Biological chemistry mechanisms

Human anatomy kinesiology physiology ergonomics biology chemistry mechanical engineering pathology mathematics physics psychology. 

Amide hydrolysis is common in biological chemistry. Just as the hydrolysis of esters is the initial step in the digestion of dietary fats, the hydrolysis of amides is the initial step in the digestion of dietary proteins. The reaction is catalyzed by protease enzymes and occurs by a mechanism almost identical to that we just saw for fat hydrolysis. That is, an initial nucleophilic acyl substitution of an alcohol group in the enzyme on an amide linkage in the protein gives an acyl enzyme intermediate that then undergoes hydrolysis. 

Sjbberg B-M (1997) Ribonucleotide Reductases - A Group of Enzymes with Different Metallosites and a Similar Reaction Mechanism. 88 139-174 Slebodnick C, Hamstra BJ, Pecoraro VL (1997) Modeling the Biological Chemistry of Vanadium Structural and Reactivity Studies Elucidating Biological Function. 89 51-108 Smit HHA, see Thiel RC (1993) 81 1-40... 

Rahmatullah, M. and Roche, T.E. (1985) Modification of bovine kidney pyruvate dehydrogenase kinase activity by CoA esters and their mechanism of action. Journal of Biological Chemistry 260, 10146—10152. 

Saz, H.J. and Weil, A. (1960) The mechanism of formation of a-methylbutyrate from carbohydrate by Ascaris lumbricoides muscle. Journal of Biological Chemistry 235, 914-918. 

Houston, K.M., Cushley, W.C. and Harnett, W. (1997) Studies on the site and mechanism of attachment of phosphorylcholine to a filarial excretory-secretory product. Journal of Biological Chemistry 272, 1527-1533. 

Hsu, K.-T. and Storch, J. (1996) Fatty acid transfer from liver and intestinal fatty acid-binding proteins to membranes occurs by different mechanisms. Journal of Biological Chemistry 271,13317—13323. 

Bogdan, C., Paik, J., Vodovotz, Y. and Nathan, C. (1992) Contrasting mechanisms for suppression of macrophage cytokine release by transforming growth factor-beta and interleukin-10. Journal of Biological Chemistry 267, 23301-23308. 

Estabrook, R.W., Hildebrandt, A.G., Baron, J., Netter, K.J. and Leibman, K. (1971) A new spectral intermediate associated with cytochrome P-450 function in liver microsomes. Biochemical and Biophysical Research Communications, 42 (1), 132-139. Pompon, D. and Coon, M.J. (1984) On the mechanism of action of cytochrome P-450. Oxidation and reduction of the ferrous dioxygen complex of liver microsomal cytochrome P-450 by cytochrome b5. Journal of Biological Chemistry, 259 (24), 15377-15385. Hildebrandt, A. and Estabrook, R.W. (1971) Evidence for the participation of cytochrome b 5 in hepatic microsomal mixed-function oxidation reactions. Archives of Biochemistry and Biophysics, 143 (1), 66-79. 

Augusto, O., Beilan, H.S. and Ortiz de Montellano, P.R. (1982) The catalytic mechanism of cytochrome P-450. Spin-trapping evidence for one-electron substrate oxidation. Journal of Biological Chemistry, 257 (19), 11288-11295. 

Burk, O., Tegude, H., Koch, I., Hustert, E., Wolbold, R., Glaeser, H., Klein, K., Fromm, M.F., Nuessler, A.K., Neuhaus, P., Zanger, U.M., Eichelbaum, M. and Wojnowski, L. (2002) Molecular mechanisms of polymorphic CYP3A7 expression in adult human liver and intestine. Journal of Biological Chemistry, 277, 24280-24288. 

Rothem, L., Aronheim, A., and Assaraf, Y.G. (2003) Alterations in the expression of transcription factors and the reduced folate carrier as a novel mechanism of antifolate resistance in human leukemia cells. Journal of Biological Chemistry. 278, 8935-8941. 

In summary, preliminary experiments have demonstrated that the efficiency and outcome of electron ionization is influenced by molecular orientation. That is, the magnitude of the electron impact ionization cross section depends on the spatial orientation of the molecule widi respect to the electron projectile. The ionization efficiency is lowest for electron impact on the negative end of the molecular dipole. In addition, the mass spectrum is orientation-dependent for example, in the ionization of CH3CI the ratio CHjCriCHj depends on the molecular orientation. There are both similarities in and differences between the effect of orientation on electron transfer (as an elementary step in the harpoon mechanism) and electron impact ionization, but there is a substantial effect in both cases. It seems likely that other types of particle interactions, for example, free-radical chemistry and ion-molecule chemistry, may also exhibit a dependence on relative spatial orientation. The information emerging from these studies should contribute one more perspective to our view of particle interactions and eventually to a deeper understanding of complex chemical and biological reaction mechanisms. 

Tanner, KG., Trievel, R.C., Kuo, M.H., Howard, R.M., Berger, S.L., Albs, C.D., Marmorstein, R. and Denu, J.M. (1999) Catalytic mechanism and function of invariant glutamic acid 173 from the histone acetyltransferase GCN5 transcriptional coactivator. The Journal of Biological Chemistry, 274 (26), 18157-18160. 

Structural basis for the NAD-dependent deacetylase mechanism of Sir2. The journal of Biological Chemistry, 277 (37), 34489-34498. 

Borra, M.T., Smith, B.C. and Denu, J.M. (2005) Mechanism of human SIRTl activation by resveratrol. The Journal of Biological Chemistry, 280, 17187-17195. 

Vdkaitis, G., Merkiene, E., Serva, S., Weinhold, E. and Klimasauskas, S. (2001) The mechanism of DNA cytosine-5 methylation. Kinetic and mutational dissection of Hhai methyltransferase. The Journal of Biological Chemistry,... 

Mechanism of human SIRTl activation by resveratrol. The Journal of Biological Chemistry, 280, 17187-17195. 

Most of biological chemistry can be understood in terms of simple ball and stick models. The chemistry of nitric oxide and related oxides is more intimidating because its patterns of bonding depend strongly on quantum mechanics and molecular orbital theory. But the basics can be grasped by comparison to other molecules and a simple consideration of where nitrogen sits in the periodic table. 

Messerschmidt, A., Prade, L. and Wever, R. (1997). Implications for the catalytic mechanism of the vanadium-containing enzyme chloroperoxidase from the fungus Curvularia inaequalis by X-ray structures of the native and peroxide form. Journal of Biological Chemistry, 378,309-315. 

Porter, T.D. and Coon, M.J. (1991). Cytochrome P-450. Multiplicity of isoforms, substrates, and catalytic and regulatory mechanisms. Journal of Biological Chemistry, 266, 13469-13472. 

Nucleic acids store Information for the Mechanisms In biological chemistry... 

Life runs on chemistry, and the chemical side of biology is fascinating for that reason alone. But from the point of view of a textbook, biological chemistry s combination of structures, mechanisms, new reactions, and synthesis is also an ideal revision aid. We shall treat this chemistry of living things in three chapters. 

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