Comparison List


a.k.a. QC2-6 FIQ

similar: StayGold

mStayGold is a basic (constitutively fluorescent) green fluorescent protein published in 2023, derived from Cytaeis uchidae. It has low acid sensitivity.
Oligomerization Organism Molecular Weight Cofactor
Monomer Cytaeis uchidae 25.6 kDa -

FPbase ID: 5H7QY


Ex λ Em λ EC (M-1 cm-1) QY Brightness pKa Maturation (min) Lifetime (ns)
499 510 164,000 0.83 136.12 4.8   2.79


No photostability measurements available ... add one!

mStayGold Sequence

mStayGold was derived from QC2-6 with the following mutations: R144I/T155Q/Y187F
amino acid numbers relative to CU17S. show relative to QC2-6

GenBank: LC756333


We noticed, that QC2-6 yielded a substantial number of puncta in a Fluoppi assay (score, 55.6%). With this unacceptable result, we decided to drive the monomerization further on the basis of QC2-6. Performing combinatorial saturation mutagenesis at Tyr187, Arg144 and Thr155 and screening for brightness, photostability and monomericity yielded QC2-6 FIQ, which contained Y187F, R144I and T155Q mutations relative to QC2-6. QC2-6 FIQ gave high scores for both OSER (92.3%) and Fluoppi (100%) assays.

Ando et al. (2023)

Primary Reference

Additional References

External Resources

Change history

Something missing or incorrect? Submit a change Submit a change