(University of Puerto Rico Medical Sciences Campus, 1984-09)
Zuazaga, Conchita; Steinacker, Antoinette; del Castillo, Jose
The chemical reactions of sulfhydryl and
disulfide groups in proteins are discussed and the use
of reagents specific for these groups as a tool in electrophysiology is reviewed. The drastic and specific
changes seen when these group-specific reagents are
used demonstrate the critical role of sulfhydryl and disulfide groups in electrical excitability, synaptic transmission and, particularly, postsynaptic receptor function. Sulfhydryl groups have been shown to be involved in the slow inactivation process of the voltage-dependent sodium channel, in the activation of
voltage-dependent calcium channels and in sodium
channel conductance. Sulfhydryl and disulfide groups
have been shown to Intervene in the function of the
acetylcholine receptor at the vertebrate neuromuscular
junction and in invertebrate glutaminergic recepton.
The release of neurotransmitter from the presynaptic
termInals of these neuromuscular junctions Is
also sensitive to sulfhydryl and disulfide group modification.
Although in most instances the site of action
of the reagents has not been resolved, their use has produced a clearer picture of receptor and channel
structure-function relationships.
