Table 1.
Molecular characteristics of the interleukins.
| Name | Number of Amino Acids | Molecular Mass [kDa] | Isoelectric Point | Percentage of Hydrophilic Amino Acids | Percentage of Hydrophobic Amino Acids | Secondary Structure | Receptors | Reference | |
|---|---|---|---|---|---|---|---|---|---|
| α-Helix | Β-Strand | ||||||||
| IL-1 | 219 | 24.243 | 6.55 | 59.82 | 40.18 | 1 | 12 | IL-1R1, IL-1R2 | [46] |
| IL-2 | 153 | 17.628 | 7.08 | 56.21 | 43.79 | 5 | 3 | IL-2RA, IL-2RB, IL-2RG | [47] |
| IL-3 | 152 | 17.233 | 7.96 | 50.66 | 49.34 | 5 | 1 | IL-3RA, IL-3RB | [48] |
| IL-4 | 153 | 17.492 | 8.15 | 62.74 | 37.26 | 7 | 2 | IL-4R | [49] |
| IL-5 | 134 | 15.238 | 7.44 | 56.72 | 43.28 | 4 | 0 | IL-5RA, IL-3RB | [50] |
| IL-6 | 212 | 23.718 | 5.98 | 56.60 | 43.40 | 6 | 0 | IL-6R | [51] |
| IL-7 | 177 | 20.187 | 7.83 | 59.32 | 40.68 | 4 | 0 | IL-7R | [52] |
| IL-8 | 99 | 11.098 | 8.11 | 53.53 | 46.47 | 2 | 4 | IL8RB | [53] |
| IL-9 | 144 | 15.909 | 7.72 | 59.03 | 40.97 | 5 | 0 | IL-9R | [54] |
| IL-10 | 178 | 20.517 | 7.23 | 59.55 | 40.45 | 4 | 0 | IL-10RA | [55] |
| IL-11 | 199 | 21.429 | 10.5 | 44.72 | 55.28 | 7 | 0 | IL-11RA | [56] |
| IL-12 subunit alpha | 219 | 24.874 | 5.93 | 55.25 | 44.75 | 5 | 0 | IL-12RB1 | [57] |
| IL-12 subunit beta | 328 | 37.169 | 5.36 | 63.11 | 36.89 | 2 | 24 | [58] | |
| IL-13 | 146 | 15.816 | 7.64 | 49.31 | 50.69 | 4 | 1 | IL-13RA1, IL-13RA2 | [59] |
| IL-14 | 546 | 61.891 | 5.93 | 69.05 | 30.95 | 2 | 0 | Unkown | [60] |
| IL-15 | 162 | 18.086 | 5.00 | 58.02 | 41.96 | 5 | 0 | IL-15RA | [61] |
| Pro-IL-16 | 1332 | 141.752 | 7.19 | 61.94 | 38.06 | 10 | 24 | CD4 | [62] |
| IL-17A | 155 | 17.504 | 7.76 | 59.35 | 40.65 | 1 | 6 | IL-17RA | [63] |
| IL-18 | 193 | 22.326 | 4.41 | 61.66 | 38.34 | 2 | 16 | IL-18R1 | [64] |
| IL-19 | 177 | 20.452 | 6.88 | 57.63 | 42.37 | 7 | 0 | IL-20R | [65] |
| IL-20 | 176 | 20.072 | 7.91 | 59.09 | 40.91 | 6 | 1 | IL-20R | [66] |
| IL-21 | 162 | 18.653 | 8.67 | 63.58 | 36.42 | 6 | 0 | IL-21R | [67] |
| IL-22 | 179 | 20.011 | 7.00 | 55.31 | 44.69 | 7 | 0 | IL2-2RA1 | [68] |
| IL-23 alfa | 189 | 20.730 | 5.73 | 53.97 | 46.03 | 7 | 0 | IL-23R | [69] |
| IL-24 | 206 | 23.825 | 8.05 | 51.94 | 48.06 | 6 | 1 | IL-20R | [70] |
| IL-25 | 177 | 20.330 | 7.55 | 62.15 | 37.85 | 0 | 6 | LY6E | [71] |
| IL-26 | 171 | 19.843 | 9.22 | 57.89 | 42.11 | 5 | 0 | IL-20R1 | [72] |
| IL-27 subunit alpha | 243 | 27.493 | 5.94 | 51.44 | 48.56 | 7 | 0 | IL-27RA | [73] |
| IL-27 subunit beta | 229 | 25.396 | 8.83 | 49.78 | 50.22 | 1 | 15 | IL-27RA | [74] |
| IL-28 Interferon lambda receptor 1 | 520 | 57.653 | 4.8 | 57.11 | 42.89 | 3 | 19 | IL-28R | [75] |
| IL-29 Interferon lambda-1 | 200 | 21.898 | 8.09 | 52.50 | 47.50 | 8 | 0 | Unknown | [76] |
| IL-30 | 243 | 27.493 | 5.94 | 51.44 | 48.56 | 7 | 0 | Unknown | [77] |
| IL-31 | 164 | 18.205 | 5.12 | 57.32 | 42.68 | 4 | 0 | IL-31RA | [77,78] |
| IL-32 | 234 | 26.676 | 5.03 | 58.97 | 41.03 | 8 | 2 | Unknown | [77,79] |
| IL-33 | 270 | 30.759 | 7.86 | 64.81 | 35.19 | 4 | 15 | Unknown | [77,80] |
| IL-34 | 242 | 27.482 | 6.47 | 54.96 | 45.04 | 7 | 1 | Unknown | [77,81] |
| IL-35 | it consists of two subunits: IL-12α and IL-27β | Unknown | [77] | ||||||
| IL-36 alpha | 158 | 17.684 | 5.65 | 56.96 | 43.04 | 2 | 12 | Unknown | [77,82] |
| IL-36 beta | 164 | 18.522 | 8.72 | 62.19 | 37.81 | 0 | 10 | Unknown | [77,83] |
| IL-36 gamma | 168 | 18.721 | 4.94 | 59.76 | 40.24 | 2 | 13 | Unknown | [77,84] |
| IL-37 | 218 | 24.126 | 5.82 | 59.17 | 40.83 | 1 | 12 | IL-18Ra, IL-18BP | [77,85] |
| IL-38 Interleukin-1 family member 10 | 152 | 16.943 | 4.88 | 57.89 | 42.11 | 2 | 12 | IL-1R1, IL-36R | [77,86] |
| IL-39 | composed of the IL-23p19 alpha subunit and Ebi3 beta subunit. | IL-23R, IL-27R, and gp130 | [45,77] | ||||||
| IL-40 | 265 | 29.091 | 7.83 | 54.72 | 45.28 | 1 | 18 | [77,87] | |