Which brings up something about PISA. If I run PISA on pdb entry 2IE3,
which I'm familiar with, I get the following numbers from PISA and
CCP4's AREAIMOL (surface areas in Angstrom^2) for the A:C interface.
>> PISA for 2IE3
Automatic A:C interface selection 907.9
(a crystal packing interface is larger than this, but this surface
is the A:C interface)
>> AreaIMol with some editing of 2IE3 to separate the chains
Chain A 25,604.4
Chain C 11,847.4
Total 37,451.8
Chain AC 35,576.6
Difference 1,875.2
Difference/2 937.6
For buried S.A. I agree with Steve Darnell's definition. However PISA
appears to be reporting half that value, or what it calls "interface
area". Potentially confusing.
Phil Jeffrey
Princeton
Steven Darnell wrote:
Sorry, that equation should read:
Buried_Surface_Area = ASA_unbound1 + ASA_unbound2 - ASA_bound
ASA = Accessible Surface Area
The way I wrote it before would give you a negative value.
Regards,
Steve Darnell
