Supporting Information InhibitorGCPII interaction: selective and robust system for targeting cancer cells with structurally diverse nanoparticles Jitka Neburkova 1,2 # , Frantisek Sedlak 1,2,3 # , Jirina Zackova Suchanova 3 # , Libor Kostka 4 , Pavel Sacha 1 , Vladimir Subr 4 , Tomas Etrych 4 , Petr Simon 1 , Jitka Barinkova 1 , Robin Krystufek 1 , Hana Spanielova 1,3 , Jitka Forstova 3 , Jan Konvalinka 1,5 , Petr Cigler 1 * 1 Institute of Organic Chemistry and Biochemistry of the CAS, Flemingovo namesti 2, 166 10 Prague, Czech Republic 2 First Faculty of Medicine, Charles University, Katerinska 32, 121 08 Prague, Czech Republic 3 Department of Genetics and Microbiology, Faculty of Science, Charles University, Vinicna 5, 128 44 Prague 2, Czech Republic 4 Institute of Macromolecular Chemistry of the CAS, Heyrovskeho namesti 2, 162 06, Prague 6, Czech Republic 5 Department of Biochemistry, Faculty of Science, Charles University, Hlavova 2030, 128 43 Prague 2, Czech Republic * cigler@uochb.cas.cz, Fax: (+)420–220–183–578, Telephone: (+)420–220–183–429 # These authors contributed equally. Synthesis of GCPII inhibitors All chemicals were purchased from SigmaAldrich unless otherwise stated. All final compounds were purified using a preparative scale Jasco PU986 HPLC (flow rate 10 ml/min), equipped with a YMC C18 Prep Column, 5 µm, 250 x 20 mm. Purity was tested on an analytical Jasco PU1580 HPLC (flow rate 1 ml/min), invariable gradient 2100% in 30 min unless otherwise stated, equipped with a Watrex C18 Analytical Column, 5 µm, 250 x 5 mm. Final compounds were of at least 99% purity. Structures were confirmed by HRMS at LTQ Orbitrap XL (Thermo Fisher Scientific). Compound 1 (1amino40(4bromobenzyl)39,47dioxo3,6,9,12,15,18,21,24,27,30,33,36dodecaoxa 40,46,48triazahenpentacontane45,49,51tricarboxylic acid TFA salt) was synthesized according to the procedure described by Sacha et al, 1 but replacing BocNHPEG 5 COOH with BocNHPEG 12  COOH (PurePEG, LLC). The overall yield was 10%. HRMS (ESIpos.) C 46 H 80 BrN 4 O 20 [M+H] + calc. 1087.4549; found 1087.4525. Compound 2 was prepared as previously described. 2 Compounds 4 and 5 (GCPII inhibitors with alkyne or azide) were synthesized as shown in Scheme S1.