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Camel antibodies for PSA assays
hPSA
They are part of a team that has already in bacteria. Back then, these tasks could Camel antibodies are cool. That’s what be difficult, so an antibody that had only reported that VHHs raised against huSerge Muyldermans and others, working man lysozyme can inhibit the aggregaone type of fragment was interesting. in the laboratory of Raymond Hamers at tion of the amyloidogenic variant of the Hamers’s group called the single-dothe Vrije Universiteit Brussel (Belgium) protein (Nature 2003, 424, 783–788). main antigen-binding fragment VHH, and Trinity College Dublin (Ireland), disFor the hPSA studies, the researchers to distinguish it from the variable heavy covered years ago (Nature 1993, 363, evaluated two types of conventional chain of conventional antibodies, known 446–448). Antibodies from camel serum probes—a monoclonal antibody and its as VH. are unusually small and quite stable and single-chain variable bind to epitopes that are (c) (b) hPSAfree hPSAfree fragment (scFv) derivarelatively inaccessible to cAbPSA-N7-Fc cAbPSA-N50-Fc tive—and a VHH probe. conventional antibodies. In this issue of Analytical hPSAtotal Various immobilization strategies were tested. Chemistry (pp 7547– In the SPR assays, the 7555), researchers at the hPSA ACT hPSA (a) hPSAfree VHH probe performed Flanders Interuniversity significantly better (LOD Institute for Biotechnol= 0.190 ± 0.003 ng/ ogy (Belgium), including cAbPSA-N50 cAbPSA-N7 mL) than the other two Muyldermans, explain why these antibodies Schematic of a sandwich assay for detecting hPSAfree and hPSAtotal. (a) hPSA free is (LOD = 0.450 ± 0.005 ng/mL for the scFV make good biosensor detected directly or (b) enhanced by the cAbPSA-N7-Fc construct. (c) hPSA total is construct and 0.500 ± probes and describe a detected as hPSA free plus hPSA in a complex with 1-antichymotrypsin (ACT). 0.003 ng/mL for the surface plasmon resomonoclonal antibody). Further study revealed other interestnance (SPR)-based assay for human In the ELISAs, the monoclonal antiing properties, says Muyldermans. VHHs prostate-specific antigen (hPSA) that can body, which is larger than the VHH and are very stable because they “lack a syndetect clinically relevant concentrations of the scFv derivative, actually performed thetic linker, and they are monomeric,”
