Not really a snap to grid type function. There are of course node alignment tools to get things in the same horizontal or vertical plane. Then you can use either the Shift or the Ctrl key + the numbers 8, 4, 6 and 2 for Up, Left, Right and Down. Those move a specific amount with each click, so you can sort of snap based on a pre-set distance vs. trying to do it manually while dragging a node.