No. At least, not in double precision. The "exact" value there is impossible to represent in a double precision number.
The normal pdf at z = -77 should be:
p = exp(-(x-mu).^2/sig^2/2)*1/(sig*sqrt(2*sym('pi')))
Do you understand this is a number with around 1288 zeros after the decimal point, before you see any digits?
As such, the result underflows in double precision. You get ZERO.
Actually, you can go about as far as -38 or so, before an underflow occurs, with the result as what is known as a denormalized number. But that is around the limit. And even most computations with those numbers at that level will still yield numerical garbage.
You can want what you want, but this is not possible working in double precision. If you are willing to use higher precision tools, such as syms, then yes, you can.