Arrhenius plots ofthe activity of small subunit adenosine deaminase (ADA) free in solution and bound to its complexing protein ( ADCT) are linear over the temperatute range 7-37'C and exhibit similar energy of activation (Ha) On the contrary. ADA bound to ADC'P reconstituted in DM PC liposomes exhibits an Ai rhenius plot \\ilh Uvo breaks at 25'C and l.VC. \ieldiny; lliiee neailv parallel lines at the range of 37-27'C, 25-15C and Li-7'C, u it h no diatiue in tlie apparent lia I-'uithcrmore. at each of these discontinuities a .iO% increase in ADA activity is observed These results could rise from an ouuvard vertical displacement of AIX'P-ADA complex from the hpid core, mediated by the main phase and pre-phase transitions at 23!C and 1.VC, respectively These results are supported by simulated Arrhenius plots based on a model tot the dependence of active site accessibilitv on lipid "microvLicosilv", mediated by lenipetatuix'.
|State||Published - 1 Dec 1997|
ASJC Scopus subject areas
- Molecular Biology