El análisis de control de flujo como herramienta en la manipulación de vías metabólicas

摘要: Flux control analysis of a metabolic pathway allows the quantitative determination degree that given enzyme (Ei) exerts on flux J (i.e., coefficient Ei C ) and concentration metabolites M ), thus substituting misleading, qualitative concept rate limiting steps in pathways. In addition, it helps to understand (i) underlying reasons by which high or low (ii) why does not reside only one (“the step”); instead, is shared several enzymes transporters. Several different experimental approaches have been developed for . For instance, titration with specific inhibitors has used oxidative phosphorylation isolated mitochondria intact cells. Elasticity perhaps most profusely approach many pathways, mainly glycolysis. This consists sensitivity (or block enzymes) towards variation its substrates products, under steady-state conditions pathway. If activity significantly change ligands (low elasticity, e then enzyme, transporter close Flores Herrera O, Rendon Huerta E, Riveros Rosas H, Sosa Peinado A, Vazquez Contreras Velazquez Lopez I (eds). Mensaje Bioquimico, Vol XXIX. Depto Bioquimica, Fac Medicina, Universidad Nacional Autonoma de Mexico. Cd Universitaria, Mexico, DF, MEXICO. (2005). (http://bq.unam.mx/mensajebioquimico) (ISSN-0188-137X) MENSAJE BIOQUIMICO, Vol. XXIX (2005) 182 saturation and, therefore, this step limits (high ). Thus, there an inverse relationship between elasticity coefficients coefficients. A third based classical genetics, much less due methodological complexity. selective vivo expression measuring effect flux, without altering other activities. Still, another recent development mathematical modeling pathways (“in silico Biology”), kinetic properties transporters experimentally obtained from both purified proteins those contained cellular extracts, addition use appropriate software data integration. One last vitro reconstitution using commercially available recombinant enzymes, near-physiological conditions. Notwithstanding available, main goal establish exert significant control, do not, when working variety relevant such as exposure temperatures, variations pH values poisons stress, hormonal status pathological states diseases. It should be noted once distribution established, possible identify modified achieve successful alteration biotechnological clinical metabolite (essential amino acids lipids, vitamins, antibiotics, glutathione). As soon controlling are identified, feasible, convenient, determine biochemical, genetic mechanisms involved exerted respective steps. To end, required but also physiological activators inhibitors. Moreover, these steps, their sub-cellular location intracellular concentration. When all information generated, highly probable manipulation may attained. Perhaps, lack type information, reluctance considered simple ignorance, led multitude unsuccessful attempts manipulate following ill-conceptualized “rate-limiting step” typical “trial-and error” over-expressing through Molecular Biology tools drug-design studies Pharmacology. exception might over-production Corynebacterium glutamicum. On hand, up date few examples chemical means supported analysis: modulation energy metabolism tumor cells yeast order diminish elevated cell proliferation enhancing ethanol production, respectively. Strikingly, some allowed identification altered states, so.