For the mayonnaise: Boil the corn in a small pot of salted water or microwave for 3 to 4 minutes. Cool. Cut the kernels from the cob and then run a knife along the cobs to press out the milky juices into the bowl. Discard the cob or save for making a broth.
Blend the corn kernels in the milky juices, mayonnaise, sour cream and chile, together in a mini-food processor until smooth. Season with 1/2 teaspoon salt and pepper. Set aside.
For the tomatoes: Cut the tomatoes into wedges, about 3/4-inch at the thickest, about 16 wedges per tomato.
Pour 2 to 3 inches of oil in to a medium pot and heat over medium-high heat until a deep-fry thermometer registers between 350 and 360 degrees F.
Mix together the panko and cayenne with 1 tablespoon salt in a bowl. Put the flour in another bowl, and in a third bowl pour the buttermilk. (Have a bowl of water for dipping your fingers to keep them clean while breading.)
Dredge the tomatoes wedges first in the buttermilk, then the flour, then again in the buttermilk and then finally dredge in the panko, turning as needed to make sure they are well coated. Working in batches of 4 or 5 pieces, fry the tomatoes, turning as needed, until golden brown, about 3 minutes. Transfer to paper towels and season with salt.
Serve the tomatoes with the mayonnaise and lime wedges.