I've read somewhere that typical C. elegans neuron has only about 50-200 ion channels distributed over the whole nervous cell. If there are so many types of channels, does it mean that each type of channel in each cell has a very small count?
Or it means that each cell has not so much different types of channes
This estimate is quite reasonable taking into accont the surface of a typical neuron (with axon / dendrites) and the size of a typical ion channel. Because cell membrane also contains other built-into-membrane proteins, as well as ion pumps / exchangers.
According to what I know about ion channels, if we have a sequence of unknown channel and its close homolog of known channel with PDB structure, than we can try to replace amino acids in PDB to our sequence of interest and then tune the new structure with MD and thus get a new model of the channel