Talk:Peptide

message: Q: What is the difference between a peptide and a protein? :S Brutulf 16:34, Apr 4, 2005 (UTC)
A: Peptides are less than 50 amino acids long and they do not have secondary and tertiary structures. Therefore they can fold into a variety of shapes. e.g. Insulin.
Proteins, however, have more than 50 amino acids. They have secondary and tertiary structures, and therefore most proteins have fixed shapes. e.g. Hemoglobin.
* See Also:  Grand Peptide List The Biochemical Basis of Neuropharmacology Oxford Press 1996--McDogm 16:42, 6 May 2005 (UTC)
replies: text: Re: "are less than 50 amino acids long and they do not have secondary and tertiary structures. Therefore they can fold into a variety of shapes. e.g. Insulin." - I'm afraid I have to disagree with that! Insulin most definitely has a well defined secondary and tertiary structure! I(q) = User(q)·Talk(q) 15:08, 3 September 2011 (UTC)

text: Nevertheless there a huge differences even between proteins. And without any doubt complex "peptides" like insulin are in fact proteins, they just wear the wrong name. IMHO all peptides with secondary and tertiary structures are proteins. "It' the structure, s.....". --178.197.229.5 (talk) 00:40, 17 January 2014 (UTC)
replies: text: I don't think we should have to come to the talk page to find out if proteins qualify as peptides. There should be at least a sentence in the article making clear that chains of over approximately 50 residues aren't allowed to call themselves peptides. 2602:306:BC65:4069:1511:E4C9:2E9E:4950 (talk) 20:37, 5 June 2022 (UTC)
thread_title:  Peptides vs. Proteins: 

message: I can't find any reliable references about dermorphin, casomorphin or gluten exorphin contributing to mental illness in PubMed. Tim Vickers 03:21, 17 October 2007 (UTC)
thread_title: This section needs references

message: "Isobaric peptides" rederects here, but there isn't any information on that page, not even the word itself...
I'm currently finishing my thesis, but if someone has the time... Kosmologie (talk) 14:30, 15 September 2009 (UTC)
thread_title: Isobaric peptides

message: Any chance someone whose Greek is a bit sounder than mine could check the translation (in the introduction) 
        Greek πεπτίδια, "small digestibles"
?  I don't think the 'small' idea appears within the meaning of πεπτίδια.  That is, I think πεπτίδια means "digestibles" rather than "small digestibles".  I'm not even sure about "digestibles" (I think it may mean "things that have been digested": "digestion products"), but it's 'small' that matters - because of the confusion / controversy about peptides / polypeptides / proteins.  Some people (see posts above) consider that the size of the molecule is the point here (eg 50+ is a polypeptide or protein), some the structure (ie secondary/tertiary means protein, primary-only means peptide) - and of course the other 99+% of readers aren't specialists, have no opinion and are hoping it's our role to inform them.  
Of this non-specialist majority, many are 'victims' turning to us for rescue from drowning in 'cosmeceutical' guff.
On the specialist side of the fence, I gather small polypeptides like cytokines are an emerging and increasingly autonomous area of study.  (There's an interesting long post on the talk-page for Cytokines, about a claimed almost regulatory role in the mind/body relationship under conditions of immune-challenge.  It argues that the fairly new-drafted article is behind the times.)  Within this new field, I suspect some partisans view typically larger molecules like hormones as unfashionable subjects ("so last-century, dahling"?).  (Where passions run high, NPOV Wikipronouncements will have special value.)
I'm kinda guessing, though, about this.  Can anyone with direct experience of the research community/ies comment? edit boldly?
As a simple opening move, can someone more confident of their Greek sharpen up the πεπτίδια thing?
SquisherDa (talk) 06:59, 25 June 2010 (UTC)
thread_title: "small digestibles" / πεπτίδια

message: Isn't it a bit overkill to have figures of *two* dipeptides *and* one tetrapeptide? The figure of the tetrapeptide should be sufficient. Carstensen (talk) 11:37, 20 October 2011 (UTC)
replies: text: I'd agree, it also doesn't help that the Gly-Ala dipeptide image is looking a bit dated.   (+)H3N-Protein\Chemist-CO2(-) 14:15, 21 October 2011 (UTC)
thread_title: Figures

message: In the article about peptides, there is nothing about it.
http://en.wikipedia.org/wiki/Copper_peptide_GHK-Cu
Why?  — Preceding unsigned comment added by Kenorb (talk • contribs) 09:43, 13 February 2012 (UTC)
thread_title:  What about copper peptides? 

message: Peptides are in the news this week in Australia in relation to some kind of illegal use in sports. Does someone with any knowledge of those stories, and/or the possible benefits of peptides want to add a new section to the article? I cam here to find out why they might be useful or banned but didn't see anything relevant.  — Preceding unsigned comment added by 124.149.169.161 (talk) 11:18, 11 February 2013 (UTC)
thread_title:  Peptides and their (illegal?) use in sports. 

message: Every advert at the moment claims that pentapeptides can make their produce "reduce the signs of aging"... I came to this article to find out if this was true, but no luck. Possibly a section needed to address this as this term has become a household term recently.  —Preceding unsigned comment added by Giant toaster (talk • contribs) 07:44, 29 June 2008 (UTC)
replies: text: Doesn't seem either probable or important to me. Tim Vickers (talk) 15:50, 29 June 2008 (UTC)

text: Attributing some property to a peptide on the grounds that it is a pentapeptide (ie, consists of 5 amino acids) is like saying a molecule with 5 carbon atoms will have a specific property; ie nonsensical.  —Preceding unsigned comment added by 121.79.24.62 (talk) 02:42, 8 August 2008 (UTC)
replies: text: This is true, but the fact is that Olay - at least in the UK - is making such claims relating to pentapeptides. As Giant Toaster says, the term has become far more widely known as a result. Nick Cooper (talk) 07:51, 16 August 2008 (UTC)

text: The new section seems skechy. I removed the obvious advertising, but the whole section should be removed in my opinion. CombatWombat42 (talk) 18:30, 24 January 2014 (UTC)

text: I understand your point about the last paragraph and it is true that it concerns only one peptide among millions of them, so it should be removed. But I don't understand why you removed the whole section, it is properly documented (valid scientific reference) and as you mentioned at the beginning of this section, peptides are more and more mentioned in the cosmetic industry and it is important to explain in an article dealing with peptides why and how they are used for these specific applications. The researches made for medical applications are often used in cosmetics as the skin is a major organ of the human body.Pcriton (talk) 12:45, 28 January 2014 (UTC)
replies: text: I have moved the material by  to a draft where you can work on it further (with assistance from other Wikipedians): Draft:Peptides in skin care. --Hroðulf (or Hrothulf) (Talk) 13:54, 28 January 2014 (UTC)
replies: text: Thanks for the move, Hroðulf. My concerns about the section echo 121.79.24.62 and Hroðulf, one peptide possibly being usefull in one situation dosn't sem WP:NOTABLE and the section seemed a lot like advertising. CombatWombat42 (talk) 15:56, 28 January 2014 (UTC)
thread_title:  Beauty products? 

message: Adjectives are generally not suitable article titles. Best merged to Peptide with minimal definition. No need for superfluous stubs. --Animalparty-- (talk) 20:04, 21 October 2014 (UTC)
thread_title:  Proposed merge with [[Peptidergic]] 

message: Substituted at 02:37, 30 April 2016 (UTC)
thread_title: Assessment comment

message: The section entitled "Peptide classes" begins with the (unreferencced) statement, which I dispute:
"Peptides are divided into several classes, depending on how they are produced:
*Milk peptides Two naturally occurring milk peptides...
*Ribosomal peptides are synthesized by translation of mRNA...
*Nonribosomal peptides are assembled by enzymes ... glutathione.
*Peptones are derived from animal milk or meat digested by proteolysis....
*Peptide fragments refer to fragments of proteins that are used to identify or quantify the source protein.."
Maybe a dairy person got a hold of this article, but the idea of near equivalency of ribosomal peptides vs "milk peptides" seems to be WP:UNDUE.  My guess is that there are
*ribosomal peptides
*the rest (degradation products, glutathione, odd and ends).
It would be helpful if a biochemical expert looked over this section.  --Smokefoot (talk) 23:49, 3 September 2018 (UTC)
replies: text: I agree with this. It seems to a pretty random assortment. Probably ribosomal, protine-derived, and non-ribosomally synthesised. I've emailed a few peptide researchers from different specialisations to get some opinions of how to update the page. T.Shafee(Evo&Evo)talk 11:17, 7 September 2018 (UTC)
thread_title: Dispute: Peptide classes

message: I always thought that albumins are complexes of several proteins  — Preceding unsigned comment added by 86.38.242.213 (talk) 18:44, 27 February 2020 (UTC)
thread_title:  where do you mention albumins? 

message: peptide bioregulator or  bioregulator peptide --What is this?  It is being hyped as an anti-aging item. If this is more than just a scam or fringe idea, the article should discuss this.  In fact, the Wikipedia article on one of them, epitalon, seems to say that it is a legitimate research concern. 2600:6C67:1C00:5F7E:2C52:C3AF:FEAF:5B1F (talk) 14:09, 8 October 2022 (UTC)
thread_title:  peptide bioregulator