It's embarrassing for me to ask this but well such is life. NIMH Psychoactive Drug Screening Program (PDSP) Ki Database is mentioned as the source of the average binding affinity (Ki) values given in Goodman and Gilman but whenever I try to, in some way, confirm that these values are averages obtained from PDSP I get values that are way (up to 10,000 fold) off the values given in Goodman and Gilman. (ps. I am a mathematician too so I know how to take an average, $\bar{x} = \frac{\sum_i^n x_i}{n}$ so you don't need to hold my hand through the calculation with something as simple as the conventional definition of averages) Therefore I have reached the conclusion that I must be doing the calculations wrong. Please show me how to do them correctly. Here's a screenshot of exactly what Goodman and Gilman says that's confusing me:

enter image description here enter image description here

Oh and yes I am using just the cloned human transporter values not just all the stuff that comes up.

  • $\begingroup$ check the units.. may be a μM to nM conversion problem.. verify $\endgroup$
    Apr 30 '13 at 4:51
  • $\begingroup$ Nope, all the units are nM. $\endgroup$
    – Josh Pinto
    Apr 30 '13 at 5:14
  • $\begingroup$ it would be better if you can save this page as a document or pdf and put it in dropbox. Or if there is an ebook then please provide the url if it is possible. $\endgroup$
    Apr 30 '13 at 8:50
  • $\begingroup$ The latter would be a breach of copyright and the other I don't quite understand how that would be better. $\endgroup$
    – Josh Pinto
    Apr 30 '13 at 8:55
  • $\begingroup$ Sharing the URL: if it is open such as in the books in the NCBI site. Better: so that i dont need to zoom in to see. $\endgroup$
    Apr 30 '13 at 10:24

Since I asked this question I found out what I was doing wrong in searching for Ki (i.e. I thought the Ki ID was the test ligand and hence I was searching for drugs the wrong way) values but also how, I think Goodman and Gilman got its Ki values.

I think what they did was they searched for the hot ligand that gave the most consistent and numerous Ki values and took the average of the consistent Ki values (with an relative tolerance of ~100% between results). Additionally since I knew the data, as is stated in the page displayed above, was taken 30 June 2009 I was able to eliminate some sources that were probably not available on PDSP at the time. Using this I was able to get consistent averaged Ki values in the vast majority of cases (with like, at most a small handful of exceptions).


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