I tried using the install disk that came with my MP to install Leopard on my Tiger equipped MBP but it would sit there for a few seconds then eject the disc.
Under the assumption that you're still trying to install Leopard using the install disc that came with your Mac Pro, the answer is simple - you can't. The install disc for your Mac Pro was made specifically to installl on your Mac Pro, so your only choice is to purchase another copy of Leopard to install it on your MacBook Pro.