Yes if it is a black 10.5 Retail Upgrade DVD or white Snow Leopard Upgrade DVD (gray install disc's are system specific and will not work)
These instructions are for a new Hard Drive, but work just the same because re-partitioning and re-formatting will erase the Hard Drive, allowing you to install a clean OS X
1. Boot from your install DVD or Bootable Clone and open Disk Utility.
2. Highlight the new HD in the list of drives and select the Partition tab.
3. Under Volume Scheme select 1 Partition and click on the Options... button.
4. Select GUID Partition Table in the drop down window and click OK.
5. Set the Format to Mac OS Extended (Journaled) and click the Apply button.
6. Once thats done then you can do a clean Install, Restore from TM or a Bootable Clone.
Sorry, I misunderstood and thought that you had a Retail Leopard Upgrade DVD.
Providing that it is not stolen, the original owner is not the sharpest person for selling it without first erasing all there data. Perhaps if you were to jog there memory, they could come up with the original disc set or an upgrade DVD for you...