Some Relationships Between Coacervates 



and Enzymes 



E. MACOVSCHI 



Institute of Biochemistry, Academy of Sciences of the Rumanian People's Republic, 



Bucharest 



The first investigations of die relationship between coacervates and en2ymes 

 were begun recendy by A. I. Oparin and his colleagues [1-5]. These investi- 

 gations were aimed at elucidating the relationships between coacervates and 

 enzymes which were either incorporated in artificial coacervates or are present 

 in natural structures similar to coacervates. Investigations of other relationships 

 such as the influence of coacervate droplets on enzymic processes taking place 

 in the surrounding liquid, the action of enzymes on coacervates as such and the 

 introduction of enzymes present on artificial and natural structures, which are 

 afterwards introduced into coacervates, have been started in our laboratory. 



We began our study of the influence of dispersed droplets on enzymic re- 

 actions taking place in the surrounding liquid, with hydrophobic emulsions. 



By the use of emulsions of benzene, toluene and cyclobexane in aqueous 

 solutions of catalase [6-9] and polyphenol oxidase [10] with the appropriate 

 substrates, and also with an emulsion of lecithin in an aqueous solution of succinic 

 dehydrogenase [11] it has been shown that the presence of the emulsified phase 

 can affect the enzymic reactions in question, for example, by suppressing them. 

 It was found that the nature of the hpid-water interface which is formed during 

 emulsification plays an important part in the processes of absorption and inacti- 

 vation of the enzymes. Thus, the addition of a relatively insignificant quantity 

 (2%) of higher fatty acids or higher alcohols to the emulsified phase decreases 

 the inhibitory power of the emulsified phase, while, in the presence of cholesterol, 

 the enzymic reaction proceeds in almost the same way as it does in the absence 

 of the emulsified phase. 



This marked change in the properties of the lipid-water interface imder the 

 influence of higher fatty acids and alcohols and cholesterol was confirmed by 

 altering the permeability of these 'Uquid membranes' [12, 13] by means of the 

 droplet method which we have worked out [14, 15]. 



Coming to coacervates, and bearing in mind their hydrophilic character, it 

 might be expected, a priori, that they would show more complicated relation- 

 ships with enzymes than hydrophobic emulsions. 



Investigations of the action of urease on urea in the presence of a protamine- 

 gum arable coacervate [16] showed that, in both cases, the dispersed coacervate 

 drops slowed the course of the enzymic reaction. 



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