Complete sequence and characterization of the major sperm nuclear basic protein from <i>Mytilus trossulus</i>

Abstract

We have characterized the major protamine-like protein (PL-III) from the sperm of the mussel Mytilus trossulus. The molecular mass of the main protein component of PL-III, determined by mass spectrometry using fast atom bombardment and matrix-assisted laser desorption ionization was 11304 +/- 6 Da. The complete protein sequence was established by Edman degradation and the molecular mass derived from this sequence coincides with that experimentally determined. The protein has a sedimentation coefficient s20,w = 1.15 +/- 0.5 S which is consistent with a random coil of radius of gyration 34.3 +/- 1.4 A.