1tih
From Proteopedia
(New page: 200px<br /><applet load="1tih" size="450" color="white" frame="true" align="right" spinBox="true" caption="1tih" /> '''TRYPSIN INHIBITOR (T1) FROM NICOTIANA ALATA'...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1tih.jpg|left|200px]]<br /><applet load="1tih" size=" | + | [[Image:1tih.jpg|left|200px]]<br /><applet load="1tih" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1tih" /> | caption="1tih" /> | ||
'''TRYPSIN INHIBITOR (T1) FROM NICOTIANA ALATA'''<br /> | '''TRYPSIN INHIBITOR (T1) FROM NICOTIANA ALATA'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The three-dimensional structures of a series of 6-kDa trypsin inhibitors | + | The three-dimensional structures of a series of 6-kDa trypsin inhibitors isolated from the stigma of the ornamental tobacco Nicotiana alata have been determined by 1H NMR spectroscopy combined with simulated annealing calculations. The proteins, T1-T4, are proteolytically cleaved from a 40.3-kDa precursor protein, NA-proPI, together with a chymotrypsin inhibitor, C1, the structure of which was reported recently [Nielsen, K.J., Heath, R.L., Anderson, M.A., & Craik, D.J. (1994) J. Mol. Biol. 242, 231-243]. Each of the proteinase inhibitors comprises 53 amino acids, including 8 cysteine residues which are linked to form 4 disulfide bridges. The proteins have a high degree of sequence identity and differ mainly in residues around the putative reactive sites. The structure of T1 was determined using a set of 533 interproton distance restraints derived from NOESY spectra, combined with 33 dihedral restraints derived from 3JNH-H alpha coupling constants and 16 hydrogen bonds. The structures of the remaining inhibitors (T2-T4) were deduced to be almost identical to T1, on the basis of their similar chemical shifts and 2D spectra. The current study demonstrates that the structures of the trypsin inhibitors (T1-T4) are similar to that previously found for the chymotrypsin inhibitor, C1. Despite differences in sequence, there is conservation in backbone geometry between the reactive site loops of the two classes of inhibitors. From this, it is clear that the nature of the side chain on the primary binding residue, rather than the backbone fold, is the main determinant of the enzyme specificities of these proteinase inhibitors. |
==About this Structure== | ==About this Structure== | ||
| - | 1TIH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Nicotiana_alata Nicotiana alata]. Full crystallographic information is available from [http:// | + | 1TIH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Nicotiana_alata Nicotiana alata]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TIH OCA]. |
==Reference== | ==Reference== | ||
| Line 13: | Line 13: | ||
[[Category: Nicotiana alata]] | [[Category: Nicotiana alata]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Anderson, M | + | [[Category: Anderson, M A.]] |
| - | [[Category: Craik, D | + | [[Category: Craik, D J.]] |
| - | [[Category: Heath, R | + | [[Category: Heath, R L.]] |
| - | [[Category: Nielsen, K | + | [[Category: Nielsen, K J.]] |
[[Category: nicotiana alata trypsin inhibitor]] | [[Category: nicotiana alata trypsin inhibitor]] | ||
[[Category: potato ii trypsin inhibitor]] | [[Category: potato ii trypsin inhibitor]] | ||
[[Category: serine proteinase inhibitor]] | [[Category: serine proteinase inhibitor]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:14:00 2008'' |
Revision as of 13:14, 21 February 2008
|
TRYPSIN INHIBITOR (T1) FROM NICOTIANA ALATA
Overview
The three-dimensional structures of a series of 6-kDa trypsin inhibitors isolated from the stigma of the ornamental tobacco Nicotiana alata have been determined by 1H NMR spectroscopy combined with simulated annealing calculations. The proteins, T1-T4, are proteolytically cleaved from a 40.3-kDa precursor protein, NA-proPI, together with a chymotrypsin inhibitor, C1, the structure of which was reported recently [Nielsen, K.J., Heath, R.L., Anderson, M.A., & Craik, D.J. (1994) J. Mol. Biol. 242, 231-243]. Each of the proteinase inhibitors comprises 53 amino acids, including 8 cysteine residues which are linked to form 4 disulfide bridges. The proteins have a high degree of sequence identity and differ mainly in residues around the putative reactive sites. The structure of T1 was determined using a set of 533 interproton distance restraints derived from NOESY spectra, combined with 33 dihedral restraints derived from 3JNH-H alpha coupling constants and 16 hydrogen bonds. The structures of the remaining inhibitors (T2-T4) were deduced to be almost identical to T1, on the basis of their similar chemical shifts and 2D spectra. The current study demonstrates that the structures of the trypsin inhibitors (T1-T4) are similar to that previously found for the chymotrypsin inhibitor, C1. Despite differences in sequence, there is conservation in backbone geometry between the reactive site loops of the two classes of inhibitors. From this, it is clear that the nature of the side chain on the primary binding residue, rather than the backbone fold, is the main determinant of the enzyme specificities of these proteinase inhibitors.
About this Structure
1TIH is a Single protein structure of sequence from Nicotiana alata. Full crystallographic information is available from OCA.
Reference
Structures of a series of 6-kDa trypsin inhibitors isolated from the stigma of Nicotiana alata., Nielsen KJ, Heath RL, Anderson MA, Craik DJ, Biochemistry. 1995 Nov 7;34(44):14304-11. PMID:7578034
Page seeded by OCA on Thu Feb 21 15:14:00 2008
