Transition between single-headed and double-headed binding of kinesin

Equilibrium and transition between single- and double-headed binding of kinesin as revealed by single-molecule mechanics.

Kinesin is a processive motor protein that "walks" on a microtubule toward its plus end. We reported previously that the distribution of unbinding force and elastic modulus for a single kinesin-microtubule complex was either unimodal or bimodal depending on the nucleotide states of the kinesin heads, hence showing that the kinesin may bind the microtubule either with one head or with both heads...

Energetics of the single-headed kinesin KIF1A.

KIF1A is a single-headed molecular motor that moves processively and unidirectionally along a microtubule by using the chemical energy released by hydrolyzing adenosine triphosphate (ATP) into adenosine diphosphate (ADP) and inorganic phosphate (P(i)). Although the movement of KIF1A seems to have successfully been explained by a simple Brownian motor model of the flashing ratchet type, this mod...

A double-headed polyp

A 50-year-old man was seen as an outpatient for isolated, minimal and intermittent lower gastrointestinal bleeding. He had a history of well-controlled hypertension and diabetes. During his colonoscopy, a polyp with two heads that shared a common long and large stalk was encountered in the sigmoid colon (Fig. 1A). The heads were approximately 2 cm and 3 cm in size. Because of their overall size...

A Double-Headed Monster

A Double-Headed Monster

A double-headed monster was born in the Railway Hospital, Samastipur, on 5th July, 1948. It is an interesting case because of its rarity; the photograph (plate XXII) tells its own story. Dr. Mody, in his jurisprudence, gives a picture of such monster without any detail. The woman was a sweeper by caste, second para, and fairly well built. She came to hospital in a precarious condition, having b...