AIM: To construct synthetic antigens using the epitope of human brain acetylcholinesterase (hbAChE) for induction and detection of the specific antibody against the epitope, and to analyse the immunogenicity of the antibody. METHODS: The epitope (RTVLVSMNYR, amino acids 143-152) of hbAChE was chemically synthesized, coupled with the carrier protein keyhole limpet hemocyanin (KLH) to construct an artificial immunogen (KLH-epitope), and injected into rabbits to raise antibody. The epitope conjugated with bovine serum albumin (BSA) was used as the detection antigen. The specificity of the antibody was tested by enzyme-linked immunosorbent assay (ELISA) and Western blotting. The immunoreaction between the anti-recombinant human butyrylcholinesterase (rhBChE) polyclonal antibody and the biotinylated-epitope was examined by indirect ELISA. RESULTS: The erythrocyte AChE, the hbAChE, rhBChE and the BSA-epitope all immunoreacted with the anti-epitope antibody against the epitope (143-152) of hbAChE, whereas the torpedo AChE did not. CONCLUSION: The hbAChE, the human erythrocyte AChE and hBChE share the conservative antigenic epitope RTVLVSMNYR, hence they can all immunoreact with the anti-epitope antibody. Since the epitope of hbAChE is less similar with the aligned amino acid sequences of AChE of Torpedo californica or Torpedo marmorata, there is not any immunoreactivity between them. The R, M, and N residues in the epitope seem to be necessary radicals for the conservation of antigenicity.

Solid-phase synthetic method of muramyl dipeptide derivatives is reported. A diverse library of muramyl dipeptides could be potentially synthesized by acylation, reductive alkylation, sulfonamide formation, urea formation, N-alkylation, amine addition, or component Ugi reactions based on this method for drug screening.

As a non-specific modulator of macrophage, multiplied muramyl dipeptide (MMD) is solid-phase synthesized by application of standard Fmoc chemistry strategy. Tam's multiple antigen system (MAS) is used as our four branched-linker on Lysine.

A new conformationally restricted cyclic analogue of muramyl dipeptide was designed and manually synthesized by our "Meshed-Bag Gathered-Bunch" method with a combination of Fmoc, allyl and N-1-(4,4-dimethyl-2,6-dioxocyclo-hexylidene)ethyl chemical protection strategy.

In this report we demonstrate that a 1,5-dialkylamino-2,4-dinitrobenzene small molecule library can be generated by a highly efficient solution-phase synthesis method. From this 2485-member library, a series of novel compounds with antibacterial activity were isolated. The significance of this report is that the synthetic scheme is extremely simple, with minimal number of liquid handling steps, and the solvents and reagents left in the final library preparation are fully compatible with cell-based assays.