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Several protein‐drug conjugates are currently being used in cancer therapy. These conjugates rely on cytotoxic organic compounds that are covalently attached to the carrier proteins or that interact with them via non‐covalent interactions. Human transthyretin (TTR), a physiological protein, has already been identified as a possible carrier protein for the delivery of cytotoxic drugs. Here we show the structure‐guided development of a new stable cytotoxic molecule based on a known strong binder of TTR and a well‐established anticancer drug. This example is used to demonstrate the importance of the integration of multiple biophysical and structural techniques, encompassing microscale thermophoresis, X‐ray crystallography and NMR. In particular, we show that solid‐state NMR has the ability to reveal effects caused by ligand binding which are more easily relatable to structural and dynamical alterations that impact the stability of macromolecular complexes. [ABSTRACT FROM AUTHOR]

Metalloproteins constitute a significant fraction of the proteome of all organisms and their characterization is critical for both basic sciences and biomedical applications. A large portion of metalloproteins bind paramagnetic metal ions, and paramagnetic NMR spectroscopy has been widely used in their structural characterization. However, the signals of nuclei in the immediate vicinity of the metal center are often broadened beyond detection. In this work, we show that it is possible to determine the coordination environment of the paramagnetic metal in the protein at a resolution inaccessible to other techniques. Taking the structure of a diamagnetic analogue as a starting point, a geometry optimization is carried out by fitting the pseudocontact shifts obtained from first principles quantum chemical calculations to the experimental ones. [ABSTRACT FROM AUTHOR]

Abstract: Starting from 3-aza-6,8-dioxa-bicyclo[3.2.1]octane scaffold (BTAa) a virtual library of molecules was generated and screened in silico against the crystal structure of the Human Macrophage Metalloelastase (MMP-12). The molecules obtaining high score were synthesized and the affinity for the catalytic domain of MMP-12 was experimentally proved by NMR experiments. A BTAa scaffold 20 having a N-hydroxyurea group in position 3 and a p-phenylbenzylcarboxy amide in position 7 showed a fair inhibition potency (IC50 =149μM) for MMP-12 and some selectivity towards five different MMPs. These results, taken together with the X-ray structure of the adduct between MMP-12, the inhibitor 20 and the acetohydroxamic acid (AHA), suggest that bicyclic scaffold derivatives may be exploited for the design of new selective matrix metalloproteinase inhibitors (MMPIs). [Copyright &y& Elsevier]