Proteins

[Adz795]

I have come across these terms: homodimer, heteromer, hexamer,etc. I don't quite understand what they mean. I would appreciate it if you could explain me in detail the significance of these terms. You may also do by just posting a link so that I'll read it myself. I couldn't find it online the relevant data related to these terms.

I also want to know what happens when proteins are treated with Mercaptoethanol, urea, etc.
Thank you.

[canalon]

Basically learn greek.
Homo: same
Hetero: different
di: 2
hexa: 6
Mer (actually not sure if the root is greek for that one): unit
Homo di mer: same 2 units is aprotein made of 2 identical subunits
Hetero di mer: 2 different units

[Adz795]

So with "-mer" you mean a subunit? That is a polypeptide?
Also, what is the difference between: protein domain, polypeptide, subunit.
I guess all the three words mean the same.

[canalon]

Protein domain: A portion of a protein usually defined by a specific function (zinc finger or some such). There might be more than one domain in one polypeptide.
Polypeptide: a large chain of amino acids, but not a protein.
Subunit: usually one of the many polypeptide composing a protein

[vinayaksabnis]

In case of protein with alcohol it will denature the side chains affecting hydrogen bondings while in case of protein with urea will affect covalent bonds and urea is a powerful denaturant than alcohol

[JackBean]

1) are you sure, that urea will disrupt covalent bonds? I highly doubt, since such denatured proteins can be renatured after dialysis.
2) how is that related to the topic?