In Vitro Expression And Activity Analysis Of Lysozymes From The Hydrothermal Tubeworm, Ridgeia Piscesae

Ridgeia piscesae, a giant tubeworm, inhabits the harsh hydrothermal vents of the northeast Pacific Juan de Fuca Ridge. In this study, we cloned two R. piscesae lysozymes, named Rplyso-A (26.1 KDa) and Rplyso-B (25.8 KDa). These two proteins are highly homologus and share an identity of 77.27%. Database searches and phylogenetic analysis reveal they belong to i-type lysozyme family. Strikingly, Rplyso-A and Rplyso-B have as many as 29 cysteine residues, indicating disulfide bridges may play an important role in the stability of these proteins. Furthermore, we also found both two lysozymes display lysozyme, isopeptidase and antibacterial activities. In addition, RT-PCR analysis reveals that Rplyso-A and Rplyso-B are highly expressed in the vestimentum and trophosome of R. piscesae. no transcripts in plume and opisthosome, we concluded these two lysozymes may play a complementary role in digestion.