Antithrombin III: structural and functional aspects

Mourey, Lionel; Samama, Jean‐Pierre; Delarue, M.; Choay, J; Lormeau, J C; Petitou, Maurice; Moras, Dino

doi:10.1016/0300-9084(90)90123-x

Cited by 74 publications

(35 citation statements)

References 49 publications

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“…The F-helix is involved with strands slAs3A in the sliding movement (28) that opens the A-sheet to allow the incorporation of strand s4A, shown schematically in Fig. 9, B and C. In all known serpin crystal structures (5,6,11,(29)(30)(31)(32), asparagine-187 (corresponding to Asn-158 in alantitrypsin) forms a hydrogen bond to a carbonyl group in the peptide loop that connects the F-helix to strand 3A (CL in Fig. 9).…”

Section: Discussionmentioning

confidence: 99%

Thromboembolic disease due to thermolabile conformational changes of antithrombin Rouen-VI (187 Asn-->Asp)

Bruce¹,

Perry²,

Borg³

et al. 1994

J. Clin. Invest.

154

126

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A new variant of antithrombin (Rouen-VI, 187 Asn-+Asp) with increased heparin affinity was shown to have normal inhibitory activity which decreased slowly at 4°C and rapidly at 41°C. On electrophoresis the freshly isolated variant had an anodal shift relative to native antithrombin due to the mutation. A further anodal transition occurred after either prolonged storage at 4°C or incubation at 41°C due to the formation of a new inactive uncleaved component with properties characteristic of L-form (latent) antithrombin. At the same time, polymerization also occurred with a predominance of di-, tri-, and tetra-mers. These findings fit with the observed mutation of the conserved asparagine (187) in the F-helix destabilizing the underlying A-sheet of the molecule. Evidence of A-sheet perturbation is provided by the increased rate of peptide insertion into the A-sheet and by the decreased vulnerability of the reactive loop to proteolysis. The spontaneous formation of both L-antithrombin and polymers is consistent with our crystal structure of intact antithrombin where L-form and active antithrombin are linked together as dimers. The nature of this linkage favors a mechanism of polymerization whereby the opening of the A-sheet, to give incorporation of the reactive center loop, is accompanied by the bonding of the loop of one molecule to the C-sheet of the next. The accelerated lability of antithrombin Rouen-VI at 41 versus 37°C provides an explanation for the clinical observation that episodes of thrombosis were preceded by unrelated pyrexias. (J. Clin. Invest. 1994. 94:2265-2274

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Section: Discussionmentioning

confidence: 99%

Thromboembolic disease due to thermolabile conformational changes of antithrombin Rouen-VI (187 Asn-->Asp)

Bruce¹,

Perry²,

Borg³

et al. 1994

J. Clin. Invest.

154

126

View full text Add to dashboard Cite

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“…For example, S100a9 and Mgp are calcium binding proteins and have a role in bone formation 14,15 ; Smpx plays a role in hearing and inner ear formation 16 ; C7orf62 has known links to hyperthyroidism 17 ; Myh7b has a role in the formation of cardiac muscle 18 ; and Serpinc1 regulates blood coagulation 19 . These genes could therefore be linked to convergent phenotypic traits such as changes in bone density ( S100a9, Mgp ), which is high in shallow-diving species such as the manatee and the walrus to overcome neutral buoyancy, but low in the deep-diving cetacean species that collapse their lungs to overcome neutral buoyancy.…”

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confidence: 99%

Convergent evolution of the genomes of marine mammals

et al. 2015

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Marine mammals from different mammalian orders share several phenotypic traits adapted to the aquatic environment and are therefore a classic example of convergent evolution. To investigate convergent evolution at the genomic level, we sequenced and de novo assembled the genomes of three species of marine mammals (the killer whale, walrus and manatee) from three mammalian orders that share independently evolved phenotypic adaptations to a marine existence. Our comparative genomic analyses found that convergent amino acid substitutions were widespread throughout the genome, and that a subset were in genes evolving under positive selection and putatively associated with a marine phenotype. However, we found higher levels of convergent amino acid substitutions in a control set of terrestrial sister taxa to the marine mammals. Our results suggest that while convergent molecular evolution is relatively common, adaptive molecular convergence linked to phenotypic convergence is comparatively rare.

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“…Based on the crystal structures of ATIII (14) and other serpins in cleaved (15,16) and uncleaved (17) forms, inhibition has been proposed to proceed through the recognition of the Arg 393 -Ser 394 bond in an exposed loop of ATIII as a substrate. However, upon cleavage, a conformational change in the inhibitor has been proposed to result in the trapping of the enzyme either as a tetrahedral intermediate or as an acyl-enzyme.…”

mentioning

confidence: 99%

Functional Requirements for Inhibition of Thrombin by Antithrombin III in the Presence and Absence of Heparin

Tsiang

Jain

Gibbs

1997

Journal of Biological Chemistry

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Mutation of 79 highly exposed amino acids that comprise approximately 62% of the solvent accessible surface of thrombin identified residues that modulate the inhibition of thrombin by antithrombin III, the principal physiological inhibitor of thrombin. Mutations that decreased the susceptibility of thrombin to inhibition by antithrombin III in the presence and absence of heparin (W50A, E229A, and R233A) also decreased hydrolysis of a small tripeptidyl substrate. These residues were clustered around the active site cleft of thrombin and were predicted to interact directly with the "substrate loop" of antithrombin III. Despite the large size of antithrombin III (58 kDa), no residues outside of the active cleft were identified that interact directly with antithrombin III. Mutations that decreased the susceptibility of thrombin to inhibition by antithrombin III in the presence but not in the absence of heparin (R89A/R93A/ E94A, R98A, R245A, K248A, K252A/D255A/Q256A) in general did not also affect hydrolysis of the tripeptidyl substrate. These residues were clustered among a patch of basic residues on a surface of thrombin perpendicular to the face containing the active site cleft and were predicted to interact directly with heparin. Three mutations (E25A, R178A/R180A/D183A, and E202A) caused a slight enhancement of inhibition by antithrombin III.Vascular injury or inflammation results in the activation of thrombin (1, 2). Thrombin cleaves and activates multiple substrates to mediate hemostasis through fibrin clot formation and platelet aggregation (3-7) and also regulates blood coagulation by activating the anticoagulant protein C pathway (8). The predominant mechanism for the clearance of thrombin is through inhibition by antithrombin III (ATIII), 1 a member of the family of serine protease inhibitors known as serpins (1, 9 -11). The physiological importance of this process is illustrated by the observation that individuals possessing inherited ATIII deficiency or insufficiency are subject to recurrent thrombosis (12).ATIII is a 58-kDa glycoprotein that inhibits thrombin in two kinetically distinct steps: the formation of a weak initial complex followed by rapid conversion to a stable complex (13). Based on the crystal structures of ATIII (14) and other serpins in cleaved (15, 16) and uncleaved (17) forms, inhibition has been proposed to proceed through the recognition of the Arg 393 -Ser 394 bond in an exposed loop of ATIII as a substrate. However, upon cleavage, a conformational change in the inhibitor has been proposed to result in the trapping of the enzyme either as a tetrahedral intermediate or as an acyl-enzyme. Unlike the intermediate typically formed with substrates, the intermediate formed between thrombin and ATIII is stable and resistant to hydrolysis perhaps due to the conformational change which may exclude water from the active site (9).The rate-limiting step in the inhibition of thrombin by ATIII is the formation of the initial complex (ϳ2 ϫ 10 5 M Ϫ1 min Ϫ1 ) which can be accelerated by 3 orders of...

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Antithrombin III: structural and functional aspects

Cited by 74 publications

References 49 publications

Thromboembolic disease due to thermolabile conformational changes of antithrombin Rouen-VI (187 Asn-->Asp)

Thromboembolic disease due to thermolabile conformational changes of antithrombin Rouen-VI (187 Asn-->Asp)

Convergent evolution of the genomes of marine mammals

Functional Requirements for Inhibition of Thrombin by Antithrombin III in the Presence and Absence of Heparin

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