Can I get a PR erased by Google ?

Hey

I am buying a domain which is 10 years old and has a pr of 5 but I will be placing up different content up as it had before (since the domain and the topic are not directtly relevant).

How risky are my chances to lose this PR , since the PR is what gives me the golden ticket to rank it up faster on certain keywords for the new page !

Any advises ?


Thanks...