Dependence of Control Coefficient Distribution on the Boundaries of a Metabolic System: A Generalized Analysis of the Effects of Additional Input and Output reactions to a Linear Pathway Export

@article{citeulike:2367200, abstract = {Both experimental and theoretical studies of metabolism are likely to relate to a segment that has been isolated for analytical purposes. In practice, it will be embedded in the whole of cellular metabolism. Thus, it is necessary to consider how conclusions about the control of an isolated pathway may be modified in this wider context where the input and output metabolites are considered as variables of cellular metabolism. Here, we analyse the effect of expanding a linear metabolic pathway by adding an extra input or an extra output. In particular, we analyse the effect of the elasticities of the extra steps on control coefficients. We derive matrix algebraic relationships for obtaining flux and concentration control coefficients from expressions depending on these extra elasticities and on parameters (elasticities and control coefficients) of the original pathway. These equations can be shown in certain cases to be generalized versions of earlier rescaling relationships and to be related to top-down analysis, but also apply where the new variable metabolite of the expanded pathway is an effector of more than one step of the original pathway. We use our relationships to analyse the dependence or independence of control coefficients upon these extra elasticities for the published analyses of the pathway of mammalian serine biosynthesis (Fell \& Snell, 1988) andEscherischia coli threonine biosynthesis (Chassagnole et al., 2001). The same analysis can be applied to determine whether the transport reactions of substrates and products of a pathway in and out of a cell need to be included in estimations of the control coefficients of the enzymes.}, author = {de Atauri, P. and Fell, D. A. and Chassagnole, C. and Magret, D. and Mazat, J. P. and Cascante, M.}, citeulike-article-id = {2367200}, citeulike-linkout-0 = {http://dx.doi.org/10.1006/jtbi.2001.2492}, citeulike-linkout-1 = {http://www.sciencedirect.com/science/article/B6WMD-461K6SD-8/2/13321ebb37b1e177b40e5039910e24df}, day = {21}, doi = {10.1006/jtbi.2001.2492}, journal = {Journal of Theoretical Biology}, keywords = {analysis, boundaries, coefficient, control, distribution, generalised, linear, metabolic, pathway, system}, month = {March}, number = {2}, pages = {239--251}, posted-at = {2008-02-12 21:29:11}, priority = {2}, title = {Dependence of Control Coefficient Distribution on the Boundaries of a Metabolic System: A Generalized Analysis of the Effects of Additional Input and Output reactions to a Linear Pathway}, url = {http://dx.doi.org/10.1006/jtbi.2001.2492}, volume = {215}, year = {2002} }

TY - JOUR ID - citeulike:2367200 L3 - citeulike-article-id:2367200 N2 - Both experimental and theoretical studies of metabolism are likely to relate to a segment that has been isolated for analytical purposes. In practice, it will be embedded in the whole of cellular metabolism. Thus, it is necessary to consider how conclusions about the control of an isolated pathway may be modified in this wider context where the input and output metabolites are considered as variables of cellular metabolism. Here, we analyse the effect of expanding a linear metabolic pathway by adding an extra input or an extra output. In particular, we analyse the effect of the elasticities of the extra steps on control coefficients. We derive matrix algebraic relationships for obtaining flux and concentration control coefficients from expressions depending on these extra elasticities and on parameters (elasticities and control coefficients) of the original pathway. These equations can be shown in certain cases to be generalized versions of earlier rescaling relationships and to be related to top-down analysis, but also apply where the new variable metabolite of the expanded pathway is an effector of more than one step of the original pathway. We use our relationships to analyse the dependence or independence of control coefficients upon these extra elasticities for the published analyses of the pathway of mammalian serine biosynthesis (Fell & Snell, 1988) andEscherischia coli threonine biosynthesis (Chassagnole et al., 2001). The same analysis can be applied to determine whether the transport reactions of substrates and products of a pathway in and out of a cell need to be included in estimations of the control coefficients of the enzymes. IS - 2 JF - Journal of Theoretical Biology EP - 251 TI - Dependence of Control Coefficient Distribution on the Boundaries of a Metabolic System: A Generalized Analysis of the Effects of Additional Input and Output reactions to a Linear Pathway VL - 215 SP - 239 KW - analysis KW - boundaries KW - coefficient KW - control KW - distribution KW - generalised KW - linear KW - metabolic KW - pathway KW - system AU - de Atauri, P AU - Fell, DA AU - Chassagnole, C AU - Magret, D AU - Mazat, JP AU - Cascante, M PY - 2002/03/21/ UR - http://dx.doi.org/10.1006/jtbi.2001.2492 ER -