Ger J. van der Vusse - Böcker

During recent decades, bewildering progress has occurred in the field of Molecular and Cellular Biochemistry. Progress has been extraordinarily rapid primarily because of the challenge for finding solutions to a wide variety of diseases and the availability of new techniques for monitoring biochemical processes. This has resulted in a voluminous and complex literature in the field of biochemical medicine so that there is a clear need for the synthesis and analysis of the continuing expansion of valuable data. It was thus considered appropriate to initiate a new series of monographs, each dedicated to a specialized area of investigation, encompassing molecular and cellular processes in health and disease. Most of the biochemical scientists have devoted their energies in understanding the fundamentals of biochemistry and indeed impressive advances have been made in the past. However, the full potential for explanation has been hampered by the concept of universality of biochemical reactions occurring in the cell. In view of the fact that each organ in the body performs a distinct function, it is now beginning to be realized that each cell type is unique in its need to survive and perform its specific function. Accordingly, the aspect of individualty is receiving increased attention for revealing new avenues in the study of pathophysiology of cellular abnormalities.

The discovery of the second-messenger functions of on serine and threonine residues. Although there is inositol 1,4,5-trisphosphate (Ins(1 ,4,5)P 3) and 1,2-dia- general agreement that PKC plays an important role in cylglycerol (DAG), the products of receptor-stimulated the initiation and/or modulation of receptor-linked re- phosphatidylinositol 4,5-bisphosphate (PtdIns( 4,5)P ) 2 sponses, the precise nature or molecular details of this hydrolysis, marked a turning point in the studies on the involvement remain elusive. There are several sugges- mechanisms of mediation of functional hormone and tions of possible functions of PKC, including involve- neurotransmitter responses. The historical background ment in modulation of ionconductance, regulation of of this discovery and the extensive bibliography of the receptor interaction with components of (other) signal 2 enormously expanding knowledge in this field was re- transduction pathways, modulation of Ca + sensitivity cently presented by Rana and Hokin [1], the latter of contractile proteins and gene expression [6]. author who first observed the 'phosphoinositide' effect The receptors involved in the activation of the adeny- 35 years ago.It was, however, the Ca2+ gating hypothe- late cyclase and PtdIns cascade pathways have one com- sis proposed by Michell [2] on basis of a survey of mon feature. They are present in the plasmamembrane observations on the phosphoinositide turnover in a as complexes with GTP binding proteins (G-proteins).

The cellular functions of lipid-transport proteins cannot can be obtained, as well as structural information re- garding the local environment of the spectroscopic be fully realized without a comprehensive knowledge of probe. However, changes in protein fluorescence upon their binding properties. In particular, it is important to identify physiologically important ligands and establish ligand binding are sometimes too small to quantitate. their binding affinities, stoichiometries and specificities. This is particularly true for L-FABP, which has no tryp- Since many lipid-binding proteins exhibit no enzymatic tophan residues. Also, some lipids lack intrinsic fluores- cence or paramagnetic properties, including many lipids activity, binding parameters provide an important quan- titative measure for comparing the 'activity' of various of physiological interest. In such cases, lipid analogues wild-type and mutant forms. For this purpose, binding containing structure-perturbing anthroylxoxy or doxyl assays that are quantitative, accurate and robust are de- probes are required. Lipids that do have intrinsic fluor- sirable. escence, such as parinaric acid, are labile and prone to For the intracellular fatty acid- and lipid-binding pro- oxidation.The binding of native ligands can be moni- teins, a variety of biochemical and biophysical binding tored by isotope-directed NMR techniques, provided assays have been used. The biochemical assays include that enrichment with 13C or another suitable isotope is those based on gel-filtration [1-3], equilibrium dialysis feasible. Although such NMR methods are useful for de- [4], Lipidex [5,6] and liposomes [7].

During recent decades, bewildering progress has occurred in the field of Molecular and Cellular Biochemistry. Progress has been extraordinarily rapid primarily because of the challenge for finding solutions to a wide variety of diseases and the availability of new techniques for monitoring biochemical processes.

The cellular functions of lipid-transport proteins cannot can be obtained, as well as structural information re- garding the local environment of the spectroscopic be fully realized without a comprehensive knowledge of probe. However, changes in protein fluorescence upon their binding properties. In particular, it is important to identify physiologically important ligands and establish ligand binding are sometimes too small to quantitate. their binding affinities, stoichiometries and specificities. This is particularly true for L-FABP, which has no tryp- Since many lipid-binding proteins exhibit no enzymatic tophan residues. Also, some lipids lack intrinsic fluores- cence or paramagnetic properties, including many lipids activity, binding parameters provide an important quan- titative measure for comparing the 'activity' of various of physiological interest. In such cases, lipid analogues wild-type and mutant forms. For this purpose, binding containing structure-perturbing anthroylxoxy or doxyl assays that are quantitative, accurate and robust are de- probes are required. Lipids that do have intrinsic fluor- sirable. escence, such as parinaric acid, are labile and prone to For the intracellular fatty acid- and lipid-binding pro- oxidation.The binding of native ligands can be moni- teins, a variety of biochemical and biophysical binding tored by isotope-directed NMR techniques, provided assays have been used. The biochemical assays include that enrichment with 13C or another suitable isotope is those based on gel-filtration [1-3], equilibrium dialysis feasible. Although such NMR methods are useful for de- [4], Lipidex [5,6] and liposomes [7].

The discovery of the second-messenger functions of on serine and threonine residues. Although there is inositol 1,4,5-trisphosphate (Ins(1 ,4,5)P 3) and 1,2-dia- general agreement that PKC plays an important role in cylglycerol (DAG), the products of receptor-stimulated the initiation and/or modulation of receptor-linked re- phosphatidylinositol 4,5-bisphosphate (PtdIns( 4,5)P ) 2 sponses, the precise nature or molecular details of this hydrolysis, marked a turning point in the studies on the involvement remain elusive. There are several sugges- mechanisms of mediation of functional hormone and tions of possible functions of PKC, including involve- neurotransmitter responses. The historical background ment in modulation of ionconductance, regulation of of this discovery and the extensive bibliography of the receptor interaction with components of (other) signal 2 enormously expanding knowledge in this field was re- transduction pathways, modulation of Ca + sensitivity cently presented by Rana and Hokin [1], the latter of contractile proteins and gene expression [6]. author who first observed the 'phosphoinositide' effect The receptors involved in the activation of the adeny- 35 years ago.It was, however, the Ca2+ gating hypothe- late cyclase and PtdIns cascade pathways have one com- sis proposed by Michell [2] on basis of a survey of mon feature. They are present in the plasmamembrane observations on the phosphoinositide turnover in a as complexes with GTP binding proteins (G-proteins).