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Charge density on native and ultraviolet‐irradiated myosin A
Author(s) -
Westley Francis,
Kaldor George,
Cohen Irving
Publication year - 1966
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.1966.360040207
Subject(s) - myosin , chemistry , irradiation , electrophoresis , ultraviolet , charge density , molecule , ultraviolet light , diffusion , analytical chemistry (journal) , photochemistry , chromatography , optics , biochemistry , physics , nuclear physics , organic chemistry , thermodynamics , quantum mechanics
The axial ratios ( a / b ) of native and 60 min. ultraviolet‐irradiated myosin A molecules were calculated from previously reported sedimentation and diffusion data; values found were a / b = 74, a = 1880 A., and b = 26 A. for native myosin A; a / b = 104, a = 3280 A., and b = 32 A. for 60 min. ultraviolet‐irradiated myosin A. Electrophoretic mobilities gave identical values of 3.2 (±0.1) × 10 −5 cm. 2 /v.‐sec. for both native and 60 min. ultraviolet‐irradiated myosin A. From the prior sedimentation and diffusion data, together with newly obtained electrophoretic data, the net charge Z and the charge density σ of native and ultraviolet‐irradiated myosin A molecules were calculated from Henry's equation. The following results were obtained: for native myosin A, Z = 160 negative charges per molecule and σ = 22 coulombs/cm. 2 ; for ultraviolet‐irradiated myosin A, Z = 312 negative charges per molecule and σ = 20 coulombs/cm. 2 . The results of this study provide an experimental demonstration that, the electrophoretic mobility of charged solute particles is dependent upon the particle charge density and not on the absolute charge of the particle.