1ld5

<StructureSection load='1ld5' size='340' side='right' caption='[[1ld5]], [[NMR_Ensembles_of_Models | 10 NMR models]]' scene=''>

<table><tr><td colspan='2'>[[1ld5]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Bovin Bovin]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LD5 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1LD5 FirstGlance]. <br>

</td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1ld5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ld5 OCA], [http://pdbe.org/1ld5 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1ld5 RCSB], [http://www.ebi.ac.uk/pdbsum/1ld5 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1ld5 ProSAT]</span></td></tr>

[[http://www.uniprot.org/uniprot/BPT1_BOVIN BPT1_BOVIN]] Inhibits trypsin, kallikrein, chymotrypsin, and plasmin.

<div style="background-color:#fffaf0;">

== Publication Abstract from PubMed ==

Here we determined NMR solution structures of two mutants of bovine pancreatic trypsin inhibitor (BPTI) to reveal structural reasons of their decreased thermodynamic stability. A point mutation, A16V, in the solvent-exposed loop destabilizes the protein by 20 degrees C, in contrast to marginal destabilization observed for G, S, R, L or W mutants. In the second mutant introduction of eight alanine residues at proteinase-contacting sites (residues 11, 13, 17, 18, 19, 34, 37 and 39) provides a protein that denatures at a temperature about 30 degrees C higher than expected from additive behavior of individual mutations. In order to efficiently determine structures of these variants, we applied a procedure that allows us to share data between regions unaffected by mutation(s). NOAH/DYANA and CNS programs were used for a rapid assignment of NOESY cross-peaks, structure calculations and refinement. The solution structure of the A16V mutant reveals no conformational change within the molecule, but shows close contacts between V16, I18 and G36/G37. Thus, the observed 4.3kcal/mol decrease of stability results from a strained local conformation of these residues caused by introduction of a beta-branched Val side-chain. Contrary to the A16V mutation, introduction of eight alanine residues produces significant conformational changes, manifested in over a 9A shift of the Y35 side-chain. This structural rearrangement provides about 6kcal/mol non-additive stabilization energy, compared to the mutant in which G37 and R39 are not mutated to alanine residues.

 

<div class="pdbe-citations 1ld5" style="background-color:#fffaf0;"></div>

== References ==

[[Category: Bovin]]

[[Category: Cierpicki, T]]

[[Category: Otlewski, J]]

[[Category: Bpti]]

[[Category: Kunitz fold]]