Circular dichroism cuvettes

Circular dichroism spectra - Spectra were recorded on a Jasco J-600 spectropolarimeter at room temperature. Far UV CD spectra (190 to 260 nm) of 7.5 nM peptide calmodulin complex in 25 mM Tris, 100 mM KCl and 1 mM CaClj were measured in a 0.1 cm path length cuvette. Near UV CD spectra (250 to 340 nm) of 20 /iM peptideicalmodulin complex in the same buffer were measured in a 1 cm path length cuvette. 

As determined from HPLC, the purity of the peptide was greater than 90%. Steady-state fluorescence spectra of this peptide were collected from 310-480 nm with an excitation wavelength of 264 nm. A 1 cm pathlength cuvette was used with concentrations of 8.6 pM. The emission quantum yields were determined relative to N-acetyl-L-tryptophanamide at pH = 6.9 (f = 0.13) (17). Steady-state circular dichroism spectra were obtained using a 0.5 mm pathlength cylindrical cell and concentrations of 0.26 mM. The mean molar ellipticity [0] (deg cm dmol" ) was calibrated with (+)-10-camphorsulfonic acid. Concentrations of the solutions were determined by measuring the absorbance of 4-methylaminobenzoic acid. 

Circular dichroism (CD) spectra were recorded on an Olis RSM spectropolarimeter at room temperature, in a 2 mm path cuvette. Ellipticity is expressed in millidegrees. 

Fig. 13. Circular dichroism spectra of transketolase in 20 mM sodium phosphate buffer containing 10 mMNa2S04, pH 7.2. 0.5 cm cuvettes were used. The reconstitution was carried out at 25 0.1 °C.

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