How can I find the denaturing/breaking temperature of a molecule?

[Tanarif]

So essentially, I'm trying to find the temperature at which growth hormone (GH) denatures. I've got a box of it and it says "refrigerate at between 2'C to 9'C". I'm keeping it at room temperature (it's not for use atm), but would like to find out how to know at what temperature GH would break up.

I know GH is made of 191 amino acids, and there's more info on the wiki: https://en.wikipedia.org/wiki/Growth_hormone
Is there like a info sheet I can refer to find the denaturing point of a molecule?

Generally not entirely sure how to go about this, so any help is much appreciated!

 

[aroc91]

I found an article on it, but I don't have access to it.

http://onlinelibrary.wiley.com/doi/10.1002/jps.21386/full

Even so, I came across denaturation temperatures of other proteins like collagen and depending on the state (solid or reconstituted), the temp. can range from 42*C to over 150*C. I would expect GH to be stable at and below physiologic temperature based on that.

 

[Tanarif]

I found an article on it, but I don't have access to it.

http://onlinelibrary.wiley.com/doi/10.1002/jps.21386/full

Even so, I came across denaturation temperatures of other proteins like collagen and depending on the state (solid or reconstituted), the temp. can range from 42*C to over 150*C. I would expect GH to be stable at and below physiologic temperature based on that.

Cheers for that, I've bookmarked it and will purchase and give it a read in a week or two when I'm off from exams. I'll send it over if you're interested.

Collagen and GH are fairly differing in structure, no? It seems about right for collagen as I would imagine it to be a bigger in structure and thus be fair bit stronger too.

 

[Mike H]

Drug and protein formulation can be a subtle science. You don't mention what form the growth hormone is in - solution or solid? The paper linked to above focuses on freeze-dried preparations.

One thing to keep in mind is that activity is generally not guaranteed if not stored under the stated conditions. The case I always remember is that of using light scattering to see whether or not that insulin formulation is too old or stored under undesirable conditions. The proteins haven't fallen apart by any standard, but the desired activity is not maintained.