Studies on the chemical structure of cytrochrome c

Gillies, Neil Eoin (1954) Studies on the chemical structure of cytrochrome c. PhD thesis, University of Glasgow.

Abstract

1. Cytochrome c was prepared from horse heart according to the method of Keilin and Hartree (1945). The material obtained was chromatographed on a column of the cation exchange resin Amberlite IRC-50, on which it separated into four fractions. The fastest moving; fraction was found to consist of an iron-free protein. The remaining three fractions comprised a small amount of reduced cytochrome c, the main bulk of the cytochrome c in the oxidised state, and three narrow bands of the acid-modified haem-protein. The oxidised cytochrome c was found to have a purity comparable with that of electrophoretically pure cytochrome c obtained by other workers. 2. A quantitative amino acid analysis of cytochrome c was carried out after hydrolysates of the protein were fractionated on columns of potato starch and Dowex 50, according to the techniques introduced by Moore and Stein (1951) and Stein and Moore (1948). 3. An investigation was made of the N-terminal residues of cytochrome c, using the technique of Sanger (1945). Apart from DHP-lysine only traces of the DWP derivatives of alanine, serine and glutamic acid were observed. It is concluded that these traces were derived from impurities in the cytochrome c preparation. It therefore appears that cytochrome c has no free N-terminal residues, and that it consists of a cyclic chain of amino acids. 4. An autoxidisable peptide, containing the haem prosthetic group, was isolated after digesting cytochrome c with pepsin according to the method of Tsou (1951a). 5. Valine was found to be the K-terminal residue of this peptide. Later experiments showed that leucine may be the next amino acid linked to the free amino group of the valine residue. 5. The peptide was partially hydrolysed by means of concentrated HOI at 37

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Adviser: G Leaf
• Keywords: Molecular biology, Biochemistry
• Date of Award: 1954
• Depositing User: Enlighten Team
• Unique ID: glathesis:1954-72865
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 11 Jun 2019 11:06
• Last Modified: 11 Jun 2019 11:06
• URI: https://theses.gla.ac.uk/id/eprint/72865