García-Risco, MarioCalatayud, SaraPedrini-Martha, VeronikaAlbalat Rodríguez, RicardDallinger, ReinhardPalacios, ÒscarCapdevila Vidal, Mercè2022-02-252022-02-252021-12-041661-6596https://hdl.handle.net/2445/183539Metallothioneins' (MTs) biological function has been a matter of debate since their discovery. The importance to categorize these cysteine-rich proteins with high coordinating capacity into a specific group led to numerous classification proposals. We proposed a classification based on their metal-binding abilities, gradually sorting them from those with high selectivity towards Zn/Cd to those that are Cu-specific. However, the study of the NpeMT1 and NpeMT2isoforms of Nerita peloronta, has put a new perspective on this classification. N. peloronta has been chosen as a representative mollusk to elucidate the metal-binding abilities of Neritimorpha MTs, an order without any MTs characterized recently. Both isoforms have been recombinantly synthesized in cultures supplemented with ZnII, CdII, or CuII, and the purified metal-MT complexes have been thoroughly characterized by spectroscopic and spectrometric methods, leading to results that confirmed that Neritimorpha share Cd-selective MTs with Caenogastropoda and Heterobranchia, solving a so far unresolved question. NpeMTs show high coordinating preferences towards divalent metal ions, although one of them (NpeMT1) shares features with the so-called genuine Zn-thioneins, while the other (NpeMT2) exhibits a higher preference for Cd. The dissimilarities between the two isoforms let a window open to a new proposal of chemical MT classification.14 p.application/pdfengcc-by (c) García-Risco, Mario et al., 2021https://creativecommons.org/licenses/by/4.0/GastròpodesCisteïnaGastropodsCysteineinfo:eu-repo/semantics/article7191202022-02-25info:eu-repo/semantics/openAccess