Part:BBa_K4674000

mGreenLantern (mGL)

The mGL fluorescent protein is developed for the expression in the mammalian systems, since the low soluibity or misfolding of eGFP limit the total fluorescence output of whole cells.

Cellular Brightness and Maturation

In the characterization, nGL shows 630% greater brightness than eGFP. The maturation half-time of mGL is 13.5 min, which is 207% faster than eGFP (33.0min). mGL is compatible with common EGFP filter sets and the popular 488-nm argon-ion laser line for widefield and confocal microscopy. Its excitation and emission peaks of 503/514 nm additionally make it well matched to newer solid-state 491-nm lasers and 505-nm light-emitting diodes (LEDs).

Biochemical Characterization

The QY and EC of mGreenLantern (ϕ = 0.72, ε = 101 mM−1⋅cm−1) compare favorably with those of other bright GFPs such as Clover (ϕ = 0.75, ε = 97 mM−1⋅cm−1), and its low pKa of 5.6 indicates greater acid resistance than EGFP.

mGreenLantern completely lacks a 405-nm absorbance peak, unlike EGFP and Clover, suggesting that it will be better suited for multicolor imaging with T-Sapphire.

Chemical and thermal stability In the strongly denaturing solution of 6.3 M guanidinium HCl, pH 7.5, mGL persisted for 100 s before reaching half the fluorescence of its native control wells, while other fluorescent protein (e.g. eGFP, eYFG, and Clover) denatured instantly. The melting temperture of mGL is 87.2 °C, which is much higher than the mNeonGreen (68.0 °C), eGFP (80.3 °C), or sfGFP (86.4 °C)

Antibody recognition The mGL protien could be recognized at least by three commercial antibodies (goat α-GFP polyclonal, Abcam, #ab6673; or goat α-GFP polyclonal, Novus, #NB1001770; or Ms α-GFP monoclonal, Life Technologies, #A-11122). The truth that 91% sequence identity of mGL shared with eGFP strongly implies that mGL is readily compatible with existing technology for EGFP affinity-related applications.

Photostability When analyzed using normalized bleaching plots beginning at time 0 to include the Emerald-like behavior, mGreenLantern’s photostability was better than Venus and lower than Clover.

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Table 1. Spectroscopic characterization of fluorescent protein (quoted from (Campbell et. al. 2020)

Reference Benjamin C. Campbell, Elisa M. Nabel, Mitchell H. Murdock, and Gregory A. Petsko. mGreenLantern: a bright monomeric fluorescent protein with rapid expression and cell filling properties for neuronal imaging. Proc Natl Acad Sci U S A. 2020 Dec 1;117(48):30710-30721

Sequence and Features

Assembly Compatibility:

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• 1000
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