Evaluating the Effects of Fibrinogen αC Mutations on the Ability of Factor XIII to Crosslink the Reactive αC Glutamines (Q237, Q328, Q366)
Autor: | Muriel C. Maurer, Kelly Njine Mouapi, Chad A. Stephens, Lucille J. Wagner, Michael L. Merchant, Mohammed M. Hindi, Daniel W. Wilkey |
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Rok vydání: | 2019 |
Předmět: |
0301 basic medicine
Magnetic Resonance Spectroscopy Tissue transglutaminase Glutamine Plasma protein binding 030204 cardiovascular system & hematology Fibrinogen Article Fibrin Substrate Specificity 03 medical and health sciences 0302 clinical medicine Thrombin medicine Humans Binding site Blood Coagulation Factor XIII biology Chemistry Active site Hematology Peptide Fragments 030104 developmental biology Spectrometry Mass Matrix-Assisted Laser Desorption-Ionization Mutation Mutagenesis Site-Directed biology.protein Biophysics Protein Binding medicine.drug |
Zdroj: | Thromb Haemost |
ISSN: | 2567-689X 0340-6245 |
DOI: | 10.1055/s-0039-1687875 |
Popis: | Fibrinogen (Fbg) levels and extent of fibrin polymerization have been associated with various pathological conditions such as cardiovascular disease, arteriosclerosis, and coagulation disorders. Activated factor XIII (FXIIIa) introduces γ-glutamyl-ε-lysinyl isopeptide bonds between reactive glutamines and lysines in the fibrin network to form a blood clot resistant to fibrinolysis. FXIIIa crosslinks the γ-chains and at multiple sites in the αC region of Fbg. Fbg αC contains a FXIII binding site involving αC (389–402) that is located near three glutamines whose reactivities rank Q237 >> Q366 ≈ Q328. Mass spectrometry and two-dimensional heteronuclear single-quantum correlation nuclear magnetic resonance assays were used to probe the anchoring role that αC E396 may play in controlling FXIII function and characterize the effects of Q237 on the reactivities of Q328 and Q366. Studies with αC (233–425) revealed that the E396A mutation does not prevent the transglutaminase function of FXIII A2 or A2B2. Other residues must play a compensatory role in targeting FXIII to αC. Unlike full Fbg, Fbg αC (233–425) did not promote thrombin cleavage of FXIII, an event contributing to activation. With the αC (233–425) E396A mutant, Q237 exhibited slower reactivities compared with αC wild-type (WT) consistent with difficulties in directing this N-terminal segment toward an anchored FXIII interacting at a weaker binding region. Q328 and Q366 became less reactive when Q237 was replaced with inactive N237. Q237 crosslinking is proposed to promote targeting of Q328 and Q366 to the FXIII active site. FXIII thus uses Fbg αC anchoring sites and distinct Q environments to regulate substrate specificity. |
Databáze: | OpenAIRE |
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