I know that there are two components that have been accepted as having an affect on membrane fluidity: saturated/unsaturated fatty acids and cholesterol. Since proteins are another component that makes up the membrane, I was just wondering if there is any literature on how proteins affect membrane fluidity. I can't seem to find any regarding this at all. The only books/papers I've read have been on how proteins just regulate what goes in and out, but they must interact in some way with the phospholipids/cholesterol right? I would imagine that if the membrane has more proteins lodged in between it, the proteins would decrease membrane fluidity because the phospholipids would be bumping into the proteins as they move laterally. Please contribute!!! Your thoughts are much appreciated.