The Emperor's new clothes: Myths and truths of in-cell NMR

• Published in: Archives of biochemistry and biophysics Vol. 628; pp. 114 - 122
• Main Authors: Pastore, Annalisa, Temussi, Piero Andrea
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.08.2017
• Subjects: Animals; Cellular environment; Confinement; Humans; Molecular crowding; NMR; Nuclear Magnetic Resonance, Biomolecular - methods; Protein Unfolding; Proteins - chemistry; Spin Labels; Cellular environment; Confinement; NMR; Molecular crowding
• ISSN: 0003-9861; 1096-0384
• DOI: 10.1016/j.abb.2017.02.008

In-cell NMR is a technique developed to study the structure and dynamical behavior of biological macromolecules in their natural environment, circumventing all isolation and purification steps. In principle, the potentialities of the technique are enormous, not only for the possibility of bypassing all purification steps but, even more importantly, for the wealth of information that can be gained from directly monitoring interactions among biological macromolecules in a natural cell. Here, we review critically the promises, successes and limits of this technique as it stands now. Interestingly, many of the problems of NMR in bacterial cells stem from the artificially high concentration of the protein under study whose overexpression is anyway necessary to select it from the background. This has, as a consequence, that when overexpressed, most globular proteins, do not show an NMR spectrum, limiting the applicability of the technique to intrinsically unfolded or specifically behaving proteins. The outlook for in-cell NMR of eukaryotic cells is more promising and is possibly the most attracting aspect for the future. •In-cell NMR is very useful to study bio-macromolecules in their natural environment.•Interactions among biological macromolecules in a natural cell can be gained directly.•Artificially high concentration in prokaryotic cells hinders spectral observation.•Best results are obtained with intrinsically unfolded proteins.•The outlook for in-cell NMR of eukaryotic cells is more promising.