Immunogen sequence: TNSTFVQALV EHVKEECDRL GPGMADICKN YISQYSEIAI QMMMHMQPKE ICALVGFCDE VKEMPMQTLV PAKVASKNVI PALELVEPIK KHEVPAKSDV YCEVCEFLVK EVTKLIDNNK TEKEILDAFD KMCSKLPKSL SEE. PSAP is a highly conserved glycoprotein which is a precursor for 4 cleavage