No, a regular database can't do that "with PKI", you have to write ledger software on top of it and you have to have one party operating the software.

cryptocurrencies are the ledger software, API, and data store layer -- and you do need trust between peers because the JPMorgan will take actions to reverse transactions if there are problems that need fixing.

It's not magical, but it is convenient for the actual ledger actions to be mathematically proven instead of the result of accounting rules in code.