Car will not turn over. New battery, good starter. Turn key and nothing happens.

Hello; odd sounding concern, but the little clue of things changing when depressing the parking brake could lead to seeking out some kind of under dash wiring issue somewhere between the electrical ignition switch and the starter relay. Totally a guess, but in any case, will need to start from scratch with a wiring diagram trying to see what is missing from the vehicle which is causing it to not start. Good luck.