Table 2.
Site-specific 13C transverse relaxation rates of acyl chains of POPC:POPG (4:1) membrane and Mn2+ and Fp dependences (uncertainties in parentheses)a
| 13C | R2 (s−1) | Γ2 (s−1) | ||||
|---|---|---|---|---|---|---|
| w/o Fp | 3% Fp | w/o Fp | 3% Fp | |||
| w/o Mn2+ | 0.5% Mn2+ | w/o Mn2+ | 0.5% Mn2+ | |||
| 2,2′ | 28.8(1.4) | 51.5(2.1) | 28.1(1.2) | 63.5(3.2) | 22.8(2.6) | 35.4(3.4) |
| 3,3′ | 20.0(1.5) | 35.2(2.4) | 21.3(2.0) | 51.1(4.0) | 15.2(2.8) | 29.8(4.1) |
| 8,11 | 9.1(0.7) | 12.6(0.9) | 13.6(1.6) | 19.8(1.7) | 3.5(1.2) | 6.2(2.3) |
| 9,10 | 8.4(0.6) | 11.9(0.8) | 8.7(1.0) | 13.0(1.2) | 3.5(1.0) | 4.3(1.2) |
| 16,14′ | 15.5(0.7) | 15.0(0.6) | 13.8(0.8) | 15.4(0.7) | −0.5(0.9) | 1.5(1.0) |
| 17,15′ | 5.9(0.7) | 7.3(0.4) | 8.6(0.8) | 9.7(1.0) | 1.4(0.8) | 1.1(1.2) |
| *{4–7,12–15,4′−13′} | 15.8(0.3) | 20.5(0.9) | 17.8(0.7) | 24.1(1.1) | 4.7(0.9) | 6.4(1.3) |
| *1{ 6′−9′} | 24.8(0.2) | 27.2(1.5) | 25.4(0.5) | 30.3(0.3) | 2.5(1.6) | 4.9(0.6) |
| *2{ 7,10′,11′} | 15.1(0.2) | 16.4(0.9) | 16.0(0.7) | 23.2(1.0) | 1.3(0.9) | 7.2(1.2) |
| *3{4–6,12–15,4′,5′,12′,13′} | 11.7(0.3) | 18.8(0.9) | 15.8(1.2) | 23.1(1.8) | 7.1(1.0) | 7.4(2.2) |
Each 13C transverse relaxation rate (R2) was determined from best-fitting the integrated NMR peak intensity S vs. delay time τ using S(τ) = A × exp(−R2 × τ) where A and R2 are fitting parameters. The fitting uncertainty of R2 is given in parentheses. The Γ2 values are the differences between the best-fit R2 values of samples with vs. without Mn2+. Typical ppm integration ranges for peaks are: 2,2’, 33.00–37.00; 3,3’, 24.00–26.30; 8,11, 26.50–28.20; 9,10, 128.00–131.00; 16,14’, 31.50–33.00; 17,15’, 21.50–23.60; *, 28.30–31.50; *1, 30.24–31.50; *2, 30.04–30.24; *3, 28.30–30.04 (Fig. S2). The 13C sites that make the largest contributions to the *1, *2, and *3 integration ranges are listed between the brackets. The % Mn2+ = (mole bound Mn2+)/(mole lipid) × 100. The % Fp is calculated using the same type of expression.