Changing tires

I only have an MTB with 27.5 x 2.10 off-road tires that I use for commuting. If I switch to 27.5 x 1.35 road tires, will it reduce the bike's weight? If so, by approximately how much? I'm aiming for a smoother ride on the road, but I can't afford a road bike since I'm a broke high school student from Indonesia.