Researches on the nature of enzyme-action. I, On the causes of the rise in electrical conductivity under the action of trypsin / by W.M. Bayliss.

  • William Bayliss
Date:
[1907?]
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Licence: Public Domain Mark

Credit: Researches on the nature of enzyme-action. I, On the causes of the rise in electrical conductivity under the action of trypsin / by W.M. Bayliss. Source: Wellcome Collection.

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    are acted upon by various precipitants of basic bodies. I find that this is the case when gelatin is precipitated by tannin’. So that all the calcium would be found in the filtrate in both cases. This method being found of no value for the purpose I tried two different ones. In the first place, on the assumption that chlorine would be one of the components of the ash constituents, I estimated the change of concentration of Cl~ ions by a concentration battery of the kind already described : 100 grms. of 15 °/, gelatin+1 c.c. ‘ NaOH+1 grm. trypsin at 38° for eight days. Neutralized by addition of 1 c.c. ; H,SO,. Placed in one calomel electrode, the other containing 7 KCl. The z.m.r. found was 0:1363 volt. Calculating by Nurnst’s formula the concentration (as KCl) of the chlorides of the gelatin, assuming complete dissociation in the digest and 0°68 dissociation of the normal KCl, the value comes out to be ia or 0°068 °/,. A similar preparation in which the trypsin had previously been heated to 100° gave u.M.F, 0°1415 or as KCl 730 = 0058 Jy: In this experiment there was evidence, therefore, of an increase of chlorine ions corresponding to 0:01°/, of KCl. But I would not lay much stress on this result, since the solutions were of a complex nature and there is some uncertainty as to the actual process at the electrode. In the second place I have made some experiments by filtration of digested and undigested gelatin through Martin’s gelatin filter?. For this purpose I used D’Arsonval’s apparatus for sterilization by means of liquefied carbon dioxide. The brass tube, into the lower end of which was screwed the porcelain candle impregnated with gelatin and treated with formalin, was filled with the solution to be filtered and connected at the top to a cylinder containing liquid carbon dioxide. By this means the pressure was kept continuously at about 50 atmospheres until sufficient filtrate had been collected. In the case of the undigested gelatin it was necessary to keep the tube warm by surrounding it with a coil of pipe through which a current of water warmed to about 50° C. was allowed to flow. It was not found that the filtrate contained any considerable amount of dissolved carbon dioxide, not sufficient to come off in bubbles ; this was perhaps due to the fact that there was a layer of toluene on the surface of the liquid in the filter which prevented easy 1 «¢ Adsorption phenomena,” loc. cit. p. 209. 2 This Journal, xx. p. 364. 1896. See also Reid, This Journal, xxvu. p. 161. 1901, and Craw, Proc. Roy. Soc. B. uxxvit. p. 311. 1905.
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