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Nanoparticles (NPs) functionalized with antibodies (Abs) on their surface are used in a wide range of bioapplications. Whereas the attachment of antibodies to single NPs to trigger the internalization in cells via receptor-mediated endocytosis has been widely studied, the conjugation of antibodies to larger NP assemblies has been much less explored. Taking into account that NP assemblies may be advantageous for some specific applications, the possibility of incorporating targeting ligands is quite important. Herein, we performed the effective conjugation of antibodies onto a fluorescent NP assembly, which consisted of fluorinated Quantum Dots (QD) self-assembled through fluorine-fluorine hydrophobic interactions. Cellular uptake studies by confocal microscopy and flow cytometry revealed that the NP assembly underwent the same uptake procedure as individual NPs; that is, the antibodies retained their targeting ability once attached to the nanoassembly, and the NP assembly preserved its intrinsic properties (i.e., fluorescence in the case of QD nanoassembly)., This research was financially supported by the research core of TMU (Grant No: IG-39707) and the Biotechnology Development Council of the Islamic Republic of Iran (Grant No: 950709). Part of this work was funded by the Cluster of Excellence ‘Advanced Imaging of Matter’ of the Deutsche Forschungsgemeinschaft (DFG)-EXC 2056-project ID 390715994.

Guaianolides are an important class of sesquiterpene lactones with unique biological and pharmaceutical properties. They have been postulated to be derived from germacranolides, but for years no progress has been made in the elucidation of their biosynthesis that requires an unknown cyclization mechanism. Here we demonstrate the isolation and characterization of a cytochrome P450 from feverfew (Tanacetum parthenium), kauniolide synthase. Kauniolide synthase catalyses the formation of the guaianolide kauniolide from the germacranolide substrate costunolide. Unlike most cytochrome P450s, kauniolide synthase combines stereoselective hydroxylation of costunolide at the C3 position, with water elimination, cyclization and regioselective deprotonation. This unique mechanism of action is supported by in silico modelling and docking experiments. The full kauniolide biosynthesis pathway is reconstructed in the heterologous hosts Nicotiana benthamiana and yeast, paving the way for biotechnological production of guaianolide-type sesquiterpene lactones., Q.L. was funded as a part of Terpmed (Plant Terpenoids for Human Health: a chemical and genomic approach to identify and produce bioactive compounds) (Project ID 227448) and A.B.K. was funded by Iranian Ministry of Science Research and Technology.

Calcineurin is an essential calcium‐activated serine/threonine phosphatase. The six NMR‐observable methionine methyl groups in the catalytic domain of human calcineurin Aα (CNA) were assigned and used as reporters of the presence of potential cis‐trans isomers in solution. Proline 84 is found in the cis conformation in most calcineurin X‐ray structures, and proline 309, which is part of a highly conserved motif in phosphoprotein phosphatases, was modeled with a cis peptide bond in one of the two molecules present in the asymmetric unit of CNA. We mutated each of the two prolines to alanine to force the trans conformation. Solution NMR shows that the P84A CNA mutant exists in two forms, compatible with cis‐trans isomers, while the P309A mutant is predominantly in the trans conformation., The work was partially supported by funds from the Spanish Ministry of Economy, Industry, and Competitiveness (MINECO) (BIO2016‐78006R, to MP; BFU2015‐71092‐P to IF; SAF2015‐66365 and RTC‐2015‐3386‐1, to MP‐R; Units of Excellence María de Maeztu awards to IF (MDM‐2014‐0435) and to JCP (MDM‐2017–076). Some of the funds were cofinanced with the European Fund for Regional Development (FEDER). We acknowledge additional support from Generalitat de Catalunya (2014‐SGR‐541 and 2017‐SGR‐191). A.B. was funded by the RTC‐2015‐3381‐1 grant. S.C. was a recipient of a short‐term fellowship from the Iranian Government.

Strategic move: Isatin as a core structure has inspired the development of useful catalytic strategies to give access to interesting molecular architectures with biological activity., We thank the Ministry of Science and Innovation (CTQ2010-19606-C02-01) and Aragon Government (E-10) for financial support of our research. R.H. and S.M. thank the Iranian Government for their fellowships and financial support.