Class II MHC molecule | β37 | β57 |
|---|
DRB1*0701 | F | V |
DRB1*0706 | F | A |
DRB1*0708 | V | V |
DRB1*0709 | F | V |
DRB1*0809 | F | D |
DRB1*0821 | F | D |
DRB1*1110 | F | D |
DRB1*1201 | L | V |
DRB1*1204 | L | D |
DRB1*1205 | L | V |
DRB1*1308 | L | D |
DRB1*1364 | L | D |
DRB1*1401 | F | A |
DRB1*1405 | F | D |
DRB1*1407 | F | A |
DRB3*0101 | F | V |
DRB3*0301 | F | V |
DQB1*0201 | I | A |
DQB1*0203 | I | D |
- In class II MHC molecules, a hydrophobic residue at β37 ensures a hydrophobic residue at β57 or else retains the strongly conserved aspartic acid. In the latter case a salt bridge is maintained between β57 Asp and the invariant α76 Arg which is thereby "latched." A hydrophobic β37 when coupled with a replacement of β57 makes the P9 pocket hydrophobic and tends to move α76 Arg out of the pocket as in DR52a or in DQ2. This mollifies diabetes association and explains the neutral association of DRB1*12 and DRB3*0101. Hydrophobic β37 is proposed as the basis of resistance to type 1 diabetes.
