RT Journal Article
SR Electronic
T1 Identification of a New Prostate-Specific Cyclic Peptide with the Bacterial FliTrx System
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 782
OP 785
VO 46
IS 5
A1 Sabine Zitzmann
A1 Susanne Krämer
A1 Walter Mier
A1 Miriam Mahmut
A1 Julian Fleig
A1 Annette Altmann
A1 Michael Eisenhut
A1 Uwe Haberkorn
YR 2005
UL http://jnm.snmjournals.org/content/46/5/782.abstract
AB Peptides are useful tools for directing radioisotopes into tumors. We evaluated the ability of a bacterial peptide display system to isolate new prostate tumor-specific peptides. Methods: We used the bacterial FliTrx system to identify a new cyclic peptide that binds to prostate carcinoma. Serum stability and binding affinities of the 125I-labeled peptide were tested. Furthermore, the 131I-labeled peptide was used to evaluate its biodistribution. Results: Several peptides showing a potential consensus motif were identified. The new peptide MM-2 is stable in serum for up to 24 h. It binds to PC-3 cells, and this binding can be inhibited more than 70% with the unlabeled peptide. Binding to human umbilical vein endothelial cells (HUVECs) and PNT-2 cells is weaker, and competition (27%) in HUVECs is less efficient. The biodistribution showed moderate accumulation in tumor. Conclusion: Bacterial peptide display, an alternative to phage peptide display, can allow the identification of specific binding and stable peptides.