Penicillin biochemical effects

The biochemical basis of penicillin action continues to be an area of active investigation. Penicillins are highly specific inhibitors of enzyme(s) involved in the synthesis of the bacterial cell wall, a structure not present in mammalian cells. Three principal factors are thought to be important for effective antibacterial action by a penicillin ... 

METHOTREXATE PENICILLINS t plasma concentrations of methotrexate and risk of toxic effects of methotrexate, e.g. myelosuppression, liver cirrhosis, pulmonary toxicity Penicillins 1 renal elimination of methotrexate by renal tubular secretion, which is the main route of elimination of methotrexate. Penicillins compete with methotrexate for renal elimination. Displacement from proteinbinding sites may occur and is only a minor contribution to the interaction Avoid concurrent use. If concurrent use is necessary, monitor clinically and biochemically for blood dyscrasia, liver toxicity and pulmonary toxicity. Do FBCs and LFTs prior to concurrent treatment... 

Various p-lactam antibiotics such as cephalosporins and guanylureido penicillins may cause nonimmuno-logic nephrotoxic effects. The elucidation of the precise biochemical mechanisms involved in nephrotoxicity of P-lactams is of obvious importance for their rational and efficient utilization in the clinical management of infectious disease and for development of future cephalosporins. 

This discussion is not complete, however, as the methods of administration — oral, intravenous, or intramuscular — and the dosage levels and frequency, as well as other factors, must be estabhshed for successful clinical therapy. Thus, a drug or remedy may be effective if administered intravenously but not orally, because the digestive processes may affect the drug itself. An exception is penicillin and some other antibiotics, which can be successfully used orally. And it can be added that there are such peripheral matters that in vitro, in vivo, and clinical test results do not always agree. There is also biochemical individuality among patients, with the result that what works on one does not necessarily work on another. 

Mishra A, Debnath M (2002) Effect of pH on simultaneous saccharification and isomerization by glucoamylase and glucose isomerase. Appl Biochem Biotechnol 102-103 193-199 Mislovicova D, Masarova J, Buco M et al. (2006) Stability of penicillin G acylase modified with various polysaccharides. Enzyme Microb Technol 39 579-585 Monte WC (1999) Ice cream containing a lactose enzyme composition and method. US Patent 5942264. Issued on August 24, 1999... 

Abraham EP, Newton GGE (1961) The structure of cephalosporin C. Biochem J 79(2) 377-393 Aguirre C, Toledo M, Medina V et al. (2002) Effect of cosolvent and pH on the kinetically controlled synthesis of cephalexin with immobilised penicillin acylase. Proc Biochem 38(3) 351-360... 

Kim MG, Lee SB (1996) Penicillin acylase-catalyzed synthesis of P-lactam antibiotics in water-methanol mixtures effect of cosolvent content and chemical nature of substrate on reaction rates and yields. J Mol Catal B Enzym 1 201-211 Kohsaka M, Domain AL (1976) Conversion of penicDlin N to cephalosporin(s) by ceU-free extracts of Cephalosporium acremonium. Biochem Biophys Res Commun 70(2) 465-473 Koreishi M, Tani K, Ise Y et al. (2007) Enzymatic synthesis of P-lactam antibiotics and /V-fatty-acylated amino compounds by the acyl transfer reaction catalyzed by peniciUin V acylase from Streptomyces mobaraensis. Biosci Biotechnol Biochem 71(6) 1582-1586 Kupka JY, Shen, YQ, Wolfe S et al. (1983) Partial purification and properties of the alpha-ketoglutarate-linked ring expansion enzyme of beta-lactam biosynthesis of Cephalosporium acremonium. FEMS Microbiol Lett 16 1-6... 

The full significance of penicillin as an effective antibiotic was recognised by Howard W. Florey and Ernst B. Chain (1940). This discovery stimulated intensive research toward the biotechnical production of penicillin. It was possible to increase production from a few milligrams of penicillin per liter of culture broth to a level of 35 g/1 by mutation of the strain and improvements in biochemical process technology. Figure 6.5 shows the production flow diagram for penicillin G. 

The benefits of modifying EIS structures with LbL films to achieve biosensors with improved performance was also reported by Abouzar et al., who observed an amplification of the signal response upon alternating layers of polyelectrolytes and enzymes as gate membranes on the p-Si-Si02 EIS structure [99]. A new variant of EIS sensors has been produced, which comprised an array of individually addressable nanoplate field-effect capacitive biochemical sensors with an SOI (silicon-on-insulator) stmcture to determine pH and detect penicillin. It also allows for the label-free electrical monitoring of formation of polyelectrolyte multilayers and DNA (deoxyribonucleic acid)-hybridization event [100]. 

Katz E, Weissbach H. Effect of chloromycetin and penicillin on the incorporation of amino acids into actinomycin and protein by Streptamyces onribidticus- Biochem Biof4rys Res Com-... 

Slade A, Hotrocks AJ, Lindsay CD, Dunbar B, Virden R. SitC directed chemical conversion of serine to cysteine in penicillin acylase from Escfiertc/iia coli ATCCl 1105. Effect on conformation and catalytic activity. Eur J Biochem 1991 197 75-80. 

Arnstein, H. R. V., and H. Margreiter The biosynthesis of penicillin. 7. Further experiments on the utilization of l- and D-valine and the effect of cystine and valine analogues on penicillin biosynthesis. Biochem. J. 68, 399 (1958). 

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