Table 4.
Contribution of different amino acids to the elevation of crystallin refractive indices
| amino acid | (dn/dc)a (ml/g)(1) | normalized dn/dc contribution of each amino acid (%)(2) | ||
|---|---|---|---|---|
| γ B(3) | γM (4) | Lops22 (5) | ||
| Pro | 0.166 | 3.6 (2.9) | 6.5 (2.0) | 5.3 (2.2) |
| Ala | 0.167 | 9.5 (7.7) | 8.2 (2.9) | 4.3 (1.3) |
| Ser | 0.170 | 1.3 (1.0) | −3.6 (−4.2) | 5.6 (2.2) |
| Thr | 0.172 | 5.8 (4.3) | 8.3 (2.5) | 5.2 (1.7) |
| Val | 0.172 | 8.5 (6.5) | 6.6 (1.4) | 7.0 (2.9) |
| Leu | 0.173 | 4.8 (3.5) | 15.9 (7.4) | 14.0 (7.9) |
| Gly | 0.175 | −0.7 (−0.5) | −1.5 (−3.0) | 0.5 (−1.5) |
| Ile | 0.179 | −1.2 (−0.8) | 3.5 (−0.8) | 3.9 (0.3) |
| Lys | 0.181 | 8.5 (5.0) | 8.1 (0.8) | 1.6 (−1.0) |
| Glu | 0.183 | 1.1 (0.6) | 5.8 (−0.5) | 4.3 (0.0) |
| Gln | 0.186 | −0.9 (−0.2) | 2.1 (−2.0) | 4.6 (−0.7) |
|
| ||||
| Asn | 0.192 | −0.4 (0.1) | −3.6 (−1.8) | −3.7 (−1.1) |
| Asp | 0.197 | − 0.4 (1.2)
|
−1.1 (−1.7) | −0.8 (−0.9)
|
| Met | 0.204 | 1.1 (3.1) | −3.2 (6.0) | 1.5 (12.6) |
| Arg | 0.206 | 5.5 (11.7) | −1.2 (3.0) | 0.6 (1.9) |
| Cys | 0.206 | 1.1 (2.7) | −0.5 (−0.1)
|
0.3 (0.2) |
| His | 0.219 | −1.5 (−2.2) | 1.0 (0.9) | −1.8 (−5.4) |
| Tyr | 0.240 | 38.2 (42.4) | 18.2 (2.2) | 25.7 (30.1) |
| Phe | 0.244 | −3.5 (−4.5) | 5.3 (6.4) | 8.7 (10.1) |
| Trp | 0.278 | 15.7 (18.1) | 16.7 (19.3) | 7.9 (8.0) |
Calculated for a hypothetical poly-peptide of that amino acid.
Difference between the dn/dc calculated from the protein sequence (dn/dc)P and a sequence where the relative abundance of amino acid X is changed to that of average proteins (dn/dc)PXavg, normalized by the total difference (dn/dc)P – 0.190 ml/g. The values in parenthesis are the difference between (dn/dc)avgXP of an average protein with relative abundance of X set to that in crystallin minus 0.190, normalized by the total difference (dn/dc)P – 0.190 ml/g.
human γB crystalline (NP_005201).
Mexican tetra γM-crystallin (AAF07205).
squid S-crystallin (AAB01057). The solid horizontal line separates amino acids with lower than average from those with higher than the dn/dc of average proteins. The horizontal lines in the columns of the individual proteins similarly separates the amino acids lower and higher relative to the dn/dc of that crystallin.