1TIH

TRYPSIN INHIBITOR (T1) FROM NICOTIANA ALATA

1TIH の概要

• エントリーDOI: 10.2210/pdb1tih/pdb
• 分子名称: TRYPSIN INHIBITOR T1 (1 entity in total)
• 機能のキーワード: serine proteinase inhibitor, potato ii trypsin inhibitor, nicotiana alata trypsin inhibitor, proteinase inhibitor (trypsin)
• 由来する生物種: Nicotiana alata (Persian tobacco)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 5740.51

構造登録者

Nielsen, K.J.,Heath, R.L.,Anderson, M.A.,Craik, D.J. (登録日: 1995-08-03, 公開日: 1995-10-15, 最終更新日: 2024-10-30)

主引用文献

Nielsen, K.J.,Heath, R.L.,Anderson, M.A.,Craik, D.J.
Structures of a series of 6-kDa trypsin inhibitors isolated from the stigma of Nicotiana alata.
Biochemistry, 34:14304-14311, 1995

PubMed Abstract: 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.

PubMed: 7578034
DOI: 10.1021/bi00044a007

実験手法

SOLUTION NMR