KSAYMRFAMIDE (PF3 AF8) IS PRESENT IN THE FREE-LIVING NEMATODE, CAENORHABDITIS-ELEGANS/

To date, seven FMRFamide-related peptides (FaRPs) have been structural ly characterized from C. elegans, of which one is structurally identic al to the parasitic nematode peptide AF2 (KHEYLRFamide). The other six FaRPs have so far been identified in free-living forms only. in the p resent study an additional FaRP was isolated and structurally characte rized from an ethanolic extract of C. elegans. The extract was screene d using a C-terminally directed FaRP antiserum, and the FMRFamide-immu noreactive peptide purified to homogeneity using HPLC. Approximately 8 0 pmol of the peptide was subjected to Edman degradation and the unequ ivocal primary structure of the K-7-amide, KSAYMRFamide (PF3/AF8) was determined following a single gas-phase sequencing run. The molecular mass of the peptide was determined using a MALDI-TOF mass spectrometer and was found to be 919 (MH+), which is in agreement with the theoret ical mass of C-terminally amidated PF3. A new flp-gene, designated flp -6, has recently been identified which encodes six copies of KSAYMRFam ide (PF3/AF8). (C) 1998 Academic Press.