ABSTRACT
Sperm-activating peptides (SAPs) containing novel brominated amino acids, o-bromophenylalanine and bromohistidine, and methioninesulfoxide were isolated from the egg jelly of sea urchins Tripneustes gratilla, Clypeaster japonicus and Heterocentrotus mammillatus, respectively, and analyzed by fast atom bombardment (FAB) mass spectrometry. The brominated SAPs showed the same respiratory stimulation activity toward spermatozoa of the respective species as nonbrominated SAPs, although a SAP containing methioninesulfoxide was a less potent stimulator for sperm respiration than other SAPs. In addition, complete primary structures of two SAP-I derivatives were determined by FAB mass spectrometry.
