Comparison List


GZnP3 is a basic (constitutively fluorescent) green fluorescent protein published in 2019, derived from Aequorea victoria.
Oligomerization Organism Molecular Weight Cofactor
Monomer Aequorea victoria - -

FPbase ID: 1E8G7


State Ex λ Em λ EC (M-1 cm-1) QY Brightness pKa Maturation (min) Lifetime (ns)
GZnP3 (apo state) 488 512 4,000 0.112 0.45      
GZnP3 (Zn²⁺-bound) 488 512 23,400 0.462 10.81      
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GZnP3 Sequence

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"The development of GZnP3 has filled such a gap for the scientific community giving an unprecedented ability to study cellular Zn²⁺ dynamics with sub-nanomolar sensitivity in real time. GZnP3 binds labile Zn²⁺ with a Kd of 1.3 nM, giving it the ability to detect this metal ion in the sub-nanomolar range. Though other genetically encoded Zn²⁺ probes have similar binding affinities (Table 1), GZnP3 has approximately an 11-fold dynamic range from its apo state to Zn²⁺ saturation (17-fold in vitro), making it the most sensitive protein-based Zn²⁺ sensor currently available for monitoring sub-nanomolar cellular Zn²⁺ dynamics, between 100 pM and 1 nM. It has high specificity for Zn²⁺ over a range of other biologically relevant cations, including Ca²⁺ and Fe²⁺. Together, these characteristics permit the use of GZnP3 to observe minute changes in cytosolic [Zn²⁺] from the high picomolar to low nanomolar range. Though it is a powerful tool, it does have limitations for its use in the dynamic cellular environment. Primarily, like many GFP-based fluorophores, we are aware of its sensitivity to changes in pH. To account for this, however, we have established a normalization method to obtain pH-corrected GZnP3 signals by simultaneously recording GZnP3 (Zn²⁺) and pHuji (pH) signals (Supplementary Fig. 5)."

Minckley et al. (2019)

Primary Reference

Sub-nanomolar sensitive GZnP3 reveals TRPML1-mediated neuronal Zn2+ signals

Minckley Tf, Zhang C, Fudge Dh, Dischler Am, Lejeune Kd, Xu H, Qin Y

(2019). Nature Communications, 10(1) , 4806. doi: 10.1038/s41467-019-12761-x. Article   Pubmed

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