Document Detail

X-ray structures of free and leupeptin-complexed human alphaI-tryptase mutants: indication for an alpha-->beta-tryptase transition.
MedLine Citation:
PMID:  16414069     Owner:  NLM     Status:  MEDLINE    
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.
Kerstin B Rohr; Trevor Selwood; Ulf Marquardt; Robert Huber; Norman M Schechter; Wolfram Bode; Manuel E Than
Related Documents :
21898969 - Imaging of protease functions--current guide to spotting cysteine cathepsins in classic...
19706609 - Para-nitrophenyl sulfate activation of human sulfotransferase 1a1 is consistent with in...
21722319 - Safety and efficacy of new 3,6-diaryl-7h-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazine analo...
8615699 - Inhibition of human mast cell chymase by secretory leukocyte proteinase inhibitor: enha...
16940049 - Disruption of a tight cluster surrounding tyrosine 131 in the native conformation of an...
1879379 - Inhibition of mitochondrial cholesterol side-chain cleavage by structural analogs of ch...
16402829 - Polyhydroxylated sapphyrins: multisite non-metallic catalysts for activated phosphodies...
20338189 - Endogenous thrombin potential as a novel method for the characterization of procoagulan...
16667259 - Polymorphism of a photosystem i subunit caused by alloploidy in nicotiana.
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2005-12-28
Journal Detail:
Title:  Journal of molecular biology     Volume:  357     ISSN:  0022-2836     ISO Abbreviation:  J. Mol. Biol.     Publication Date:  2006 Mar 
Date Detail:
Created Date:  2006-03-13     Completed Date:  2006-04-18     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  2985088R     Medline TA:  J Mol Biol     Country:  England    
Other Details:
Languages:  eng     Pagination:  195-209     Citation Subset:  IM    
Max-Planck-Institut für Biochemie, Abteilung Strukturforschung, Am Klopferspitz 18, 82152 Martinsried, Germany.
Data Bank Information
Bank Name/Acc. No.:
PDB/2F9N;  2F9O;  2F9P
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Amino Acid Sequence
Binding Sites
Crystallography, X-Ray
Cysteine Proteinase Inhibitors / chemistry*,  metabolism
Isoenzymes / chemistry*,  genetics,  metabolism
Leupeptins / chemistry*,  metabolism
Models, Molecular
Molecular Sequence Data
Protein Structure, Quaternary*
Recombinant Proteins / chemistry,  genetics,  metabolism
Sequence Alignment
Serine Endopeptidases / chemistry*,  genetics,  metabolism
Reg. No./Substance:
0/Cysteine Proteinase Inhibitors; 0/Isoenzymes; 0/Leupeptins; 0/Recombinant Proteins; 24365-47-7/leupeptin; EC 3.4.21.-/Serine Endopeptidases; EC

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  An unusual structure at one end of potato potyvirus particles.
Next Document:  The crystal structure of 5'-deoxy-5'-methylthioadenosine phosphorylase II from Sulfolobus solfataric...