RK-Spectro Technical Note 58: Titration of Cytochrome c

Introduction

The objective of this note  is to demonstrate the performance of the titration accessory for titration of Cytochrome c (from horse heart). Cytochrome c is unfolded in Guanidine Hydrochloride and has a strong fluorescence, the aim of the titration is to study the dependence of the guanidine concentration on the fluorescence signal.
The acquisitions were made using a MOS-250 and can be adapted to other instruments. A 1 cm quartz cuvette is filled with 2 ml of 40 µM of Cytochrome c in water. Titration is made using 40 µM of Cytochrome c in Guanidine Hydrochloride 8M in syringe n° 1, syringe n°3 is used to precisely remove excess liquid to ensure constant volume in the cuvette.
The titration accessory has to be installed on the stopped-flow unit and the MOS-250 ready to be used.