Small Molecules protein function

D. tRNAs are small molecules that function as adaptors to convert or translate the nucleotide sequence information of mRNAs into the amino acid sequences of the proteins they encode. 

Polarization interactions for atoms and small molecules or functional groups are much weaker than the other interactions listed above. For example, in vacuum the attractive energy between two methyl groups is only about 0.15 kcal/mol (0.6 kJ/mol) at a separation of 0.4 nm. However, polarization interactions are additive, so that for large bodies with many individual polarization interactions (e.g., a protein binding a large substrate molecule) the overall contribution may be 10 to 20 kcal/mol (40-80 kJ/mol). Furthermore, these interactions will be present for both nonpolar and polar (even ionic) groups. 

Functional protein microarrays are useful for direct analysis of biochemical activity (e.g., substrate specificity, Refs. 98 and 99), protein protein interaction (100), or small molecule protein interaction. Proteins of interest are over expressed and applied in pure form on addressable arrays, and assays performed (101). 

Biomolecules containing metals are large in number and variety. For convenience, we can divide them into three main categories nonproteins (simple and/or small molecule species), functional proteins (transporters of electrons or specific molecules or ions, or else sites serving as storage reserves of heavily used metal ions sometimes called transport and storage proteins), and enzymes (selective catalysts of specific reactions). Within these, there are further sub-divisions, as exemplified in Table 8.1. 

Figure 1 An example of how small molecular building blocks can combine with various functional ligands to form a supramolecular stractuie. A load is often incorporated within the nanoparticle to confer therapeutic or diagnostic functionality and may consist of small molecules, proteins, or nucleic acids. From these molecular building blocks, a combinatorial library of supramolecular nanoparticles with structural and functional diversity can be easily generated by varying the mixing ratio of the molecular building blocks, the functional ligands, and the loads.

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