Question

My understanding is that hydrogen bonds formed by proteins require the NH2 / COOH to be neutral. Hence to find out when the hydrogen bonds are the strongest will depend on the absolute charge of the protein and not the net charge. Hence how do you calculate this absolute charge or is there another way to determine when the strongest hydrogen bonds will be formed when changing the pH condition?

Answer 1

The strength of hydrogen bonds in proteins is affected by the pH, which influences the protonation states of amino acids. At the isoelectric pH, a protein has no net charge, facilitating maximized hydrogen bonding in neutral amine and carboxyl groups. An absolute charge calculation is impractical; focus on individual group protonation at certain pH levels is key.

Step-by-step explanation:

The strength of hydrogen bonds in proteins can be influenced by the pH of the environment because pH affects the protonation states of amino acids.

At the isoelectric pH, the molecule has no net charge because the positive and negative charges are balanced. However, the absolute charge of a protein is more difficult to define, as it would involve accounting for all individual charges without considering their signs.

Hence, determining the points of strongest hydrogen bonding involves understanding the pKa values of the amino acids in the protein structure and the pH at which these functional groups are likely to be in their neutral state.

It is not practical to calculate an 'absolute charge', but rather one should consider the presence of neutral amino and carboxylic acid groups which are able to form hydrogen bonds.