Table 2.
Contact residues of the α1β2 interface of various hemoglobin states
| Contact | CO bovine (R) | Met horse (R) | CO human (R) | Oxy human (R) | Met pig (R) | CO human (R2) | Dxy human (T) | |
| Switch region | ||||||||
| α1Thr38(OH) | − β2His97(O) | 3.8 (6.3) | 4.3 (5.4) | 2.8 (5.2) | 3.2 (5.2) | 4.9 (5.3) | 5.7 (7.0) | 9.9 (8.9) |
| α1Thr41(OH) | −β2His97(NH) | 3.7 (7.8) | 3.8 (7.4) | 3.7 (7.2) | 4.0 (7.3) | 3.1 (7.1) | 5.3 (9.5) | 7.0 (4.7) |
| α1Pro44 | −β2His97 | (13.1) | (13.0) | (12.8) | (12.6) | (12.3) | (14.8) | (7.2) |
| α1Thr38(OH) | −β2Asp99(N) | 5.6 (8.3) | 5.0 (7.0) | 4.2 (6.7) | 4.3 (6.9) | 4.7 (6.5) | 7.5 (9.5) | 5.6 (6.1) |
| α1Tyr42(OH) | −β2Asp99(ODI) | 7.6 (12.8) | 8.6 (12.7) | 8.5 (12.7) | 8.5 (12.7) | 7.9 (12.2) | 9.4 (13.9) | 2.5 (7.8) |
| Intermediate region | ||||||||
| α1Val96 | −β2Asp99 | (7.8) | (8.0) | (8.3) | (8.0) | (8.0) | (7.6) | (10.1) |
| α1Asn97(ND2) | −β2Asp99(ODI) | 5.8 (9.1) | 5.0 (8.9) | 4.7 (9.0) | 4.7 (9.0) | 4.2 (8.7) | 7.2 (9.5) | 2.8 (9.4) |
| α1Asp94(OD2) | −β2Asn102(ND2) | 2.8 (9.2) | 2.9 (9.2) | 3.0 (9.0) | 2.8 (9.2) | 2.8 (9.4) | 2.8 (9.2) | 5.7 (8.1) |
| α1Thr41(O) | −β2Arg40(NH2) | 3.1 (11.4) | 3.4 (11.0) | 2.9 (10.2) | 3.4 (10.4) | 5.1 (11.3) | 3.5 (11.5) | 4.8 (12.0) |
| Joint region | ||||||||
| α1Arg92(NH2) | −β2Gln39(OEI) | 3.0 (7.5) | 4.2 (7.9) | 2.9 (8.0) | 3.2 (7.8) | 4.9 (8.4) | 4.4 (7.5) | 4.5 (8.5) |
| α1Arg92 | −β2Glu43a | (10.6) | (11.5) | (11.9) | (11.3) | (11.0) | (10.9) | (12.5) |
| α1Asp94(ODI) | −β2Trp37(NE1) | 3.8 (5.5) | 3.7 (5.6) | 3.5 (5.6) | 3.5 (5.7) | 3.6 (5.4) | 3.7 (5.4) | 3.0 (7.1) |
Values in parentheses are the Ca–Ca distances. In the structures with a tetramer in the asymmetric unit, the contact distances shown are those between the α1β2 interface. Similar contact distances are also observed at the α2β1 contact region. Distances are in Å.
aIn horse hemoglobin, Glu43 is Asp43.