JBC, Vol. 252, Issue 12, 4319-4325, Jun, 1977
Effects of colipase on hydrolysis of monomolecular films by lipase
R. Verger, J. Rietsch and P. Desnuelle
In a system free of bile salts we measured lipase hydrolysis of
1,3-didecanoylglycerol films in the presence or absence of colipase at
different surface pressures. The strong, but not absolutely specific
protective effect of colipase, most visible at low surface pressure, can
account for the higher enzyme activity in the presence of colipase. This
can be understood by taking into account simultaneous penetration and
surface inactivation fluxes. Using radioactively labeled lipase, we have
shown for the first time in a bile salt-free system that the critical
surface pressure above which lipase can no longer penetrate a
1,2-didodecanoylphosphatidylglycerol monlayer is around 23 dynes/cm.
Colipase increased this critical surface pressure to 30 dynes/cm indicating
that it enables lipase penetration between 23 and 30 dynes/cm. The transfer
experiment showed that colipase acts by first penetrating the lipid film
and then serving as an anchor for lipase into the film.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
