Talk:Peptide bond

Nomenclature change?

Suggestion: Change the title and all references to peptide bond to peptide linkage. —Preceding unsigned comment added by 134.226.1.229 (talk • contribs) 09:25, 23 October 2006 9UTC)

Umm, why do you think that "peptide linkage" is more common than "peptide bond"? The latter seems to be the international standard, no? Willow 11:33, 23 October 2006 (UTC)

I agree with keeping the current title. Keep the name 'peptide bond'. This is what students will look for when trying to find additional information. 74.192.206.176 22:04, 22 March 2007 (UTC)

Yes but it doesn't seem to actually say that amide bond = peptide bond.--129.67.177.165 (talk) 18:11, 4 November 2010 (UTC)

more general informaton

... — Preceding unsigned comment added by 194.150.177.10 (talk) 18:45, 28 February 2012 (UTC)

This article seems to take a lot of things for granted, like the readers undertsanding of the material. Also there is no mention of who discovered peptide bonds, or named them.What does peptide mean? this might be useful. —The preceding unsigned comment was added by 72.149.155.83 (talk) 19:57, 12 May 2007 (UTC).

Figure 1: Error?

In figure 1 there seems to be an inconsistency. As far as I remember from high school chemistry, in a reaction there should be the same number of elements on both sides. On the left of the equation there is no carbon element but on the right there suddenly is. I suspect that the oxygen element with the double bond should have been a carbon element. can someone more knowledgable take a look at this matter and take appropriate actions please. —Preceding unsigned comment added by Kubi KZ (talk • contribs) 18:46, August 27, 2007 (UTC)

Figure 1 is perfectly ok. Chemists tend to use short-cut formulae like that on the right, where each corner where lines meet that is not labeled with an atom symbol means a carbon atom.

What troubles me much more is Figure 3!!!! There is no such thing as a nitrogen carrying FIVE bonds. Four bonds is the absolute maximum, even in biochemistry. Also, the electron lone pair of the nitrogen atom is involved heavily in the amide resonance. Consequently, it is not easy to either be protonated or accept a hydrogen bond. The hydrogen bond acceptor in an amide bond is the carbonyl oxygen atom. In the chemical literature, there exist a few reports that the nitrogen gets protonated, but this seems to be very rare. If one protonates the carbonyl oxygen instead, one creates a resonance-stabilized cation. Consequently, the oxygen is the basic site!!

Figure 3 is therefore completely wrong and should definitively be removed or replaced by some other figure! —Preceding unsigned comment added by 160.45.22.226 (talk) 13:37, 24 January 2008 (UTC)

The hydrogen bond was shown with horizontal dashes, which was a bit confusing since those are often used in stereochemical drawings. I replaced this with a dotted line. Tim Vickers (talk) 03:13, 25 January 2008 (UTC)

In figure 3, the nitrogen should only have a single bond with the unlabeled carbon. See Ferst Alan, Structure and Mechanism in Protein Science ISBN 0-7167-3268-8 figure 1.3 on page 10.

Hi there. Isn't that only true in one of the resonance structures? If you ignore the hydrogen bond (dotted line) the nitrogen has three bonds in the left-hand panel and four in the right-hand panel. Which panel are you referring to? Tim Vickers (talk) 17:57, 23 December 2008 (UTC)

They are all fine —Preceding unsigned comment added by What do i want to... (talk • contribs) 13:16, 26 November 2009 (UTC)

I think that figure 1 is wrong because those molecules would undergo acid base chemistry over Nucleophilic Acyl Substitution. Correct me if I'm wrong. —Preceding unsigned comment added by 128.189.208.85 (talk) 01:30, 11 December 2010 (UTC)

Cleanup

....as nylons and aramids, are synthetic molecules (polymers) with peptide bonds.... That is utterly errant. The peptide bond is a concept used in context of amino acids, extended with ramachandran plots etc, etc. Seems to have been penned by a molbioist. Irregardlesss, the article ought to be improved.Slicky (talk) 09:44, 8 February 2008 (UTC) "By contrast, donating a hydrogen bond to an amide nitrogen in an X-Pro peptide bond should favor the single-bonded form; donating it to the double-bonded form would give the nitrogen five quasi-covalent bonds! (See Figure 3.)" BSSlicky (talk) 09:58, 8 February 2008 (UTC)

Covalent vs. non-covalent?

This page refers to peptide bonds as noncovalent, but my biochem, organic chem, and molecular biology textbooks all refer to peptide bonds as covalent bonds. Is this an error or has new research come to light to show that these bonds do not involve sharing electrons? --Amphisbaenia (talk) 16:02, 8 February 2009 (UTC)

That was vandalism, removed. --Rifleman 82 (talk) 16:28, 8 February 2009 (UTC)

Run-on sentence

The first sentence in this article is a run-on sentence. — Preceding unsigned comment added by First down comets (talk • contribs) 06:14, 17 January 2012 (UTC)

SI Units

I have added in the relevant SI units - we really ought to have those throughout all such articles. I have NOT removed the kcals but rather put them in brackets. All conversions are approximate - ie multiplying by 4 rather than 4.18 — Preceding unsigned comment added by 86.140.109.247 (talk) 15:11, 13 February 2012 (UTC)

History

Could someone add history to the main page? Such as when the peptide bond was discovered and who discovered it? Reason I note this down is because I have an entry here 1902 discovered by Emil Fischer, but when I went to the Emil Fischer wikipedia page, it made no such mention and the page here also does not mention when it was discovered and by whom, so it would be nice if this information could be added. 2A02:8388:1641:4700:BE5F:F4FF:FECD:7CB2 (talk) 03:15, 15 January 2017 (UTC)

DEFINITION needs to be changed

`A peptide bond (amide bond) is a covalent chemical bond linking two consecutive amino acid monomers along a peptide or protein chain.`

Though this definition is highly cited, but there are exceptions where peptide bonds exist outside polypeptides, between an amino acid/amino-acid derivative and an non-amino acid molecule. e.g.

Glycocholic acid is a conjugated bile acid that is formed by a peptide linkage between Glycine and cholic acid (cholylCoA).

Taurocholic acid another conjugated bile acid that is formed by a peptide linkage between Taurine, an amino sulfonic acid and cholic acid (cholylCoA).

Sources: 1 and 2

Looks like the article once had this information which is know removed. I think it will be good to also have it protected from edits.

--Sanjukta1995 (talk) 11:25, 4 May 2017 (UTC)