The present invention provides novel fluorescein derivative compounds having fluorescence spectrum and quantum yield characteristics similar to those of fluorescein. The compounds are readily synthesized and purified and are readily soluble in water at self-quenching concentrations. Significantly, due to the presence of polar polyhydroxy group substituents and the absence of metal-chelating groups, these fluorescein derivatives are susceptible to minimal leakage across liposome membranes and have fluorescence characteristics minimally sensitive to the presence of metal ions. Compounds of the invention are thus exceptionally suitable for use in the development of highly storage stable liposome preparations to be employed in immunolytic assays involving human body fluid samples.
Rapid, Stable, Chemoselective Labeling of Thiols with Julia-Kocieński-like Reagents: A Serum-Stable Alternative to Maleimide-Based Protein Conjugation
作者:Narihiro Toda、Shigehiro Asano、Carlos F. Barbas
DOI:10.1002/anie.201306241
日期:2013.11.25
Exquisite chemoselectivity for cysteine has been found for methylsulfonylphenyloxadiazole compounds under various buffer conditions. Furthermore, the resulting protein conjugates have superior stability to cysteine–maleimide conjugates in human plasma (HSA=human serum albumin, MBP‐C‐HA=maltose‐binding protein). This new thiol‐click reaction offers a new approach to generate stable protein conjugates