Talk:Protein structure

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The original text for this article was taken from: http://www-structure.llnl.gov/Xray/tutorial/protein_structure.htm and claimed as "public domain". However on the Disclaimer linked from this page: http://www.llnl.gov/disclaimer.html it says:

Copyright Status

LLNL-authored documents are sponsored by the U.S. Department of Energy under Contract W-7405-Eng-48. Accordingly, the U.S. Government retains a nonexclusive, royalty-free license to publish or reproduce these documents, or allow others to do so, for U.S. Government purposes. All documents available from this server may be protected under the U.S. and Foreign Copyright Laws. Permission to reproduce may be required.

It thus not clear that these pages can be used under public domain provisions, although the DOE (which funds LLNL) being a US govt. agency should, in theory, be covered under the blanket no-copyright rule for all federal US agencies. It concerns me that they have the statement: "or allow [...] for U.S. Government purposes". Perhaps they are more worried about the copyright status of text they didn't author. If a copyright-wonk could clarify this for us, it would be useful. Thanks. --Lexor|Talk 02:24, Oct 8, 2004 (UTC)

Too much amino acid content?

It seems like there is way too much detailed and redundant information about amino acids in this topic. This topic should focus on generic aspects of protein structure. There is already ample description of amino acid chemistry in the amino acid article. Anyone else have thoughts on this? Speedyboy 21:19, 31 January 2007 (UTC)[reply]

Dominant forces in 2° and 3° structure?

Hi, just a word about the recent edit specifying the molecular forces stabilizing different types of protein structure. Protein 2° structure is certainly defined by its hydrogen bonds, but it might be a little misleading to say that it is stabilized by its hydrogen bonds; if that were true, then peptides taken from a protein would adopt stable 2° structure, which is extremely rare. The reason is that water-amide hydrogen bonds are generally more favorable than amide-amide hydrogen bonds; that's why the 2° structure disintegrates when the 3° structure of a protein is unfolded by tension, pressure or cold denaturation.

Likewise, disulfide bonds are extremely rare in cytosolic proteins, since the cytosol is a reducing environment thanks to the high concentration of glutathione. With a few exceptions in thermophiles, disulfide bonds are found only in extracellular proteins such as secreted toxins, inhibitors, digestive enzymes, etc. So I hope you won't mind the changes I'm about to make in the edit; thanks for being understanding! :) Willow 17:35, 5 February 2007 (UTC)[reply]

Additional structural motives

I'm hardly searching for an explanation for the term beta-jelly-roll motive. Some help would be great!

Thx Monsterous mad max 14:23, 16 August 2007 (UTC)[reply]

Alpha Amino Acid picture

Could this be replaced with this one without losing information: http://upload.wikimedia.org/wikipedia/commons/c/ce/AminoAcidball.svg ?