[Some physicochemical properties of native and polymerized glutaraldehyde-treated horse heart cytochrome c].

This research article explores the impact of glutaraldehyde treatment on the properties of horse heart cytochrome c. The treatment doesn’t affect the absorption but causes polymerization, influencing its pI shifts, kinetic parameters, and immunochemical variances.

Impact of Glutaraldehyde Treatment on Cytochrome c Absorption

• The study finds that treating horse heart cytochrome c with glutaraldehyde does not alter its ability to absorb either in visible or in UV spectra. The absorption properties of cytochrome c, a heme protein involved in electron transport chain, remains the same post the treatment.

Formation of Polymeric Forms of Cytochrome c

• Another key finding of the study is that glutaraldehyde treatment leads to the formation of dimers, trimers, and high-polymeric forms of cytochrome c. Here, a dimer refers to a molecule or molecular complex formed by the combination of two like molecules; a trimer, similarly, involves the combination of three like molecules. High-polymeric forms mean larger molecular structures formed by repeating subunits.

Shifts in pI of Cytochrome c

• The research also notes that glutaraldehyde treatment shifts the pI (isoelectric point) of all cytochrome c fractions towards more acidic pH. This indicates that the treatment affects the electric charge of the cytochrome c molecules, making them more prone to interact with acidic substances.

Changes in Kinetic Parameters of Cytochrome c

• Glutaraldehyde polymerization significantly changes the kinetic parameters of the cytochrome c benzidine reaction. The treatment leads to an increase in the protein’s affinity for 3,3-diaminobenzidine, a chemical commonly used as a dye.
• Simultaneously, there’s a decrease in the effectiveness of H2O2 (hydrogen peroxide) binding. This can have various implications for biochemical reactions in which these compounds are involved.

Immunochemical Differences

• The biochemical changes caused by glutaraldehyde treatment, such as the shift towards more acidic pH, can be associated with immunochemical differences of native and treated cytochrome c. This means that the natural (native) and the treated versions of the protein may have different abilities to stimulate an immune response.