The Ottoman capture happend roughly at the same time as the Golden Horde, which controlled the lands north of the Black Sea, experienced extensive instability and eventually collapsed into a series of smalled Khanates, among them the Crimean Khanate (which would become an Ottoman vassal state). Trading through the territory of the Golden Horde was severely disrupted as a result. By the time the dust settled and a number of Khanates had been established in 1502, the Portuguese had already found the way around Africa and the Spanish had found America.

Can you be specific on who you mean as "traders"? Trade continued through Venetian merchants and other parties, who maintained peaceful relations with the Ottomans even though things became testy over time.