A new protein-based bioadhesive material from fish parasites

Monogenoids are fish parasites which are able to quickly and reversibly attach to their host in the presence of strong water currents through the secretion of a proteic glue. The adhesive secretion is produced by glands located in the antero-lateral region of the animal. Unlike most adhesive secretions found in the animal world which stick to abiotic substrates, monogenoidean adhesive secretion works on living tissues. All these features make it a very promising material for exploitation in the surgical field. The aim of this work is the characterization of the bio-adhesive material by means of a proteomic approach. Since no genomic data for monogenoids are available, an MS/MS based de novo sequencing strategy was applied. The secreted material was obtained by electrostimulation of the parasites in a 50% PBS solution using 40 volts electric field and 2 Hz frequency. The secretion of 30 parasites was collected in a test tube and the SDS soluble and unsoluble components were analysed separately. Following to 2D-electrophoresis, each spot was trypsin digested and analysed by nano-LC-MS/MS using an LTQ Orbitrap Velos (Thermo Scientific, Germany). De novo sequence analysis and protein identification were obtained using Peaks Studio 5.3 (Bionformatics Solutions, Canada). Separate analysis of SDS soluble and unsoluble components of the glue suggests that more than 90% of the proteinaceous adhesive material is SDS unsoluble. Identification of proteins following de novo sequencing and database similarity searches using Peaks Studio allowed concluding that the glue is composed by a relatively small number of proteins, as expected for this type of material. De novo sequencing by high resolution MS/MS allowed the characterization of the proteic components of a new bioadhesive material with potential medical applications. Acknowledgments: this research was founded by grants from Fondazione CARIPLO, Milano, Italy