View source for 1qif

[[Image:1qif.jpg|left|200px]]<br /><applet load="1qif" size="350" color="white" frame="true" align="right" spinBox="true" 
caption="1qif, resolution 2.10&Aring;" />
'''SPECIFIC CHEMICAL AND STRUCTURAL DAMAGE AT NINE TIME POINTS (POINT C) CAUSED BY INTENSE SYNCHROTRON RADIATION TO TORPEDO CALIFORNICA ACETYLCHOLINESTERASE'''<br />

==Overview==
Radiation damage is an inherent problem in x-ray crystallography. It usually is presumed to be nonspecific and manifested as a gradual decay in the overall quality of data obtained for a given crystal as data collection proceeds. Based on third-generation synchrotron x-ray data, collected at cryogenic temperatures, we show for the enzymes Torpedo californica acetylcholinesterase and hen egg white lysozyme that synchrotron radiation also can cause highly specific damage. Disulfide bridges break, and carboxyl groups of acidic residues lose their definition. Highly exposed carboxyls, and those in the active site of both enzymes, appear particularly susceptible. The catalytic triad residue, His-440, in acetylcholinesterase, also appears to be much more sensitive to radiation damage than other histidine residues. Our findings have direct practical implications for routine x-ray data collection at high-energy synchrotron sources. Furthermore, they provide a direct approach for studying the radiation chemistry of proteins and nucleic acids at a detailed, structural level and also may yield information concerning putative "weak links" in a given biological macromolecule, which may be of structural and functional significance.

==About this Structure==
1QIF is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Torpedo_californica Torpedo californica]. Active as [http://en.wikipedia.org/wiki/Acetylcholinesterase Acetylcholinesterase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.1.7 3.1.1.7] Known structural/functional Site: <scene name='pdbsite=CAT:Catalytic+Triad'>CAT</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QIF OCA]. 

==Reference==
Specific chemical and structural damage to proteins produced by synchrotron radiation., Weik M, Ravelli RB, Kryger G, McSweeney S, Raves ML, Harel M, Gros P, Silman I, Kroon J, Sussman JL, Proc Natl Acad Sci U S A. 2000 Jan 18;97(2):623-8. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=10639129 10639129]
[[Category: Acetylcholinesterase]]
[[Category: Single protein]]
[[Category: Torpedo californica]]
[[Category: Kryger, G.]]
[[Category: Ravelli, R B.G.]]
[[Category: Weik, M.]]
[[Category: alpha/beta hydrolase]]
[[Category: catalytic triad]]
[[Category: disulfide bond]]
[[Category: glycosylated protein]]
[[Category: neurotransmitter cleavage]]
[[Category: radiation damage]]
[[Category: serine hydrolase]]
[[Category: time series]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:39:57 2008''