Stability of protein back bone? - (Aug/24/2007 )

hi

How stable is protein back bone?? How stable are these bonds compared to other bondings in a protein??

Also can presences of certain amino acids makes the peptide bonds weaker??

-rick112-

QUOTE (rick112 @ Aug 24 2007, 06:33 PM)

hi

How stable is protein back bone?? How stable are these bonds compared to other bondings in a protein??

Also can presences of certain amino acids makes the peptide bonds weaker??

By 'other bondings' do you mean the hydrogen bonds, disulphide bonds, hydrophobic interactions etc that go to make up the secondary and tertiary structure? All but the disulphide are non-covalent interactions, so they are inherently unstable, and can be broken by heat, pH, salt etc.
The backbone is quite stable, and requires enzymes or extremes of pH to break.

-swanny-

yes, by other bonds i have mean mean the hydrogen bonds, disulphide bonds, hydrophobic interactions etc also disulphide interactions....
i was intersed if can prescence of some amino acids make protein back bone weak,...??

-rick112-

QUOTE (rick112 @ Aug 24 2007, 08:33 AM)

hi

How stable is protein back bone?? How stable are these bonds compared to other bondings in a protein??

Also can presences of certain amino acids makes the peptide bonds weaker??

Hi... I dont know how the stable protein backbons are, but I know that compatible solutes like ectoin make it more stable, simply becouase it support the protein backbones by substitution of water with ectoine wich are low molecular wieght molecules highly present in halophilic bacteria.

-hemin-

Peptidase/protease and some very harsh chemical reactions can break off the amide bonds. These are more or less aa sequence dependent. Oxidation and reduction reactions break off S-S linkages. Hydrophobic residues contribute to the hydrophobic interactions. Salt, pH, urea and high concentration of many other substance can affect hydrogen bonding.

I dont know if I've answered your questions.

-genehunter-1-

hi every one,
thanks for ur reply..
well little history regarding the question, one of my friend while discussing told that presence of certain protein make the protein inherently weak..i was noty that convinced, so thought will put up here...
so what you all think..do you all support this claim or..???if you support please provide its relevant reasons plz

-rick112-

QUOTE (rick112 @ Aug 30 2007, 09:05 PM)

Your friend sounds like they might be spinning you a story. Find out what protein does this. Tell them you need some actual data, not just someone's third- or fourth-hand statements (have you heard of the children's game 'Chinese whispers'?)

-swanny-