HYBRID LIPOSOMES COUPLED TO STERIC CONTROL WITH HIGH ENANTIOSELECTIVITY

With respect to the hydrolysis of enantiomeric substrates (p-nitrophen yl N-dodecanoyl-D(L)phenylalaninate; C-12-D(L)-Phe-PNP) by the tripept ide catalyst loxycarbonyl)-L-phenylalanyl-L-histidyl-L-leucine; Z-PheH isLeu), a remarkably high enantioselectivity (k(a/obsd)(L)/k(a/obsd)(D ) = 28) along with marked rate-enhancement of the hydrolytic cleavage of C-12-D(L)-Phe-PNP was obtained with specific coaggregates of 32 mol % L-alpha-dipalmitoylphosphatidylcholine (DPPC) and 68 mol % 1,1,3,3- tetramethylbutyl)phenyl]-omega-hydroxypoly (oxy-1,2-ethanediyl)(Triton X-100). Tile enantioselectivity was maximized at the phase transition temperature (T-e) in the 65 mol % DPPC/35 mol % TrixonX-100 and 32 mol % DPPC/68 mol % TritonX-100 coaggregate systems. The hydrophobicity a nd fluidity of the coaggregates can apparently be changed around T-e o n tile basis of isokinetic temperature and fluorescence parameter stud ies.