choline(out) + H(+)(out) => choline(in) + H(+)(in)
choline(out) + h(+)(out) => choline(in) + h(+)(in)
choline(out) + H(+)(out) => choline(in) + H(+)(in)
choline(out) + h(+)(out) => choline(in) + h(+)(in)