I am working on a project where I am designing an aerosol formulation of my therapeutical peptide. I would like to do the study of biodistribution in vivo (mice), so I used cy5-labelled peptide and detect cy5 fluorescence in organs. Because I am now using a freeze-drying method, which means I am making aerosol from water solution to dry powder, the water solubility is very improtant. I could not dissolve cy5-labelled peptide in water so I add some DMSO in my formulation. However, the status of dry powder was very bad and it was difficult to administrate the aerosol as the powder was not fine enough. I believe it was because of the participation of DMSO in the formulation.
Thus, I am now looking for a suitable flourescence label for my peptide that will not highly decrease the water solubility. Is there any suggestions? Thank you!
Note: the peptide and backbone material are well hydrophilic.
Dear Yongren Li ,
You might have a look at https://en.wikipedia.org/wiki/Cyanine under 'alternatives' you can read and I quote “Many analogs of standard Cy 2 / 3 / 3.5 / 5 / 5.5 / 7 / 7.5 dyes were developed, using diverse modification: Alexa Fluor dyes, Dylight, FluoProbes dyes, Sulfo Cy dyes,[12] Seta dyes,[13] IRIS dyes from Cyanine Technologies [14] and others can be used interchangeably with Cy dyes in most biochemical applications, with claimed improvements in solubility, fluorescence, or photostability.[15][16]”
Potentially interesting might be the Alexa Fluor family of fluorescent dyes originally from Molecular Probes, nowadays Thermo Fisher Scientific. Alexa Fluor dyes are negatively charged and thus more hydrophilic and soluble see for example:
He Tian, Thomas P. Sakmar, Thomas Huber, Chapter 15 - Site-Specific Labeling of Genetically Encoded Azido Groups for Multicolor, Single-Molecule Fluorescence Imaging of GPCRs, Editor(s): P. Michael Conn, Methods in Cell Biology, Academic Press, Volume 117, 2013, Pages 267-303, ISSN 0091-679X, ISBN 9780124081437, https://doi.org/10.1016/B978-0-12-408143-7.00015-3(see enclosed file)
See for example SCHEME 15.3 for some structures
Best regards.
- Badges
- Science topic
- Similar topics
- Biological Science
- Molecular Biology
- Molecular Methods
- Cloning