Inhibition of high voltage-activated Ca2+ currents from cultured sensory neurones by a novel insect peptide.
PMP-D2, a novel 35 amino acid peptide isolated from the brain of the locust Locusta migratoria, is localised specifically in neurosecretory cells and nerve tracts of the Pars intercerebralis. When PMP-D2 is applied onto rat sensory neurones it blocks high voltage-activated inward Ca2+ currents at concentrations ranging from 0.1 mu M to 10 mu M. The inhibitory effect of PMP-D2 is more marked on the sustained inward Ca2+ current measured at the end of 100 ms voltage step commands than on the maximum inward Ca2+ current. These results suggests that PMP-D2 may differentially inhibit the two components of the high voltage-activated inward Ca2+ currents of rat sensory neurones.
School of Biological & Molecular Sciences, Oxford Brookes University, U.K.
L
L
Harding
R H
RH
Scott
C
C
Kellenberger
H
H
Hietter
B
B
Luu
D J
DJ
Beadle
I
I
Bermudez
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism; D047169:Cyclotides; D006110:Grasshoppers / Q000378:metabolism; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D007301:Insect Hormones / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D019476:Insect Proteins; D007700:Kinetics; D009419:Nerve Tissue Proteins / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D009475:Neurons, Afferent / Q000187:drug effects* / Q000378:metabolism*; D051381:Rats
D015220:Calcium Channels; D047169:Cyclotides; D007301:Insect Hormones; D019476:Insect Proteins; D009419:Nerve Tissue Proteins; C072986:PMP-D2 peptide, insect; D002118:Calcium