Fumimycin, an unusual metabolite incorporating an unusual alanine unit linked to a phenyl group at the alpha-carbon with both lactone and amide moieties, was isolated from cultures of Aspergillus fumisynnematus. Its structure was established by spectral analysis. Fumimycin was found to inhibit Staphylococcus aureus peptide deformylase with an IC50 value of 4.1 microM and also showed antibacterial activity against S. aureus.

We expressed a C-terminal 108-aa region of the Plasmodium vivax merozoite surface protein 1 (PvMSP1c) excluding the C-end transmembrane region in Escherichia coli in order to evaluate the antibody level to MSP in Korean malaria patients. We optimized a direct sandwich enzyme-linked immunosorbent assay (ELISA) method to simultaneously determine the total antibody levels, including IgG and IgM, to PvMSP1c. If the cut-off for seropositivity was determined as the mean+3SD of the antibody levels of the negative control group, the antibody levels were positive in 99.5% of the patient group (sensitivity 199/200). The antibody levels were negative in 99.4% of the negative control group (specificity 504/507). The positive reactions in the negative control group came from non-specific reactions, as confirmed by a competition assay. This direct sandwich ELISA for PvMSP1c antibody could prove to be a useful tool for the diagnosis of malaria patients and for blood screening in blood banks.

An enzyme immunoassay using eluates was developed for the quantitation of granulocyte antibodies in sera. Incubation of donor granulocytes with sera containing granulocyte alloantibodies (NA1, NA2, NB1, 5b, HLA) or autoantibodies resulted in a significantly higher amount of immunoglobulin G (IgG) per cell than did incubation with control sera. Ultracentrifugation of the sera prior to testing reduced unspecific binding of IgG to granulocytes. In eight of 10 assessed sera from patients with Felty's syndrome eluted IgG decreased from elevated to normal levels. Ultracentrifugation further allowed determination of the binding sites of granulocyte-reactive alloantibodies. Using sera containing NA1- and NA2-specific alloantibodies 173,000-188,000 binding sites on homozygous and 84,000-110,000 on heterozygous cells were determined. A similar number was found using a Fc gamma receptor III (FcRIII)-specific monoclonal antibody. Granulocytes from patients with paroxysmal nocturnal haemoglobinuria showed greatly reduced binding sites for NA-specific alloantibodies. The binding sites for the human alloantibody NB1 ranged from 36,000 to 318,000 and for the 5b alloantibody from 44,000 to 65,000. Mean values of 139,000 binding sites for HLA antigens and 27,000 binding sites for the FcRII were determined using monoclonal antibodies.

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