I am trying to understand the distance requirement for hydrogen bonding to occur (more specifically in the context of protein folding). There needs to be a donor and acceptor atom for bonding to occur. What is the range of distances between these atoms where one can say that a hydrogen bonding is likely to occur when the polypeptide is in an aqueous environment? Is it element pair specific?
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2$\begingroup$ Yes. there is element and orientation dependence. There is no simple answer to this, lengthy papers and even lengthier discussions are being had over this issue. $\endgroup$– TAR86Commented May 14, 2020 at 19:29
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You will probably find all this information in biochemistry textbook. To give you an idea in proteins, typically; alpha helices H..O distance is 2.06 Angstrom, and N..O, 2.99. In beta sheets (parallel) H--O 1.97, N--O 2.29 and in anti parallel sheets, H--O 1.96 and N--OI 2.91. These H bonds are not linear, e.g C=O..H-N typically 150 to 160 degree for COH or NHO angle.
In Watson-Crick base pairing in DNA, (C-G pairs) the linear H-bond distances are $\mathrm{N_4-(H)-O_6}$ 2.91, $\mathrm{N_3-(H)-N_1}$ 2.95, and $\mathrm{O_2-(H)-N_2}$ 2.86.
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$\begingroup$ Can you point me to a specific textbook or website where I can get this information? I am looking for some rough rules of thumb in the form of: If the distance is below a certain threshold and the other conditions are met, the two atoms could form a hydrogen bond. $\endgroup$– ChrisCommented May 15, 2020 at 15:13
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$\begingroup$ I found this link right after the answer was posted. bio.brandeis.edu/classes/biochem104/hydrogen_bonds.pdf $\endgroup$– ChrisCommented May 15, 2020 at 15:17
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1$\begingroup$ @Chris Here is another source, citing a book by Jeffrey on hydrogen bonds: proteopedia.org/wiki/index.php/… $\endgroup$– Karsten ♦Commented May 19, 2020 at 14:17