Relationship between Interaction Energy and Melting Temperature

[sozo91]

Homework Statement

So this is not really a homework problem, but it is an academic-related problem which I want to solve.

Suppose in my current research position, I'm making synthetic Collagen heterotrimers, composed of A,B,C monomers, which form into a triple helix arrangement. Each monomer is composed of 10 amino acid X-Y-G motifs, where X and Y are arbitrary amino acids and G is glycine.

In experiments using Circular Dichroism, we can determine the melting temperature of A,B,C heterotrimers in solution (we can also make homotrimers of A,A,A or other combinations like A,A,B).

I ask, then, are there any relevant equations relating interaction energy (relating to interactions between amino acid units in each monomer) and melting temperature?

Homework Equations

The Attempt at a Solution

Here I will provide more detail. In our lab, we specifically incorporated only 4 different types of amino acids, Proline (P), Hydroxyproline (O), Arginine (R) and Glutamate (E) as possible X,Y candidates. From there we constructed five distinct units based on the unit's stability and occurrence in nature: PEG,PRG,EOG,ROG,POG.

Of the five, POG is the most frequent and it has been shown (both empirically and theoretically) that adding more POG to your collagen unit significantly adds to the stability of the Collagen triple helix.

So the lab devised an equation to compute interaction energy:
$${E(AB) + E(BC) + E(CA)} - 3.8* \sum {(POG)}$$

I don't really want to go into more detail, so I'll sum up.

What I want to do is revise this to reflect the stability we find in melting temperatures.

Any help will be greatly appreciated. Thanks.

 

[nate808]

Hello,

Thank you for sharing your research with us. It sounds like you are working on a very interesting project.

In terms of your question about the relationship between interaction energy and melting temperature, there are a few factors to consider. First, the stability of the collagen triple helix is dependent on the interactions between the amino acid units within each monomer, as well as the interactions between the monomers themselves. So, in order to accurately predict the melting temperature, we would need to take into account both of these types of interactions.

Additionally, the melting temperature of a protein is influenced by many factors, including the composition and sequence of amino acids, as well as environmental conditions such as pH and ionic strength. Therefore, it may not be possible to accurately predict the melting temperature based solely on interaction energy.

However, your equation that takes into account the stability of POG units is a good starting point. I would suggest incorporating other factors such as the stability of the triple helix structure and the effects of different environmental conditions into your equation. This could potentially give you a more accurate prediction of melting temperature.

I hope this helps and good luck with your research!