I haven''t moved cash from Turkey to the UK via the Denizbank, but I have done it from Yapi Kredi. With that bank, I changed my lira into sterling online, then had to go into the branch with the IBAN number and account number of my UK bank account. I had to sign a form, and they charged me something for the transfer (which I think was a very small percentage of the amount I was transferring) and it was done a day later.
Unless you have a foreign currency account in the UK, I don''t think you''ll be able to transfer lira. It will have to be Sterling.