HeavyDeception

Could really use some help I have a image that's transparent on one side and opaque on the other same layer tho. but Hi I have an image that has a gradient effect on the transparency its sold on one end and kind of see through on the other. I is there anyway I can keep that effect and have the background transparent? As of right now when i try to turn it into a gif it makes the image look opaque all the way through.