Giulia Tedeschi1, Edoardo Salladini2, Carlo Santambrogio1, Rita Grandori1, Sonia Longhi3, Stefania Brocca4. 1. Department of Biotechnology and Biosciences, State University of Milano-Bicocca, Piazza della Scienza 2, Milano 20126, Italy. 2. CNRS, Aix Marseille Univ, Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Marseille 13288, France. 3. CNRS, Aix Marseille Univ, Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Marseille 13288, France. Electronic address: sonia.longhi@afmb.univ-mrs.fr. 4. Department of Biotechnology and Biosciences, State University of Milano-Bicocca, Piazza della Scienza 2, Milano 20126, Italy. Electronic address: stefania.brocca@unimib.it.
Abstract
BACKGROUND: Recent theoretical and computational studies have shown that the charge content and, most importantly, the linear distribution of opposite charges are major determinants of conformational properties of intrinsically disordered proteins (IDPs). Charge segregation in a sequence can be measured through κ, which represents a normalized measure of charge asymmetry. A strong inverse correlation between κ and radius of gyration has been previously demonstrated for two independent sets of permutated IDP sequences. METHODS: We used two well-characterized IDPs, namely measles virus NTAIL and Hendra virus PNT4, sharing a very similar fraction of charged residues and net charge per residue, but differing in proline (Pro) content. For each protein, we have rationally designed a low- and a high-κ variant endowed with the highest and the lowest κ values compatible with their natural amino acid composition. Then, the conformational properties of wild-type and κ-variants have been assessed by biochemical and biophysical techniques. RESULTS: We confirmed a direct correlation between κ and protein compaction. The analysis of our original data along with those available from the literature suggests that Pro content may affects the responsiveness to charge clustering. CONCLUSIONS: Charge clustering promotes IDP compaction, but the extent of its effects depends on the sequence context. Proline residues seem to play a role contrasting compaction. GENERAL SIGNIFICANCE: These results contribute to the identification of sequence determinants of IDP conformational properties. They may also serve as an asset for rational design of non-natural IDPs with tunable degree of compactness.
BACKGROUND: Recent theoretical and computational studies have shown that the charge content and, most importantly, the linear distribution of opposite charges are major determinants of conformational properties of intrinsically disordered proteins (IDPs). Charge segregation in a sequence can be measured through κ, which represents a normalized measure of charge asymmetry. A strong inverse correlation between κ and radius of gyration has been previously demonstrated for two independent sets of permutated IDP sequences. METHODS: We used two well-characterized IDPs, namely measles virus NTAIL and Hendra virus PNT4, sharing a very similar fraction of charged residues and net charge per residue, but differing in proline (Pro) content. For each protein, we have rationally designed a low- and a high-κ variant endowed with the highest and the lowest κ values compatible with their natural amino acid composition. Then, the conformational properties of wild-type and κ-variants have been assessed by biochemical and biophysical techniques. RESULTS: We confirmed a direct correlation between κ and protein compaction. The analysis of our original data along with those available from the literature suggests that Pro content may affects the responsiveness to charge clustering. CONCLUSIONS: Charge clustering promotes IDP compaction, but the extent of its effects depends on the sequence context. Proline residues seem to play a role contrasting compaction. GENERAL SIGNIFICANCE: These results contribute to the identification of sequence determinants of IDP conformational properties. They may also serve as an asset for rational design of non-natural IDPs with tunable degree of compactness.
Authors: Greta Bianchi; Marco Mangiagalli; Alberto Barbiroli; Sonia Longhi; Rita Grandori; Carlo Santambrogio; Stefania Brocca Journal: Biomolecules Date: 2022-04-09
Authors: Lena Maria Murschall; Anne Gerhards; Thomas MacVicar; Esra Peker; Lidwina Hasberg; Stephan Wawra; Thomas Langer; Jan Riemer Journal: BMC Biol Date: 2020-08-06 Impact factor: 7.431