Modeling Smooth Muscle Myosin's Two Heads: Long-Lived Enzymatic Roles and Phosphorylation-Dependent Equilibria

Modeling smooth muscle myosin's two heads: long-lived enzymatic roles and phosphorylation-dependent equilibria.

Smooth muscle myosin has two heads, each capable of interacting with actin to generate force and/or motion as it hydrolyzes ATP. These heads are inhibited when their associated regulatory light chain is unphosphorylated (0P), becoming active and hydrolyzing ATP maximally when phosphorylated (2P). Interestingly, with only one of the two regulatory light chains phosphorylated (1P), smooth muscle ...

How phosphorylation controls the self-assembly of vertebrate smooth and non-muscle myosins.

Vertebrate non-muscle and smooth muscle myosin molecules, like almost all other myosins, have two heads, each of which carries an essential and a regulatory light chain. The rest of the molecule forms a rod-like tail, and it is these tails which are responsible for the self-assembly of myosin at physiological ionic strength to form filaments. The heads project from the resulting filaments, form...

Supports Force and Motion Phosphorylated on One of Its Two Heads Smooth Muscle

Phosphorylation of smooth muscle caldesmon by calmodulin-dependent protein kinase II. Identification of the phosphorylation sites.

Smooth muscle caldesmon was phosphorylated by smooth muscle calmodulin-dependent protein kinase II. The extent of phosphorylation obtained was 5.65 mol of phosphate/mol of caldesmon. Phosphorylated protein was subjected to the complete trypsin proteolysis and the produced phosphopeptides were purified by C-8 reverse phase chromatography. Nine phosphopeptides were isolated and by amino acid sequ...

Modeling Computational Security in Long-Lived Systems

For many cryptographic protocols, security relies on the assumption that adversarial entities have limited computational power. This type of security degrades progressively over the lifetime of a protocol. However, some cryptographic services, such as timestamping services or digital archives, are long-lived in nature; they are expected to be secure and operational for a very long time (i.e., s...