2f9o: Difference between revisions
From Proteopedia
Jump to navigationJump to search
New page: left|200px<br /> <applet load="2f9o" size="450" color="white" frame="true" align="right" spinBox="true" caption="2f9o, resolution 2.10Å" /> '''Crystal Structure o... |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:2f9o.gif|left|200px]]<br /> | [[Image:2f9o.gif|left|200px]]<br /><applet load="2f9o" size="350" color="white" frame="true" align="right" spinBox="true" | ||
<applet load="2f9o" size=" | |||
caption="2f9o, resolution 2.10Å" /> | caption="2f9o, resolution 2.10Å" /> | ||
'''Crystal Structure of the Recombinant Human Alpha I Tryptase Mutant D216G'''<br /> | '''Crystal Structure of the Recombinant Human Alpha I Tryptase Mutant D216G'''<br /> | ||
==Overview== | ==Overview== | ||
Tryptases alpha and beta are trypsin-like serine proteinases expressed in | Tryptases alpha and beta are trypsin-like serine proteinases expressed in large amounts by mast cells. Beta-tryptase is a tetramer that has enzymatic activity, but requires heparin binding to maintain functional and structural stability, whereas alpha-tryptase has little, if any, enzymatic activity but is a stable tetramer in the absence of heparin. As shown previously, these differences can be mainly attributed to the different conformations of the 214-220 segment. Interestingly, the replacement of Asp216 by Gly, which is present in beta-tryptase, results in enzymatically active but less stable alpha-tryptase mutants. We have solved the crystal structures of both the single (D216G) and the double (K192Q/D216G) mutant forms of recombinant human alphaI-tryptase in complex with the peptide inhibitor leupeptin, as well as the structure of the non-inhibited single mutant. The inhibited mutants exhibited an open functional substrate binding site, while in the absence of an inhibitor, the open (beta-tryptase-like) and the closed (alpha-tryptase-like) conformations were present simultaneously. This shows that both forms are in a two-state equilibrium, which is influenced by the residues in the vicinity of the active site and by inhibitor/substrate binding. Novel insights regarding the observed stability differences as well as a potential proteolytic activity of wild-type alpha-tryptase, which may possess a cryptic active site, are discussed. | ||
==About this Structure== | ==About this Structure== | ||
2F9O is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Active as [http://en.wikipedia.org/wiki/Tryptase Tryptase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.59 3.4.21.59] Full crystallographic information is available from [http:// | 2F9O is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Active as [http://en.wikipedia.org/wiki/Tryptase Tryptase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.59 3.4.21.59] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2F9O OCA]. | ||
==Reference== | ==Reference== | ||
| Line 18: | Line 17: | ||
[[Category: Huber, R.]] | [[Category: Huber, R.]] | ||
[[Category: Marquardt, U.]] | [[Category: Marquardt, U.]] | ||
[[Category: Rohr, K | [[Category: Rohr, K B.]] | ||
[[Category: Schechter, N | [[Category: Schechter, N M.]] | ||
[[Category: Selwood, T.]] | [[Category: Selwood, T.]] | ||
[[Category: Than, M | [[Category: Than, M E.]] | ||
[[Category: difucosylation]] | [[Category: difucosylation]] | ||
[[Category: serine proteinase]] | [[Category: serine proteinase]] | ||
[[Category: trypsin-like]] | [[Category: trypsin-like]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:19:10 2008'' | ||
