Except the miners don't gain value from discovering a protein fit, so they have no incentive to mine the wrong chain.
Even then, as long as the coin value is larger you will have a consensus with the miners to to mine the latest block. Any sidechains will be neglected, which is why this "no value or nothing" attitude doesn't fit a blockchain network.
The PoW must only be useful for the coin you are mining and nothing rise.