Molecular complexes proteins

Naturally occurring molecular ensembles such as proteins from photosyntlietic systems (plants, algae, photosyntlietic bacteria, etc) are usually relatively rigid systems tliat contain various cliromophores and hold tliem at fixed positions and orientations relative to each otlier. That is why, despite tire numerous energy jumps between tire cliromophores, tlie resulting emitted fluorescence is polarized. The extent of tliis polarization tlius affords invaluable infonnation about tlie internal stmcture of molecular complexes. 

Biosynthesis. The biosynthesis of neuropeptides is much more complex and involves the multistep process of transcription of specific mRNA from specific genes, formation of a high molecular weight protein product by translation, post-translational processing of the protein precursor to allow for... 

Structural Formula Complex protein, molecular weight 33,000 Chemical Abstracts Registry No. 9001-00-7... 

Chemical Name Complex protein, molecular weight about 75,000... 

Structural Formula Orgotein is a complex protein with a molecular weight of about 33,000. It Is a divalent metal (Mg, Cu, Zn) chelated structure. 

Capillary SDS-Sieving Electrophoresis In the presence of a sieving matrix, mobility decreases monotonically with molecular weight for SDS-complexed proteins. This relationship is the basis of SDS-PAGE separation of proteins. 

When the ligand is placed or found inside the receptor pocket, then the free energy of binding of the molecular complex is estimated computationally. Therefore the 3D-coordinates of the atoms in the protein receptor, a structural formula of the ligand, with bond lengths and angles and in addition knowledge of the position of the active site are required. 

PMF is generally used to identify proteins that have been previously separated by 2-D GE so that additional information including the molecular weights and isoelectric points can be used to supplement PMF identification. PMF is not well suited for searching expressed sequence tag (EST) databases that contain incomplete gene coding information for particular ESTs and it is not adequate for the analysis of complex protein mixtures in solution. 

There is now a growing interest in proteomic studies of brain synapses. Recent studies have revealed a high molecular complexity in the pre- and postsynaptic areas, with thousands of proteins [6]. An important investigation for the future is to identify posttranslational modifications, miscoded as well as misfolded proteins, likely to have an impact on different aspects of synaptic function as a response to the environment as well as to the lifestyle. The first challenge is to identify and quantify the presence and variation of different proteins in key structures of the pre- and postsynaptic areas in order to relate protein structures to synaptic function. Recently, a new model has been presented describing the molecular complexity of the synapse with important aspects in emotions, thinking, memory, and consciousness [7] (Fig. 17.2). 

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