonadal steroids and adrenocortical steroids) are complex proteins inside the target cell. The steroid penetrates, is bound and translocates into the cell nucleus, which is the principal site of action and where RNA/protein synthesis occurs. Compounds that occupy the receptor without causing translocation into the nucleus or the replenishment of receptors act as antagonists, e.g. spironolactone to aldosterone, cyproterone to androgens, clomiphene to oestrogens. 

Antipurine antimetabolite purine analog inhibits DNA, RNA, protein synthesis metabolized by xanthine oxidase... 

DNA/RNA/protein synthesis, not only for cancerous cells, but for all cells, hence the designator cytotoxic. 

Conventional chemotherapy drugs act as inhibitors for enzymes, notably for critical enzymes that pertain to DNA/RNA/protein synthesis. The idea is that by blocking one or another or all of these enzymes, cancer cell growth and proliferation will be stopped. Unfortunately, these drugs are nonselective, acting against normal cells as well, and are therefore categorized as cell toxic, or cytotoxic. 

Proteins involved in DNA, RNA, protein synthesis Gene regulation Cancer and control of cell proliferation... 

Lomustine is a nitrosourea. Its mechanism of action involves the inhibition of both DNA and RNA synthesis through DNA alkylation. Lomustine has been shown to affect a number of cellular processes including RNA, protein synthesis, and the processing of ribosomal and nucleoplasmic messenger RNA DNA base component structure and the rate of DNA synthesis and DNA polymerase activity. It is cell-cycle nonspecific. It is indicated in the treatment of brain tumors and Hodgkin s disease in adults and children. 

According to the cascade DNA- RNA- protein synthesis, disturbances of protein synthesis should be accompanied by alterations of RNA-metabolism. These are traceable by measuring "one way" urinary methylated RNA-catabolites. ... 

Ribosome Protein synthesis factory consisting of two differently sized subunits of ribonucleoprotein complexes with several active centers. It travels along mRNA and reads triplet codons for individual amino acids which are brought in by transfer RNAs via base pairing with cognate anticodon sequences in these RNAs. Protein synthesis occurs on the ribosome to which the growing polypeptide chain remains attached. 

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