beta pleated sheets and H-bonding

[andyjl]

on Kaplan explanation of beta pleated sheets on p. 481 it says
"in beta pleated sheets, peptide chains lie alongside each other in rows. the chains are held together by INTRAmolecular hydrogen bonds between carbonyl oxygen atoms on peptide chain and amine hydrogen atoms on another."

in an answer explanation for #10 for the quiz, it says that "INTERmolecular hydrogen bonds are characteristic of beta pleated sheets."

is it intra or intermolecular h-bonding?

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[DMDreaming]

on Kaplan explanation of beta pleated sheets on p. 481 it says
"in beta pleated sheets, peptide chains lie alongside each other in rows. the chains are held together by INTRAmolecular hydrogen bonds between carbonyl oxygen atoms on peptide chain and amine hydrogen atoms on another."

in an answer explanation for #10 for the quiz, it says that "INTERmolecular hydrogen bonds are characteristic of beta pleated sheets."

is it intra or intermolecular h-bonding?

Intermolecular according to my Biochem book.

 

[andyjl]

are the beta sheets for the secondary protein structure run anti-parallel to each other?

and the alpha helix is just a coiled structure right?

 

[DentalKitty]

on Kaplan explanation of beta pleated sheets on p. 481 it says
"in beta pleated sheets, peptide chains lie alongside each other in rows. the chains are held together by INTRAmolecular hydrogen bonds between carbonyl oxygen atoms on peptide chain and amine hydrogen atoms on another."

in an answer explanation for #10 for the quiz, it says that "INTERmolecular hydrogen bonds are characteristic of beta pleated sheets."

is it intra or intermolecular h-bonding?

I remember noticing that discrepancy as well. From what I understand, each B-strand is considered a peptide, and they are usually pretty far apart primary sequence wise, so bonding between them is considered intermolecular despite being part of the same overall protein molecule. It seems confusing though. A-helices H-bond i to i+4 so they are considered intramolecular because the bonds are so close together in the primary sequence. HTH

 

[xdianaax]

are the beta sheets for the secondary protein structure run anti-parallel to each other?

and the alpha helix is just a coiled structure right?

The alpha helix is a coiled structure, and the best way to describe beta sheet is one of those paper fans you used to make as a kid, kind of staircase looking, hope that helps!

 

[andyjl]

The alpha helix is a coiled structure, and the best way to describe beta sheet is one of those paper fans you used to make as a kid, kind of staircase looking, hope that helps!

i'm wondering if the beta sheets are considered anti-parallel or parallel, i remember something like that from bio class years ago. Not sure which one it is, i think it is anti-parallel?

 

[Lonely Sol]

i'm wondering if the beta sheets are considered anti-parallel or parallel, i remember something like that from bio class years ago. Not sure which one it is, i think it is anti-parallel?

Yea, B-pleated sheet usually run anti-parallel to each other since it makes it more stable. However, there are some that run paralle, which causes kinks in the bonds it makes. Its not stable