WOOL AS AN INDICATOR OF XEUROPHARMACOLOGICAL ACTIVITY 81 



tins, allow me to refer to the following tabulation: 



Molecular Ratio 



Type of Keratin 



Histidine : Lysine : Arginine 1:2:2 Neurokeratin 



Histidine : Lysine : Arginine 1:4:4 epidermal keratin/ 



Histidine: Lysine: Arginine 1:4:12 a-keratin 



soft 



hard 



Dr. Jordi Folch-Pi (McLean Hospital, Waverly, Mass.): Dr. Fischer, why- 

 did you not do that with neurokeratin which can be prepared quite easily? 



Dr. Fischer: I have no access to it. I am very sorry. 



Dr. Folch-Pi: Prepare it. 



Dr. Fischer: Wool was chosen for other reasons. In 1946-47 I began to 

 use wool as a model for bacteria. I have found since that there is a relationship 

 between the affinity of water soluble substances for wool and their bactericidal 

 activity against vegetative cells of certain bacteria. A further relationship 

 between bactericidal activity and Gram-staining behavior was then expressed 

 quantitatively and indicated, among other things, that the similarity in be- 

 havior between gram-negative, gram-variable, and gram-positive bacteria on 

 the one hand and intact wool, medium-alkali-degraded wool and highly-alkali- 

 degraded wool on the other, apparently is caused by some structural feature 

 common to the wool and the bacterial cytoplasmic membrane. 



Dr. Folch-Pi: Neurokeratin is very easy to prepare and the way to prepare 

 it is very similar to the way in which wool is normally treated. It is defatted 

 and treated with alkali and then you do not have to spend hours justifying 

 why you think that the neurons are covered by a sweater. 



Dr. Fischer: If one treats wool with alkali then one obtains alkali-degraded 

 wool with broken disulfide linkages and free aldehyde groups, etc.; we have 

 found the affinity of compounds towards such wools quite different from that 

 which they display to intact (undamaged) wool. In our experiments we use 

 defatted wool which has been equilibrated with diluted acetic acid at pH 4.9, 

 the isoelectric point of the wool. 



Dr. Folch-Pi: What we call neurokeratin, the composition which you are 

 quoting, has been obtained by that method. Therefore, any similarity that you 

 claim between your undenatured wool and the neurokeratin would not be 

 supported by the very thesis you are putting forth. You could prepare it by 

 milder methods. 



Dr. Fischer: Would it be the same? 



Dr. Folch-Pi: You could skip the alkali because neurokeratin is not con- 

 sidered a keratin chemically. In a recent paper it was pointed out that while 

 both might have similar, if not identical, amino acid composition there are 

 certain differences such as the location of groups. 



Dr. Fischer: There is an unusually high amount of sulphur present in wool 



