Calmodulin regulates dimerization, motility, and lipid binding of Leishmania myosin XXI.

Myosin XXI is the only myosin expressed in Leishmania parasites. Although it is assumed that it performs a variety of motile functions, the motor's oligomerization states, cargo-binding, and motility are unknown. Here we show that binding of a single calmodulin causes the motor to adopt a monomeric state and to move actin filaments.

Cloning, expression, and characterization of a novel molecular motor, Leishmania myosin-XXI.

The genome of the Leishmania parasite contains two classes of myosin. Myosin-XXI, seemingly the only myosin isoform expressed in the protozoan parasite, has been detected in both the promastigote and amastigote stages of the Leishmania life cycle. It has been suggested to perform a variety of functions, including roles in membrane anchorage, but also long-range directed movements of cargo.

Molecular architecture: construction of self-assembled organophosphonate duplexes and their electrochemical characterization.

Self-assembled monolayers of phosphonates (SAMPs) of 11-hydroxyundecylphosphonic acid, 2,6-diphosphonoanthracene, 9,10-diphenyl-2,6-diphosphonoanthracene, and 10,10'-diphosphono-9,9'-bianthracene and a novel self-assembled organophosphonate duplex ensemble were synthesized on nanometer-thick SiO(2)-coated, highly doped silicon electrodes. The duplex ensemble was synthesized by first treating the SAMP prepared from an aromatic diphosphonic acid to form a titanium complex-terminated one; this was followed by addition of a second equivalent of the aromatic diphosphonic acid. SAMP homogeneity, roughness, and thickness were evaluated by AFM; SAMP film thickness and the structural contributions of each unit in the duplex were measured by X-ray reflection (XRR).