Cytochrome sedimentation constant

The molecular weight of cytochrome c peroxidase has been determined to be 34,100 on the basis of a sedimentation constant of 3.55 S, a diffusion constant of 9.44 F, and a partial specific volume of 0.733 ml/g (4 )-The enzyme exists as a monodisperse monomer containing one ferric protoporphyrin IX, which is noncovalently bound (/, , 14). No other transition metal is detected in crystalline preparations of the enzyme (22). The apoenzyme moiety is an acidic protein with an isoelectric point at pH... 

Perhaps the strongest evidence in favor of the theory that the cytochrome oxidase system is composed of a single protein comes from the physicochemical studies of Takemori. Purified cytochrome oxidase appears in the ultracentrifuge as a nondispersed protein (sedimentation constant = 21.9 diffusion constant =3.58 x 10 partial specific volume = 0.72). The molecular weight of the protein was calculated on the basis of these studies and was found to equal 530,000. 

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