this asymmetric organization is preferentially maintained through complex , and at present , poorly understood noncovalent interactions between specific membrane lipids and proteins ( in particular , a stabilizing role for the skeletal protein spectrin and band 4.1 have been implicated ) , although other considerations such as phospholipid net charge , size , and degree of acyl chain unsaturation may also be involved .
C0025249
membrane
C0031676
phospholipid