Intramers and Aptamers: Applications in Protein-Function Analyses and Potential for Drug Screening

During the past decade, the complete genomes of more than 140 different organisms have been sequenced and made available in databases. These databases provide extremely useful collections of organised, validated data, which are indispensable for genomics and proteomics research and the drugdiscovery process. Differential analyses of pathogenic and healthy states of organisms and/or isolated cells provide a picture of genes and gene products that are related to, or actually responsible for, defined diseases. The challenge today is to understand in detail the function and interplay of the numerous proteins in different organisms, tissues, cell types and conglomerate protein complexes. Among the most effective ways to study the function of a given protein in the context of the living cell or organism is the application of a small-molecule drug that exhibits high specificity, affinity and inhibitory activity for the protein under investigation. However, because such inhibitors are available only for a minority of the estimated total number of proteins of higher vertebrate organisms, protein function is most commonly studied by loss-of-function phenotypic analysis.