NATALELLO ANTONINO

Scientific interests

-Protein stability, aggregation, interactions. Major research topics: protein stability; amyloid aggregation; structure-function relation; aggregation of recombinant proteins; protein-protein and protein-ligand interactions; nano- and bio-materials.

-Bioanalytical applications of spectroscopic methods. Major research topics: FTIR (micro)spectroscopy of complex biological systems; in situ studies of biological processes; spectroscopic markers.

These topics are investigated by several biophysical approaches, among them: infrared spectroscopy and microspectroscopy (FTIR and microFTIR), fluorescence and circular dichroism (CD) spectroscopies, “Native” mass spectrometry, Isothermal Titration Calorimetry (ITC), and Surface Plasmon Resonance (SPR) spectroscopy. In particular, we have investigated several aspects of protein aggregation processes also considering their biomedical and biotechnological implications, as the in vivo formation of inclusion bodies in bacterial cells and the investigation of amyloid formation in vitro and in situ. Great experience has been acquired in this field thanks to the analysis of several proteins and peptides in vitro and in complex biological systems (such as intact cells and human tissues). In the framework of the Cariplo Foundation granted project “Structure-function relation of amyloid”, we developed an isotope edited FTIR approach to investigate the role of mutations and of a molecular chaperone on the misfolding and co-aggregation of human β-2 microglobulin variants. This approach allowed studying simultaneously the conformational properties of the isotopically labelled (13C) and unlabelled protein (12C) variants (at the same time) when co-present in the same sample. In particular, the sequence of events occurring during the co-polymerization of the D76N variant and wild type β-2 microglobulin and the effect of the chaperon crystallin in the aggregation process were characterized (Natalello et al. 2016 J. Biol. Chem. 291, 9678-9689, in collaboration with Prof. V. Bellotti, University of Pavia).The role of glutamine (Q) side chains in the two aggregation stages of the poly-Q protein Ataxin-3 was also studied by biophysical approaches. In particular, by H/D exchange experiments we showed for the first time that an IR marker band can be ascribed to glutamine side-chain hydrogen bonding (Natalello et al. 2011, PLoS One. 6:e18789). This IR marker band was employed in several subsequent publications to monitor the formation of mature poly-Q aggregates in vitro and in ex vivo protein samples (in collaboration with Prof. M.E. Regonesi, UniMiB).

 

In situ studies of amyloid deposits and the comparison of ex vivo and in vitro fibrils have been also performed in different systems, including pathogenic immunoglobulin light chains derived from patients (see “Ami et al. 2016 Sci Rep. 6:29096” and “Ami et al. 2019 Anal. Chem. 91, 2894–2900”). In particular, FTIR spectroscopy is a label-free and non-invasive approach that we apply not only to isolated biomolecules but also to intact cells and tissues. In our studies, we combine IR spectroscopy with multivariate analysis to obtain a “spectroscopic fingerprinting” of the sample under investigation, which represents a snapshot of the composition and structure of its main biomolecules. For instance, we applied this approach to fat aspirates from patients affected by systemic amyloidosis (Ami et al. 2019 Anal. Chem. 91, 2894–2900) and to tears from patients affected by amyotrophic lateral sclerosis (Ami et al. 2021 Anal. Chem. 93, 51, 16995–17002). In both systems, we found that our approach differentiates the samples from the diseased individuals from control specimens with high sensitivity and specificity. It is worth noting that the wavenumbers most important for discrimination allowed us to disclose spectroscopic markers related to the pathological molecular mechanisms.

 

 

Team

Ami Diletta – PostDoc Fellow
room 4051/4050, IV floor , building U3
tel: +39 02 6448 3461/3459
[email protected]