Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Submitted: 

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Solution structure and backbone dynamics of recombinant Cucurbita maxima trypsin inhibitor-V determined by NMR spectroscopy.

Liu, J.Prakash, O.Cai, M.Gong, Y.Huang, Y.Wen, L.Wen, J.J.Huang, J.K.Krishnamoorthi, R.

(1996) Biochemistry 35: 1516-1524

  • DOI: 10.1021/bi952466d
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The solution structure of recombinant Cucurbita maxima trypsin inhibitor-V (rCMTI-V), whose N-terminal is unacetylated and carries an extra glycine residue, was determined by means of two-dimensional (2D) homo and 3D hetero NMR experiments in combina ...

    The solution structure of recombinant Cucurbita maxima trypsin inhibitor-V (rCMTI-V), whose N-terminal is unacetylated and carries an extra glycine residue, was determined by means of two-dimensional (2D) homo and 3D hetero NMR experiments in combination with a distance geometry and simulated annealing algorithm. A total of 927 interproton distances and 123 torsion angle constraints were utilized to generate 18 structures. The root mean squared deviation (RMSD) of the mean structure is 0.53 A for main-chain atoms and 0.95 A for all the non-hydrogen atoms of residues 3-40 and 49-67. The average structure of rCMTI-V is found to be almost the same as that of the native protein [Cai, M., Gong, Y., Kao, J.-L., & Krishnamoorthi, R. (1995) Biochemistry 34, 5201-5211]. The backbone dynamics of uniformly 15N-labeled rCMTI-V were characterized by 2D 1H-15N NMR methods. 15N spin-lattice and spin-spin relaxation rate constants (R1 and R2, respectively) and [1H]-15N steady-state heteronuclear Overhauser effect enhancements were measured for the peptide NH units and, using the model-free formalism [Lipari, G., & Szabo, A. (1982) J. Am. Chem. Soc. 104, 4546-4559, 4559-4570], the following parameters were determined: overall tumbling correlation time for the protein molecule (tau m), generalized order parameters for the individual N-H vectors (S2), effective correlation times for their internal motions (tau e), and terms to account for motions on a slower time scale (second) due to chemical exchange and/or conformational averaging (R(ex)). Most of the backbone NH groups of rCMTI-V are found to be highly constrained ((S2) = 0.83) with the exception of those in the binding loop (residues 41-48, (S2) = 0.71) and the N-terminal region ((S2) = 0.73). Main-chain atoms in these regions show large RMSD values in the average NMR structure. Residues involved in turns also appear to have more mobility ((S2) = 0.80). Dynamical properties of rCMTI-V were compared with those of two other inhibitors of the potato I family--eglin c [Peng, J. W., & Wagner, G. (1992) Biochemistry 31, 8571-8586] and barley chymotrypsin inhibitor 2 [CI-2; Shaw, G. L., Davis, B., Keeler, J., & Fersht, A. R. (1995) Biochemistry 34, 2225-2233]. The Cys3-Cys48 linkage found only in rCMTI-V appears to somewhat reduce the N-terminal flexibility; likewise, the C-terminal of rCMTI-V, being part of a beta-sheet, appears to be more rigid.

    Related Citations: 
    • Investigation of Solution Conformation of Cucurbita Maxima Trypsin Inhibitor V from Pumpkin Seeds Via NMR Spectroscopy
      Cai, M., Gong, Y., Kao, J.L.F., Krishnamoorthi, R.
      (1995) Biochemistry 34: 5201
    • Chemical Synthesis, Molecular Cloning, Over Expression, and Site-Directed Mutagenesis of the Gene Coding for Pumpkin (Cucurbita Maxima) Trypsin Inhibitor Cmti-V
      Wen, L., Kim, S., Tinn, T.T., Huang, J.-K., Krishnamoorthi, R., Gong, Y., Lwin, Y.N., Kyin, S.
      (1993) Protein Expr Purif 4: 215
    • A New Protein Inhibitor of Trypsin and Activated Hageman Factor from Pumpkin (Cucurbita Maxima) Seeds
      Krishnamoorthi, R., Gong, Y., Richardson, M.
      (1990) FEBS Lett 273: 163

    Organizational Affiliation

    Department of Biochemistry, Kansas State University, Manhattan 66506, USA.

Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
TRYPSIN INHIBITOR VA69Cucurbita maximaMutation(s): 0 
Find proteins for P19873 (Cucurbita maxima)
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Go to UniProtKB:  P19873
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Submitted: 
  • OLDERADO: 1MIT Olderado

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1996-04-03
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-11-29
    Changes: Derived calculations, Other