What is unusual about the membrane spanning part of the hemolysin protein, with respect to the protein folding rules for soluble proteins?

The hemolysin protein refers to a membrane protein, which spans the phospholipid bilayer. In the hemolysin protein, the membrane-spanning part comprises beta sheets rolled into a barrel configuration rather than being made up of alpha-helices.  

When folded into a beta-barrel configuration, the outside of the barrel is hydrophobic and the interior is hydrophilic. A beta barrel configuration is essential for the generation of large, trans-membrane pores via which solute can diffuse hysterically, leading to hemolysis.

explanation:

the universal gravitation equation. since the gravitational force is directly proportional to the mass of both interacting objects, more massive objects will attract each other with a greater gravitational force. if the mass of one of the objects is doubled, then the force of gravity between them is doubled.