Linked Life Data

16799156

Source:http://linkedlifedata.com/resource/pubmed/id/16799156

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
35
pubmed:dateCreated
2006-8-28
pubmed:abstractText
Tripeptidylpeptidase II (TPP II) is an exopeptidase of the subtilisin type of serine proteases, a key component of the protein degradation cascade in many eukaryotes, which cleaves tripeptides from the N terminus of proteasome-released products. The Drosophila TPP II is a large homooligomeric complex (approximately 6 MDa) that is organized in a unique repetitive structure with two strands each composed of ten stacked homodimers; two strands intertwine to form a spindle-shaped structure. We report a novel procedure of preparing an active, structurally homogeneous TPP II holo-complex overexpressed in Escherichia coli. Assembly studies revealed that the specific activity of TPP II increases with oligomer size, which in turn is strongly concentration-dependent. At a TPP II concentration such as prevailing in Drosophila, equilibration of size and activity proceeds on a time scale of hours and leads to spindle formation at a TPP II concentration of > or =0.03 mg/ml. Before equilibrium is reached, activation lags behind assembly, suggesting that activation occurs in a two-step process consisting of (i) assembly and (ii) a subsequent conformational change leading to a switch from basal to full activity. We propose a model consistent with the hyperbolic increase of activity with oligomer size. Spindle formation by strand pairing causes both significant thermodynamic and kinetic stabilization. The strands inherently heterogeneous in length are thus locked into a discrete oligomeric state. Our data indicate that the unique spindle form of the holo-complex represents an assembly motif stabilizing a highly active state.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
281
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
25723-33
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:16799156-Aminopeptidases, pubmed-meshheading:16799156-Animals, pubmed-meshheading:16799156-Cloning, Molecular, pubmed-meshheading:16799156-Cross-Linking Reagents, pubmed-meshheading:16799156-Densitometry, pubmed-meshheading:16799156-Dimerization, pubmed-meshheading:16799156-Dipeptidyl-Peptidases and Tripeptidyl-Peptidases, pubmed-meshheading:16799156-Dose-Response Relationship, Drug, pubmed-meshheading:16799156-Drosophila, pubmed-meshheading:16799156-Escherichia coli, pubmed-meshheading:16799156-Kinetics, pubmed-meshheading:16799156-Peptide Hydrolases, pubmed-meshheading:16799156-Protein Structure, Tertiary, pubmed-meshheading:16799156-Recombinant Proteins, pubmed-meshheading:16799156-Serine Endopeptidases, pubmed-meshheading:16799156-Thermodynamics, pubmed-meshheading:16799156-Time Factors
pubmed:year
2006
pubmed:articleTitle
Size matters for the tripeptidylpeptidase II complex from Drosophila: The 6-MDa spindle form stabilizes the activated state.
pubmed:affiliation
Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany.
pubmed:publicationType
Journal Article