Figure 8. Model for determining Co 2... | Rockefeller University Press

Figure 8.

$Figure 8. Model for determining Co2+ density on the plasma membrane of unroofed cells from its quenching of R18. (A) Cartoon depicting the concept of Rc, the distance of closest approach between the donor (head group of R18) and acceptor (Co2+ bound to head group of C18-NTA). (B) Relationship between mole fraction Co2+-bound C18-NTA and FRET efficiency as measured from quenching of R18. For convenience, an axis is also shown for acceptor density. Predictions from the Fung and Stryer (1978) model are shown for an Rc of 5 Å (red) and 10 Å (blue). The red region shows how the 25–75th percentile of the FRET efficiencies, calculated from the data in Fig. 7 using Eq. 2, translates into mole fraction of Co2+-C18-NTA.$

Model for determining Co²⁺ density on the plasma membrane of unroofed cells from its quenching of R18. (A) Cartoon depicting the concept of R_c, the distance of closest approach between the donor (head group of R18) and acceptor (Co²⁺ bound to head group of C18-NTA). (B) Relationship between mole fraction Co²⁺-bound C18-NTA and FRET efficiency as measured from quenching of R18. For convenience, an axis is also shown for acceptor density. Predictions from the Fung and Stryer (1978) model are shown for an R_c of 5 Å (red) and 10 Å (blue). The red region shows how the 25–75th percentile of the FRET efficiencies, calculated from the data in Fig. 7 using Eq. 2, translates into mole fraction of Co²⁺-C18-NTA.