hemoglobin allosteric

[TimeforDAT]

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Hemoglobin is an allosteric molecule. What does allosteric mean?

 

[Anemone]

Hemoglobin is an allosteric molecule. What does allosteric mean?

that the binding of one ligand ups the attraction of substrate to other binding sites. when o2 binds to one site on heme(it can hold 4 at a time), it causes its binding site to go through some conformational change that makes the other sites affinity for o2 go up.

 

[denttiger]

Well "allosteric" means it has more than one binding site and like Anemone said it does induce a conformational change upon binding.. but the actual increase in affinity for extra substrates upon binding is called "cooperativity". Just wanted to clarify on what Anemone said.

 

[dentistin2011]

yeh~
you need to distinguish the difference between 'allosteric' & 'cooperativity'

 

[Dotoday]

Allostery means that a protein has more than one binding site for the substrate(s). Yes hemoglobin is an allosteric molecule because it has 4 binding sites for the Oxygen. Hemoglobin can bind 4 oxygen molecules. Yes cooperativity is different, cooperativity, again in Hemoglobin is when one ligand enhances the binding of the other ligand. Of course in order for the molecule to exhibit cooperative binding, it therefore must be allosteric.
I hope the answers your question.