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Activated protein C cofactor function of protein S: a critical role for Asp95 in the EGF1-like domain

Andersson, Helena M.; Arantes, Marcia J.; Crawley, James T. B.; Luken, Brenda M.; Tran, Sinh LU ; Dahlbäck, Björn LU ; Lane, David A. and Rezende, Suely M. (2010) In Blood 115(23). p.4878-4885
Abstract
Protein S has an established role in the protein C anticoagulant pathway, where it enhances the factor Va (FVa) and factor VIIIa (FVIIIa) inactivating property of activated protein C (APC). Despite its physiological role and clinical importance, the molecular basis of its action is not fully understood. To clarify the mechanism of the protein S interaction with APC, we have constructed and expressed a library of composite or point variants of human protein S, with residue substitutions introduced into the Gla, thrombin-sensitive region (TSR), epidermal growth factor 1 (EGF1), and EGF2 domains. Cofactor activity for APC was evaluated by calibrated automated thrombography (CAT) using protein S-deficient plasma. Of 27 variants tested... (More)
Protein S has an established role in the protein C anticoagulant pathway, where it enhances the factor Va (FVa) and factor VIIIa (FVIIIa) inactivating property of activated protein C (APC). Despite its physiological role and clinical importance, the molecular basis of its action is not fully understood. To clarify the mechanism of the protein S interaction with APC, we have constructed and expressed a library of composite or point variants of human protein S, with residue substitutions introduced into the Gla, thrombin-sensitive region (TSR), epidermal growth factor 1 (EGF1), and EGF2 domains. Cofactor activity for APC was evaluated by calibrated automated thrombography (CAT) using protein S-deficient plasma. Of 27 variants tested initially, only one, protein S D95A (within the EGF1 domain), was largely devoid of functional APC cofactor activity. Protein S D95A was, however, gamma-carboxylated and bound phospholipids with an apparent dissociation constant (Kd(app)) similar to that of wildtype (WT) protein S. In a purified assay using FVa R506Q/R679Q, purified protein S D95A was shown to have greatly reduced ability to enhance APC-induced cleavage of FVa Arg306. It is concluded that residue Asp95 within EGF1 is critical forAPC cofactor function of protein S and could define a principal functional interaction site for APC. (Blood. 2010;115(23):4878-4885) (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Blood
volume
115
issue
23
pages
4878 - 4885
publisher
American Society of Hematology
external identifiers
  • wos:000278635900036
  • scopus:77954707351
ISSN
1528-0020
DOI
10.1182/blood-2009-11-256610
language
English
LU publication?
yes
id
1fdd62b1-df73-485c-b248-01dd724c47b7 (old id 1760680)
date added to LUP
2011-02-18 14:59:53
date last changed
2018-05-29 11:05:31
@article{1fdd62b1-df73-485c-b248-01dd724c47b7,
  abstract     = {Protein S has an established role in the protein C anticoagulant pathway, where it enhances the factor Va (FVa) and factor VIIIa (FVIIIa) inactivating property of activated protein C (APC). Despite its physiological role and clinical importance, the molecular basis of its action is not fully understood. To clarify the mechanism of the protein S interaction with APC, we have constructed and expressed a library of composite or point variants of human protein S, with residue substitutions introduced into the Gla, thrombin-sensitive region (TSR), epidermal growth factor 1 (EGF1), and EGF2 domains. Cofactor activity for APC was evaluated by calibrated automated thrombography (CAT) using protein S-deficient plasma. Of 27 variants tested initially, only one, protein S D95A (within the EGF1 domain), was largely devoid of functional APC cofactor activity. Protein S D95A was, however, gamma-carboxylated and bound phospholipids with an apparent dissociation constant (Kd(app)) similar to that of wildtype (WT) protein S. In a purified assay using FVa R506Q/R679Q, purified protein S D95A was shown to have greatly reduced ability to enhance APC-induced cleavage of FVa Arg306. It is concluded that residue Asp95 within EGF1 is critical forAPC cofactor function of protein S and could define a principal functional interaction site for APC. (Blood. 2010;115(23):4878-4885)},
  author       = {Andersson, Helena M. and Arantes, Marcia J. and Crawley, James T. B. and Luken, Brenda M. and Tran, Sinh and Dahlbäck, Björn and Lane, David A. and Rezende, Suely M.},
  issn         = {1528-0020},
  language     = {eng},
  number       = {23},
  pages        = {4878--4885},
  publisher    = {American Society of Hematology},
  series       = {Blood},
  title        = {Activated protein C cofactor function of protein S: a critical role for Asp95 in the EGF1-like domain},
  url          = {http://dx.doi.org/10.1182/blood-2009-11-256610},
  volume       = {115},
  year         = {2010},
}