A NOVEL ENZYME-LINKED-IMMUNOSORBENT-ASSAY FOR DETERMINATION OF SYNAPTOPHYSIN AS COMPARED WITH OTHER QUANTIFICATION PROCEDURES

A two-sided enzyme-linked immunosorbent assay (ELISA) has been establi shed for reliable, specific and sensitive determination of synaptophys in (SYN), an intrinsic membrane protein of the small synaptic vesicles . This ELISA used a highly specific monoclonal antibody (SY 38) as cap ture reagent and a specific SYN antiserum in combination with a second ary peroxidase-conjugated antibody for detection. Calibration was carr ied out with immunoaffinity-purified SYN from porcine cortex. The sens itivity was found to be improved substantially when the ELISA was comp ared with previously used dot-immunobinding assays. This ELISA allowed rapid and reliable determination of SYN from detergent lysed homogena tes, partially and highly purified preparations of rat, porcine and hu man brain. SYN was determined in highly purified small synaptic vesicl es, and it was calculated to be 5.8% of total detergent solubilized pr otein.