Speciation of HDL
There is considerable inferential evidence that the high density lipoproteins (HDL) of mammalian plasma should have greater structural and functional heterogeneity than has been so far established. It is likely that at least transitory progenitors of HDL originating from hepatic and intestinal cells will differ from one another, perhaps forming discrete series of particles. The diverse metabolic processes in which HDL participate in plasma are likely to require still further determinative speciation. Some speciation will no doubt reflect low free energy combination states determined by the interactive energetics and stereochemistry of their constitutive elements. However, kinetic speciation is likely to account for accumulation of some particle species, that is, in concatenated processes, intermediaries with the lowest rate constants of removal tend to accumulate. An accurate assessment of particle populations in plasma must take into account the fact that chemical processes will tend to move toward thermodynamic equilibrium after sampling, thus altering the distribution of species. Approaches to the study of lipoprotein speciation must therefore include the use of techniques which allow for the isolation of transitory or thermodynamically unstable particles and which do not introduce perturbations of structure. In the following we will discuss the plurality of roles for HDL and evidence that these lipoproteins comprise a number of discrete subpopulations.
KeywordsHigh Density Lipoprotein High Density Lipo Cholesteryl Ester Transfer Protein Plasma High Density Lipoprotein High Density Lipo
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