|
Search over 100 encyclopedias and dictionaries: |
Research categories | Follow us on Twitter |
Research categories
View all topics in the newsView all reference sources at Encyclopedia.com |
|||
histidine
histidine , organic compound, one of the 22 α- amino acids commonly found in animal proteins. Only the l -stereoisomer appears in mammalian protein. Histidine is the direct precursor of histamine ; it is also an important source of carbon atoms in the synthesis of purines . The imidazole group on the side chain of histidine can act as both an acid and a base, i.e., it can both donate and accept protons under some conditions. This turns out to be an important property when histidine is incorporated into proteins , particularly when it becomes a part of the primary structure of some enzymes . It is thought that the side chain of this amino acid acts as a general acid and base as it participates in the catalytic functions of chymotrypsin , as well as those of a number of enzymes dealing with the metabolism of carbohydrates, proteins, and nucleic acids. It has even been implicated in the workings of cocoonase, the enzyme that allows adult silk moths to escape from their cocoons. Histidine is considered to be an essential amino acid for infants (it must be supplied in the diet); experiments with adults indicate that they can go for at least short periods without dietary intake of this amino acid. It was isolated from protein in 1896; its structure was confirmed by chemical synthesis in 1911. |
|
|
Cite this article
"histidine." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. 12 Feb. 2012 <http://www.encyclopedia.com>. "histidine." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. (February 12, 2012). http://www.encyclopedia.com/doc/1E1-histidin.html "histidine." The Columbia Encyclopedia, 6th ed.. 2008. Retrieved February 12, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-histidin.html |
|
histidine
histidine A basic, polar amino acid that contains an imidazole group (C3H4N2); it is the precursor of histamine.
|
|
|
Cite this article
MICHAEL ALLABY. "histidine." A Dictionary of Zoology. 1999. Encyclopedia.com. 12 Feb. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "histidine." A Dictionary of Zoology. 1999. Encyclopedia.com. (February 12, 2012). http://www.encyclopedia.com/doc/1O8-histidine.html MICHAEL ALLABY. "histidine." A Dictionary of Zoology. 1999. Retrieved February 12, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O8-histidine.html |
|
histidine
|
|
|
Cite this article
MICHAEL ALLABY. "histidine." A Dictionary of Plant Sciences. 1998. Encyclopedia.com. 12 Feb. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "histidine." A Dictionary of Plant Sciences. 1998. Encyclopedia.com. (February 12, 2012). http://www.encyclopedia.com/doc/1O7-histidine.html MICHAEL ALLABY. "histidine." A Dictionary of Plant Sciences. 1998. Retrieved February 12, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O7-histidine.html |
|
histidine
histidine (hist-i-deen) n. an amino acid from which histamine is derived.
|
|
|
Cite this article
"histidine." A Dictionary of Nursing. 2008. Encyclopedia.com. 12 Feb. 2012 <http://www.encyclopedia.com>. "histidine." A Dictionary of Nursing. 2008. Encyclopedia.com. (February 12, 2012). http://www.encyclopedia.com/doc/1O62-histidine.html "histidine." A Dictionary of Nursing. 2008. Retrieved February 12, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O62-histidine.html |
|
histidine
histidine An essential amino acid with a basic side chain.
|
|
|
Cite this article
DAVID A. BENDER. "histidine." A Dictionary of Food and Nutrition. 2005. Encyclopedia.com. 12 Feb. 2012 <http://www.encyclopedia.com>. DAVID A. BENDER. "histidine." A Dictionary of Food and Nutrition. 2005. Encyclopedia.com. (February 12, 2012). http://www.encyclopedia.com/doc/1O39-histidine.html DAVID A. BENDER. "histidine." A Dictionary of Food and Nutrition. 2005. Retrieved February 12, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O39-histidine.html |
|
histidine
histidine See amino acid.
|
|
|
Cite this article
"histidine." A Dictionary of Biology. 2004. Encyclopedia.com. 12 Feb. 2012 <http://www.encyclopedia.com>. "histidine." A Dictionary of Biology. 2004. Encyclopedia.com. (February 12, 2012). http://www.encyclopedia.com/doc/1O6-histidine.html "histidine." A Dictionary of Biology. 2004. Retrieved February 12, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O6-histidine.html |
|
Search over 100 encyclopedias and dictionaries:
HighBeam™ Research, Inc. © Copyright 2012. All rights reserved.
The Encyclopedia.com advertising network includes:
