In this issue: Proteomics – Clinical Applications 10/2008

In this issue of Proteomics – Clinical Applications you will find the following highlighted articles: Build‐in‐place arrays simplify screening cast of thousands Cecil B. deMille would probably have sacrificed a significant piece of his anatomy for a simple, effective way of screening and instructing the thousands of extras needed for the battle‐ and mob scenes his movies were famous for. Ramachandran et al. put together a similar number of bodies, required for studies of the humoral immune response, on a micro scale. Protein microarrays were produced by first spotting purified, plasmid‐cloned, GST‐tagged DNA, transcribing it with T7 RNA polymerase, then translating it with a reticulocyte lysate. The full length protein was captured by anti‐GST antibody spotted on the plate or tray with the DNA. The expressed protein could then be detected by ELISA or rearrayed by pin printing for other immunodetection techniques. The programmable array was useful for auto‐antibody studies of diabetes, target antigens in potential vaccines, P53 in breast cancer and multiplex antigen tests. Ramachandran, N. et al., Proteomics Clin. Appl. 2008, 2 , 1518–1527. Protective antigen projection: analysis of vaccinia micro protein array Smallpox was officially declared eradicated in 1980. No vaccinations have been administered in the US since 1971. That did not mean there wasn't viable virus left. The US and several other countries retained viable samples “just in case.” The same countries also held small amounts of the vaccine Dryvax. With the new awareness of potential terrorist activities and the frequent adverse side effects of Dryvax, consideration is being given to the design of a new vaccine. Schmid et al. developed a method for construction of a protein microarray similar to that of Ramachandran et al. (see above) but optimized for vaccinia (251/273 genes cloned, 212 bacmid clones expressed). Hyper immune human serum bound only nine proteins, one of which appeared nonspecific. Three others correlated with virus neutralization titers and may qualify as vaccine targets. Schmid, K. et al., Proteomics Clin. Appl. 2008, 2 , 1528–1538. Alzheimer amyloids hide in detergent‐sensitive den Levels of cerebrospinal fluid amyloid beta peptides (CSF Aβ1–38, −40, and −42) are associated with a number of dementias including Alzheimer's disease (AD) and frontotemporal dementia (FTD). The peptides are the product of proteolysis of the amyloid precursor protein. Clinically, AD and FTD are difficult to distinguish. At the histological level, they can be separated by the neuritic plaques formed from Aβ peptides in AD brains, very rare in FTD cases. In searching for biomarker possibilities, Bibl et al. noted that Aβ1–42 levels were consistently low in AD cases. When they examined levels more closely using electrochemiluminescence, ELISA and SDS‐PAGE/immunoblot (SPi), they observed that levels of all three Aβ peptides were higher with SPi detection, possibly due to the existence of a detergent‐accessible pool of peptides and accuracy markedly improved with fresh (not frozen) samples. Plenty of room to explore… Bibl, M. et al., Proteomics Clin. Appl. 2008, 2 , 1548–1556.