Enzymatic trimethylation of lysine-72 in cytochrome c.

The research revolves around the study of the physicochemical mechanism related to protein-lysine methylation. It elaborates on how the enzymatic methylation of lysine-72 in horse heart cytochromes c affects its electrophoretic characteristics or pI values.

Objective

This research study intends to understand how the enzymatic methylation of lysine-72 in horse heart cytochromes c affects their electrophoretic behavior or pI values, especially when compared to chemical modifications using trifluoromethylphenylcarbamoyl (neutral group) or carboxydinitrophenyl (acidic group).

Method

• Scientific analysis followed the comparison of pI values of two chemically modified horse heart cytochromes c (modified with trifluoromethylphenylcarbamoyl and carboxydinitrophenyl) with the enzymatically methylated cytochrome c.

Findings

• The study found that although both chemically modified cytochromes have lower pI values than the unmodified cytochrome c, enzymatic methylation proved more efficacious in reducing the pI values of the protein than the chemical modification.
• The lowering of the pI value of cytochrome c via enzymatic methylation is heavily reliant on the urea concentration. An increase in the urea concentration results in a reduction of the methylation effect on the protein molecule, causing the difference in pI values to almost vanish.
• The concentration of urea, when increased to 6M, disrupts the protein tertiary structure, which essentially nullifies the methylation’s impact on the protein.

Implication

• The research provides insights into protein-lysine methylation mechanisms. It mainly shows that enzymatic modification is a more efficient method in lowering pI values of proteins than chemical modifications. It also affirms the role of urea concentration in the efficiency of protein methylation.