(biochemistry) An abbreviation for kilodalton, also kDa
(pathology) An abbreviation for: Kawasaki disease (an inflammatory disease) and Kienböck's disease (an avascular disease characterized by necrosis in the lunate bone of the wrist)
In biochemistry, KD refers to the dissociation constant. It is a type of equilibrium constant that measures the propensity of the dissociation of a complex molecule into its subcomponents. It describes how tightly a ligand binds to a particular protein, or at which point the salt dissociates into its component ions. The mathematical definition of dissociation constant is as follows: KD = [A]x[B]y / [AxBy], where [A] and [B] are the concentratons of A and B subunits and [AxBy] is the concentration of the complex AxBy.
kD may also refer to the symbol used for unit, kilodalton (also, kDa). One kilodalton is equivalent to 1,000 daltons. Dalton is a measure of the weight of a hydrogen atom.
KD is also the abbreviation for certain diseases. Kawasaki disease, for instance, is abbreviated as KD. It is an inflammatory disease causing vasculitis and sometimes aneurysm in individuals suffering from it. It is characterized by inflamed blood vessels throughout the body.
Kienböck's disease, also abbreviated as KD, is a disorder of the wrist. It is characterized by an avascular necrosis in the lunate bone of the wrist.