Purification, Characterization and N-terminal Sequences Alignment of a Mannose Specific Protein Purified from Potca Fish, Tetraodon patoca

Foreword to 'Multiscale structural biology: biophysical principles and mechanisms underlying the action of bio-nanomachines', a special issue in Honour of Fumio Arisaka's 70th birthday

This issue of Biophysical Reviews, titled 'Multiscale structural biology: biophysical principles and mechanisms underlying the action of bio-nanomachines', is a collection of articles dedicated in honour of Professor Fumio Arisaka's 70th birthday. Initially, working in the fields of haemocyanin and actin filament assembly, Fumio went on to publish important work on the elucidation of structural and functional aspects of T4 phage biology. As his career has transitioned levels of complexity from proteins (hemocyanin) to large protein complexes (actin) to even more massive bio-nanomachinery (phage), it is fitting that the subject of this special issue is similarly reflective of his multiscale approach to structural biology. This festschrift contains articles spanning biophysical structure and function from the bio-molecular through to the bio-nanomachine level.

Purification and characterization of a mannose recognition lectin from Oreochromis niloticus (tilapia fish): cytokine production in mice splenocytes

The aim of this work was to purify and partially characterize a mannose recognition lectin from Nile tilapia (Oreochromis niloticus) serum, named OniL. OniL was isolated through precipitation with ammonium sulfate and affinity chromatography (Concanavalin A-Sepharose 4B). In addition, we evaluated carbohydrate specificity, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) profiles, and in vitro immunomodulatory activity on mice splenocyte experimental cultures through cytotoxic assays and cytokine production. The ammonium sulfate fraction F2 showed the highest specific hemagglutinating activity (331) and was applied to affinity matrix. Adsorbed proteins (OniL) were eluted with methyl-α-D: -mannopyranoside. OniL, a 17-kDa protein by SDS-PAGE constituted by subunits of 11 and 6.6 kDa, showed highest affinity for methyl-α-D: -mannopyranoside and D: -mannose. Immunological assays, in vitro, showed that OniL did not show cytotoxicity against splenocytes, induced higher IFN-γ production and lower IL-10 as well as nitrite release. In conclusion, OniL lectin was successfully purified and showed a preferential Th1 response in mice splenocytes.

The cytotoxic activity of two D-galactose-binding lectins purified from marine invertebrates

The present investigation was undertaken in order to evaluate the cytotoxic effect of two D-galactose-binding lectins using the brine shrimp lethality bioassay technique. Both lectins were purified from the marine invertebrates, sea hare Aplysia kurodai eggs and polychaete Perineries nuntia by conventional affinity chromatography methods. The molecular mass of Aplysia kurodai egg lectin (AKL) was determined to be 32 kDa and 56 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis under reducing and non-reducing conditions, respectively. On the other hand, polychaete Perineries nuntia lectin (PnL) was determined to be 32 kDa in both reducing and non-reducing conditions. AKL and PnL showed strong agglutination activity against trypsinized and glutaraldehyde-fixed human and rabbit erythrocytes. AKL significantly affects the mortality rate of brine shrimp. Experimental results revealed that AKL was found to be more toxic (63.33% mortality) than PnL (33.33% mortality) and the mortality rate of brine shrimp nauplii was increased with the increase in concentration of lectins. These cytotoxic results indicate that future findings of lectin applications obtained from marine invertebrates may be of importance to clinical microbiology, and that they could have application as potent chemotherapeutic agents.