Protein information content

These ordered biopolymers, which allow the combustion engine to work and to replicate itself, must also be replicated exactly once a perfect translation of substrate structure into a specific function has been established. Hence the molecular information in the proteins (enzymes) must be safely stored into stable, relatively static language. This is where the nucleic acids enter into the picture. Consequently another translation phenomenon involves protein information content written into a linear molecular language which can be copied and distributed to other cells. 

EE Abola, EC Bernstein, SH Bryant, TF Koetzle, J Weng. Protein data bank. In EH Allen, G Bergerhoff, R Sievers, eds. Crystallographic Databases Information, Content, Software Systems, Scientific Applications, Bonn Data Commission of the International Union of Crystallography, 1987, pp 107-132. 

In retrospect it is easy to see that such structural irregularity is actually required for proteins to fulfill their diverse functions. Information storage and transfer from DNA is essentially linear, and DNA molecules of very different information content can therefore have essentially the same gross structure. In contrast, proteins must recognize many thousands of different molecules in the cell by detailed three-dimensional interactions, which... 

Although anosmias to these compounds occur at similar levels, some communicative value may arise from the persistence of signal emissions which are not enantiomerically pure (Carman, 1993 Wysocki et al., 1999). In secreted mixtures, the alternate versions of such compounds are produced in a constant ratio since they have identical volatility and hence provide stable informational content to the receiver. Support for this idea comes from the results of the NMR mapping of the BT binding site within the MUP1 carrier (Zidek et al., 1999). Here the protein-ligand complex does exist in the expected ratio, and for both enantiomers, although the orientation of the bound thiazole was interpreted as opposite to that indicated by previous X-ray analyses. 

The three major classes of biopolymers found in eukaryotic systems are nucleic acids, proteins, and polysaccharides. The latter class is the most complex with respect to structural and stereochemical diversity. Polysaccharides indeed possess a massive information content. Furthermore, polysaccharides are commonly found in nature covalently attached (conjugated) to other biomolecules such as proteins, isoprenoids, fatty acids, and lipids.1... 

More recently, homonuclear correlation techniques relying on J-couplings have also been developed [86, 87, 89] and applied to the assignment of spin systems of amino-acid residues in uniformly labeled proteins and peptides [90]. These have, in some cases, a higher information content than the comparable dipolar-mediated experiments, as relayed correlations throughout the continuous 13C-13C network are more easily realized at high B0 fields [90]. 

SP TR NRDB (or abbreviated SPTR) was created to overcome these limitations. SPTR provides a comprehensive, nonredundant and up-to-date protein sequence database with a high information content. The components are ... 

Abola EE, Bernstein FC, Bryant SH, Koetzle TF,Weng J (1987) In Allen FH, Bergerhoff G, Sievers R (eds) Protein data bank in crystaUographic databases-information content, software systems, scientific applications. Data Commission of the International Union of Crystallography, Bonn Cambridge Chester, pp 107-132... 

Other excited-state effects besides coordination changes are observed in the transient Raman spectra (10,11). Further analysis of the excited states and dynamics of Ni-porphyrin complexes and Ni-reconstituted heme proteins should benefit from Raman spectroscopy s inherently rich structural information content. Transient Raman methods are now being applied to other metalloporphyrins and metalloporphyrin-based systems. 

Transcription of genes in mammals often initially produces a pre-mRNA, whose information content can be modulated by subsequent polyadenylation or splicing. Various final mRNAs coding for proteins with varying fimction and localization can be produced in this manner starting from a single primary transcript. 

The transport from nucleus to cytoplasm is accompanied by modification at the 5 - and 3 -end of the pre-RNA, as well as by processing (splicing) of the primary transcript. The 3 -end modifications and sphcing decide which information contained in the primary transcript is made available for protein biosynthesis. The information content of the processed mRNA can be specifically influenced by these processes. This has an important impact on the tissue- and cell-specific protein expression. 3 -modification and splicing are tightly coupled to extranuclear transport. Interventions in the transport process are another possibihty for a regulation at the post-transcriptional level. 

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