Affinity reagent resources for human proteome detection: initiatives and perspectives

Essential to the ambition of characterising fully the human proteome are systematic and comprehensive collections of specific affinity reagents directed against all human proteins, including splice variants and modifications. Although a large number of affinity reagents are available commercially, their quality is often questionable and only a fraction of the proteome is covered. In order for more targets to be examined, there is a need for broad availability of panels of affinity reagents, including binders against proteins of unknown functions. The most familiar affinity reagents are antibodies and their fragments, but engineered forms of protein scaffolds and nucleic acid aptamers with similar diversity and binding properties are becoming viable alternatives. Recent initiatives in Europe and the USA have been established to improve both the availability and quality of reagents for affinity proteomics, with the ultimate aim of creating standardised collections of well-validated binding molecules for proteome analysis. As well as coordinating affinity reagent production through existing resources and technology providers, these projects aim to benchmark key molecular entities, tools, and applications, and establish the bioinformatics framework and databases needed. The benefits of such reagent resources will be seen in basic research, medicine and the biotechnology and pharmaceutical industries.