Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
16
pubmed:dateCreated
2010-4-12
pubmed:abstractText
C1, the first component of the complement system, is a Ca(2+)-dependent heteropentamer complex of C1q and two modular serine proteases, C1r and C1s. Current functional models assume significant flexibility of the subcomponents. Noncatalytic modules in C1r have been proposed to provide the flexibility required for function. Using a recombinant CUB2-CCP1 domain pair and the individual CCP1 module, we showed that binding of Ca(2+) induces the folding of the CUB2 domain and stabilizes its structure. In the presence of Ca(2+), CUB2 shows a compact, folded structure, whereas in the absence of Ca(2+), it has a flexible, disordered conformation. CCP1 module is Ca(2+)-insensitive. Isothermal titration calorimetry revealed that CUB2 binds a single Ca(2+) with a relatively high K(D) (430 mum). In blood, the CUB2 domain of C1r is only partially (74%) saturated by Ca(2+), therefore the disordered, Ca(2+)-free form could provide the flexibility required for C1 activation. In accordance with this assumption, the effect of Ca(2+) on the autoactivation of native, isolated C1r zymogen was proved. In the case of infection-inflammation when the local Ca(2+) concentration decreases, this property of CUB2 domain could serve as subtle means to trigger the activation of the classical pathway of complement. The CUB2 domain of C1r is a novel example for globular protein domains with marginal stability, high conformational flexibility, and proteolytic sensitivity. The physical nature of the behavior of this domain is similar to that of intrinsically unstructured proteins, providing a further example of functionally relevant ligand-induced reorganization of a polypeptide chain.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-10092586, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-10775260, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-11445589, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-11673533, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-11823416, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-12429092, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-12788922, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-12960167, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-1449478, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-15207504, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-15364579, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-15769473, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-15955779, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-17052983, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-17516631, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-17544813, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-17768099, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-17996945, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-19015266, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-19180241, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-19462392, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-19473974, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-19477526, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-19494295, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-19564340, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-19783065, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-2387866, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-2557186, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-2803179, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-3021210, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-4983663, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-6204354, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-7743133, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-8042996, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-8271968, http://linkedlifedata.com/resource/pubmed/commentcorrection/20178990-9477945
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1083-351X
pubmed:author
pubmed:issnType
Electronic
pubmed:day
16
pubmed:volume
285
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11863-9
pubmed:dateRevised
2011-7-28
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Calcium-dependent conformational flexibility of a CUB domain controls activation of the complement serine protease C1r.
pubmed:affiliation
Institute of Enzymology, Hungarian Academy of Sciences, Budapest H-1113, Hungary.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't