Processive Catalysis

Processive catalysis.

Nature's enzymes are an ongoing source of inspiration for scientists. The complex processes behind their selectivity and efficiency is slowly being unraveled, and these findings have spawned many biomimetic catalysts. However, nearly all focus on the conversion of small molecular substrates. Nature itself is replete with inventive catalytic systems which modify, replicate, or decompose entire p...

Why kinesin is so processive.

Kinesin I can walk on a microtubule for distances as long as several micrometers. However, it is still unclear how this molecular motor can remain attached to the microtubule through the hundreds of mechanochemical cycles necessary to achieve this remarkable degree of processivity. We have addressed this issue by applying ensemble and single-molecule fluorescence methods to study the process of...

Homogeneous Catalysis Homogeneous Catalysis

Coupling of Two Non-processive Myosin 5c Dimers Enables Processive Stepping along Actin Filaments

Myosin 5c (Myo5c) is a low duty ratio, non-processive motor unable to move continuously along actin filaments though it is believed to participate in secretory vesicle trafficking in vertebrate cells. Here, we measured the ATPase kinetics of Myo5c dimers and tested the possibility that the coupling of two Myo5c molecules enables processive movement. Steady-state ATPase activity and ADP dissocia...

The levansucrase and inulosucrase enzymes of Lactobacillus reuteri 121 catalyse processive and non-processive transglycosylation reactions.

Bacterial fructosyltransferase (FTF) enzymes synthesize fructan polymers from sucrose. FTFs catalyse two different reactions, depending on the nature of the acceptor, resulting in: (i) transglycosylation, when the growing fructan chain (polymerization), or mono- and oligosaccharides (oligosaccharide synthesis), are used as the acceptor substrate; (ii) hydrolysis, when water is used as the accep...