The Sugar Model: Catalytic Flow Reactor Dynamics of Pyruvaldehyde Synthesis from Triose Catalyzed by Poly-L-Lysine Contained in a Dialyzer

摘要

The formation of pyruvaldehyde from triose sugars was catalyzedby poly-L-lysine contained in a small dialyzer with a 100molecular weight cut off (100 MWCO) suspended in a much largertriose substrate reservoir at pH 5.5 and 40 °C. Thepolylysine confined in the dialyzer functioned as a catalyticflow reactor that constantly brought in triose from thesubstrate reservoir by diffusion to offset the drop in trioseconcentration within the reactor caused by its conversion topyruvaldehyde. The catalytic polylysine solution (400 mM, 0.35mL) within the dialyzer generated pyruvaldehyde with a syntheticintensity (rate/volume) that was 3400 times greater than that ofthe triose substrate solution (12 mM, 120 mL) outside thedialyzer. Under the given conditions the final yield ofpyruvaldehyde was greater than twice the weight of thepolylysine catalyst. During the reaction the polylysine catalystwas poisoned presumably by reaction of its amino groups withaldehyde reactants and products. Similar results were obtainedusing a dialyzer with a 500 MWCO. The dialyzer method ofcatalyst containment was selected because it provides a simpleand easily manipulated experimental system forstudying the dynamics and evolutionary development of confinedautocatalytic processes related to the origin of life underanaerobic conditions.