When {HEAD ~ the pH} rises above the pI of {TAIL ~ the protein}, the protein assumes a net negative charge 
When { HEAD ~ the pH } rises above the pI of { TAIL ~ the protein } , the protein assumes a net negative charge
OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH