scholarly journals Cover Feature: Bioinspired Design of Lysolytic Triterpenoid–Peptide Conjugates that Kill African Trypanosomes (ChemBioChem 10/2019)

ChemBioChem ◽  
2019 ◽  
Vol 20 (10) ◽  
pp. 1208-1208
Author(s):  
W.‐Matthias Leeder ◽  
Fabian Giehler ◽  
Juliane Joswig ◽  
H. Ulrich Göringer
ChemBioChem ◽  
2019 ◽  
Vol 20 (10) ◽  
pp. 1251-1255
Author(s):  
W.‐Matthias Leeder ◽  
Fabian Giehler ◽  
Juliane Joswig ◽  
H. Ulrich Göringer

2018 ◽  
Author(s):  
W.-Matthias Leeder ◽  
Fabian Giehler ◽  
Juliane Joswig ◽  
H. Ulrich Göringer

AbstractHumans have evolved a natural immunity against Trypanosoma brucei infections, which is executed by two serum (lipo)protein complexes known as trypanolytic factors (TLF). Active TLF-ingredient is the primate-specific apolipoprotein L1 (ApoL1). The protein has a pore-forming activity that kills parasites by lysosomal and mitochondrial membrane fenestration. Of the many trypanosome subspecies only two are able to counteract the activity of ApoL1, which illustrates its evolutionary optimized design and trypanocidal potency. Here we ask the question whether a synthetic (syn)TLF can be synthesized using the design principles of the natural TLF-complexes but relying on different chemical building blocks. We demonstrate the stepwise development of triterpenoid-peptide conjugates, in which the triterpenoids act as a cell binding, uptake and lysosomal transport-moduls and the synthetic peptide GALA as a pH-sensitive, pore-forming lysolytic toxin. As designed, the conjugate kills infective-stage African trypanosomes through lysosomal lysis demonstrating proof-of-principle for the bioinspired, forward-design of a synTLF.


2019 ◽  
Vol 18 (9) ◽  
pp. 1289-1294 ◽  
Author(s):  
Kusum Vats ◽  
Rohit Sharma ◽  
Haladhar D. Sarma ◽  
Drishty Satpati ◽  
Ashutosh Dash

Aims: The urokinase Plasminogen Activator Receptors (uPAR) over-expressed on tumor cells and their invasive microenvironment are clinically significant molecular targets for cancer research. uPARexpressing cancerous lesions can be suitably identified and their progression can be monitored with radiolabeled uPAR targeted imaging probes. Hence this study aimed at preparing and evaluating two 68Ga-labeled AE105 peptide conjugates, 68Ga-NODAGA-AE105 and 68Ga-HBED-CC-AE105 as uPAR PET-probes. Method: The peptide conjugates, HBED-CC-AE105-NH2 and NODAGA-AE105-NH2 were manually synthesized by standard Fmoc solid phase strategy and subsequently radiolabeled with 68Ga eluted from a commercial 68Ge/68Ga generator. In vitro cell studies for the two radiotracers were performed with uPAR positive U87MG cells. Biodistribution studies were carried out in mouse xenografts with the subcutaneously induced U87MG tumor. Results: The two radiotracers, 68Ga-NODAGA-AE105 and 68Ga-HBED-CC-AE105 that were prepared in >95% radiochemical yield and >96% radiochemical purity, exhibited excellent in vitro stability. In vivo evaluation studies revealed higher uptake of 68Ga-HBED-CC-AE105 in U87MG tumor as compared to 68Ga-NODAGAAE105; however, increased lipophilicity of 68Ga-HBED-CC-AE105 resulted in slower clearance from blood and other non-target organs. The uPAR specificity of the two radiotracers was ascertained by significant (p<0.05) reduction in the tumor uptake with a co-injected blocking dose of unlabeled AE-105 peptide. Conclusion: Amongst the two radiotracers studied, the neutral 68Ga-NODAGA-AE105 with more hydrophilic chelator exhibited faster clearance from non-target organs. The conjugation of HBED-CC chelator (less hydrophilic) resulted in negatively charged 68Ga-HBED-CC-AE105 which was observed to have high retention in blood that decreased target to non-target ratios.


Peptides ◽  
2019 ◽  
Vol 117 ◽  
pp. 170079 ◽  
Author(s):  
Natalia Ptaszyńska ◽  
Katarzyna Olkiewicz ◽  
Joanna Okońska ◽  
Katarzyna Gucwa ◽  
Anna Łęgowska ◽  
...  

2019 ◽  
Vol 98 ◽  
pp. 181-188 ◽  
Author(s):  
Irina Matetovici ◽  
Linda De Vooght ◽  
Jan Van Den Abbeele

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