To what extent "modern" geometric restraints have been upgraded over
original Engh&Huber? And where I can find a consensus set of values
(with variances)?
For example, Fisher et al., Acta D68:800 discusses how histidine angles
change with protonation, and refers to Engh&Huber when it says that
ND1-CE1-NE2 goes from 111.2 to 107.5 when histidine acquires positive
charge (Fig.6). But angle table (Table 3) in original Engh&Huber from
1991 does not have any 107.5 value and seems to suggest that the numbers
should rather be 111.7+-1.3 and 108.4+-1.0, respectively.
I understand that these values are derived from structural databases and
thus can be frequently updated. Is there some resource where "most
current" values would be listed?
Cheers,
Ed.
--
After much deep and profound brain things inside my head,
I have decided to thank you for bringing peace to our home.
Julian, King of Lemurs
|