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