Antithrombin III Avranches, a New Variant with Defective Serine-Protease Inhibition - Comparison with Antithrombin III Charleville

1988 ◽  
Vol 60 (01) ◽  
pp. 094-096 ◽  
Author(s):  
M Aiach ◽  
M Roncato ◽  
G Chadeuf ◽  
P Dezellus ◽  
L Capron ◽  
...  
Keyword(s):  
Antithrombin Iii ◽  
Factor Xa ◽  
Kinetic Studies ◽  
Exchange Chromatography ◽  
Protease Inhibition ◽  
Sds Page ◽  
Recurrent Venous Thromboembolism ◽  
Factor Xa Inhibition ◽  
New Variant ◽  
At Iii

SummaryA decreased plasma antithrombin activity in presence or in absence of heparin was discovered in a 47-year-old patient presenting with recurrent venous thromboembolism. The immunoreactive material (AT ΠΙ-IR) was normal. The same biological abnormalities were found in two relatives of the patient, leading to the diagnosis of hereditary qualitative AT III deficiency.The propositus’ AT III was coeluted with normal AT III from an heparin-sepharose column. An additional step of ion-exchange chromatography on a Mono Q column using a FPLC system (Pharmacia, St-Quentin en Yvelines, France) allowed the purification of a protein which was homogenous in SDS-10% polyacrylamide electrophoresis gel (PAGE). AT III purified from propositus’ plasma, normal plasma and the plasma of the patient known to have an AT III variant with defective protease binding (AT III Charleville) were compared. The specific activities measured as heparin cofactor anti thrombin or factor Xa inhibition in absence of heparin were decreased to half the normal value.Kinetic studies confirmed a decreased rate of thrombin inhibi-tion for both abnormal AT III preparations. SDS-PAGE experi-ments performed in purified system and immunoblots obtained from plasma showed that the two variants have different behaviour: in the case of AT III Charleville thrombin induced an apparent 5 Δ increase in molecular mass, probably due to a conformational change. AT III Avranches did not form stoechiometric complexes with thrombin, but was unmodified by the protease.

A NEW AT III VARIANT WITH DEFECTIVE PROTEASE BINDING SITE

1987 ◽  
Author(s):  
M Aiach ◽  
M Roncato ◽  
G Sorin ◽  
P Dezellus ◽  
J N Fiessinger
Keyword(s):  
Binding Site ◽  
Factor Xa ◽  
Normal Subjects ◽  
Exchange Chromatography ◽  
Molar Ratio ◽  
Thrombosis Research ◽  
Recurrent Venous Thromboembolism ◽  
Factor Xa Inhibition ◽  
New Variant ◽  
At Iii

A decreased plasma anti thrombin activity in presence heparin cofactor (hep-cof) or in absence of heparin (AT) was discovered in a 47 year-old patient presenting with recurrent venous thromboembolism. The immunoreactive material (AT III-IR) was normal. The same biological abnormalities were found in two relatives of the patient, leading to the diagnosis of hereditary qualitative AT III deficiency.The propositus'AT III was coeluted with normal AT III from an heparin sepharose column. An additional step of ion-exchange chromatography on a Mono Q column using a FPLC system (Pharmacia, Bois d'Arcy, France) allowed the purification of a protein which was homogenous in SDS - 10 % polyacrylamide electrophoresis gel (PAGE). AT III purified from propositus'plasma, normal plasma and the plasma of a patient known to have an AT III variant with defective protease binding (1) were compared. The specific activities measured as hep-cof AT or factor Xa inhibition in absence of heparin (anti Xa) were respectively 6.4 and 4.8 U/mg for the propositus 'AT III and 13.6 and 8.5 U/mg for the normal AT III (one unit is the activity of 1 ml of a plasma pool prepared from 30 normal subjects). The formation of protease inhibitor complexes was studied by incubating purified AT III with purified thrombin (in molar ratio 1:4, 1:2, 1:1) during 5 minutes at 37 °C and submitting the mixture to PAGE. The densitometric scan showed that in equimolar ratio the percentage of an AT III-thrombin complex (with 92 kA Mr) reaches 70 for normal AT III and respectively 30 and 23 for the propositus'AT III and the already described variant AT III Charlevillé (1). A 70 % proportion of free AT III (58 kA) remained for the propositus. As previously observed an unidentified 63 kA compound appeared for AT III Charleville. This results strongly suggest that in the patient described here, half th the AT III molecules are normal, the others having a defective protease binding site. We propose to call this new variant AT III Avranches, the town where the propositus was born.(1) Thrombosis Research 1985, 39, 559-570.

scholarly journals Antithrombin Milano: a new variant with monomeric and dimeric inactive antithrombin III

Blood ◽  
1985 ◽  
Vol 65 (2) ◽  
pp. 496-500 ◽  
Author(s):  
M Wolf ◽  
C Boyer ◽  
A Tripodi ◽  
D Meyer ◽  
MJ Larrieu ◽  
...  
Keyword(s):  
Antithrombin Iii ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Cross Reactivity ◽  
Two Dimensional ◽  
Western Blots ◽  
Sds Page ◽  
New Variant ◽  
At Iii ◽  
Monospecific Antisera

Abstract A qualitative defect of antithrombin III (AT III) has been demonstrated over three generations in eight members of an Italian family by the discrepancy between a normal amount of antigen and decreased antithrombin and anti-Xa activity in the presence or in the absence of heparin. By two-dimensional immunoelectrophoresis in the absence of heparin, two peaks of AT III were present in all patients' plasma. AT III was purified from normal and propositus plasma by sulfate dextran precipitation followed by heparin affinity chromatography. The elution profile of the patient's AT III was abnormal and allowed the separation of two populations of AT III, normal and abnormal. The first fraction (normal AT III) contained AT III activity, migrated as a single peak by two-dimensional immunoelectrophoresis and by sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE), demonstrated a single band with a molecular weight (mol wt) identical to that of normal AT III (60,000). Conversely, the last fraction, devoid of AT III activity, migrated as a single abnormal peak by two-dimensional immunoelectrophoresis in the absence of heparin. By SDS-PAGE, two bands were observed: one with a mol wt of 60,000 and a second one with a mol wt of 120,000. Western blots clearly demonstrated cross-reactivity of the 120,000 and 60,000 mol wt bands with monospecific antisera to human AT III. Reduction of the 120,000 mol wt band converted it to a single 60,000 mol wt band, suggesting the presence of an abnormal dimeric form of AT III. The name AT III Milano is proposed for this new variant.

Biochemical and Functional Study of Antithrombin III in Newborn Infants

1982 ◽  
Vol 47 (01) ◽  
pp. 056-058 ◽  
Author(s):  
M M McDonald ◽  
W E Hathaway ◽  
E B Reeve ◽  
B D Leonard
Keyword(s):  
Protein Concentration ◽  
Antithrombin Iii ◽  
Specific Activity ◽  
Newborn Infants ◽  
Factor Xa ◽  
Functional Study ◽  
Functional Studies ◽  
Sds Page ◽  
At Iii ◽  
Heparin Affinity

SummaryAntithrombin III (AT-III) was isolated by heparin affinity chromatography from adult venous and newborn term and preterm umbilical cord blood. The purified proteins were compared by SDS-PAGE, rocket immuno-electrophoresis, protein concentration by microbiuret relative to optical density at 280 nm, heparin cofactor specific activity, progressive neutralization of thrombin and factor Xa at 37°C and pH related antithrombin kinetics. The structural evaluations revealed a fetal AT-III of molecular weight, charge and electrophoretic migration indistinguishable from adult AT-III. The functional studies showed that, on an equimolar basis, the rates of thrombin and Xa interactions with fetal AT-III were as rapid as those with adult AT-III. The catalytic rates of various concentrations of heparin were also equal. The newborn infant, therefore, displays a quantitative but not qualitative deficiency of AT-III.

scholarly journals Antithrombin-III-Hamilton, Ala 382 to Thr: an antithrombin-III variant that acts as a substrate but not an inhibitor of alpha-thrombin and factor Xa

Blood ◽  
1991 ◽  
Vol 77 (10) ◽  
pp. 2185-2189
Author(s):  
RC Austin ◽  
RA Rachubinski ◽  
FA Ofosu ◽  
MA Blajchman
Keyword(s):  
Complex Formation ◽  
Serine Proteases ◽  
Antithrombin Iii ◽  
Factor Xa ◽  
Biological Behavior ◽  
Form Complex ◽  
Free System ◽  
Reactive Center ◽  
Sds Page ◽  
At Iii

Antithrombin-III-Hamilton has been shown to be a structural variant of antithrombin-III (AT-III) with normal heparin affinity but impaired protease inhibitory activity. The molecular defect of AT-III-Hamilton is the substitution of Thr for Ala at amino acid residue 382. The plasma of affected individuals contains approximately equal quantities of normal AT-III and AT-III-Hamilton. When AT-III was isolated from the plasma of the propositus by heparin-Sepharose chromatography, it had identical mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) to normal plasma-derived AT-III, under both reducing and nonreducing conditions. However, the AT-III-Hamilton species, separated from the propositus' normal AT-III by a combination of heparin-Sepharose and thrombin-Sepharose chromatography, had increased mobility on reductive SDS-PAGE compared with AT-III from the propositus isolated by heparin-Sepharose chromatography alone. Under nonreducing conditions this AT-III-Hamilton species had decreased mobility compared with AT-III from the propositus (or normal AT-III) isolated only by heparin-Sepharose chromatography. When incubated with either human alpha-thrombin or human factor Xa, this AT-III-Hamilton species was unreactive. Approximately 50% of the AT-III from the propositus isolated by heparin-Sepharose chromatography, when incubated with either human alpha-thrombin or factor Xa, did not form complex but was cleaved, presumably at the reactive center Arg393-Ser394. To further substantiate the biological behavior of this variant, AT-III- Hamilton polypeptides were synthesized in a cell-free system. This recombinantly produced AT-III-Hamilton, when incubated with either human alpha-thrombin or factor Xa, was cleaved by both these proteases, but did not show any complex formation. The results indicate that AT- III-Hamilton does not form a stable covalent inhibitory complex with these serine proteases but can be cleaved at the reactive center. Thus, the inhibition of serine proteases by their natural inhibitors (the serpins) involves at least two separate, but interrelated events; hydrolysis at the reactive center followed by complex formation. AT-III- Hamilton is capable of only the first of these events.

scholarly journals Antithrombin-III-Hamilton, Ala 382 to Thr: an antithrombin-III variant that acts as a substrate but not an inhibitor of alpha-thrombin and factor Xa

Blood ◽  
1991 ◽  
Vol 77 (10) ◽  
pp. 2185-2189 ◽  
Author(s):  
RC Austin ◽  
RA Rachubinski ◽  
FA Ofosu ◽  
MA Blajchman
Keyword(s):  
Complex Formation ◽  
Serine Proteases ◽  
Antithrombin Iii ◽  
Factor Xa ◽  
Biological Behavior ◽  
Form Complex ◽  
Free System ◽  
Reactive Center ◽  
Sds Page ◽  
At Iii

Abstract Antithrombin-III-Hamilton has been shown to be a structural variant of antithrombin-III (AT-III) with normal heparin affinity but impaired protease inhibitory activity. The molecular defect of AT-III-Hamilton is the substitution of Thr for Ala at amino acid residue 382. The plasma of affected individuals contains approximately equal quantities of normal AT-III and AT-III-Hamilton. When AT-III was isolated from the plasma of the propositus by heparin-Sepharose chromatography, it had identical mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) to normal plasma-derived AT-III, under both reducing and nonreducing conditions. However, the AT-III-Hamilton species, separated from the propositus' normal AT-III by a combination of heparin-Sepharose and thrombin-Sepharose chromatography, had increased mobility on reductive SDS-PAGE compared with AT-III from the propositus isolated by heparin-Sepharose chromatography alone. Under nonreducing conditions this AT-III-Hamilton species had decreased mobility compared with AT-III from the propositus (or normal AT-III) isolated only by heparin-Sepharose chromatography. When incubated with either human alpha-thrombin or human factor Xa, this AT-III-Hamilton species was unreactive. Approximately 50% of the AT-III from the propositus isolated by heparin-Sepharose chromatography, when incubated with either human alpha-thrombin or factor Xa, did not form complex but was cleaved, presumably at the reactive center Arg393-Ser394. To further substantiate the biological behavior of this variant, AT-III- Hamilton polypeptides were synthesized in a cell-free system. This recombinantly produced AT-III-Hamilton, when incubated with either human alpha-thrombin or factor Xa, was cleaved by both these proteases, but did not show any complex formation. The results indicate that AT- III-Hamilton does not form a stable covalent inhibitory complex with these serine proteases but can be cleaved at the reactive center. Thus, the inhibition of serine proteases by their natural inhibitors (the serpins) involves at least two separate, but interrelated events; hydrolysis at the reactive center followed by complex formation. AT-III- Hamilton is capable of only the first of these events.

An Antithrombin III Assay Based on Factor Xa Inhibition Provides a More Reliable Test to Identify Congenital Antithrombin III Deficiency Than an Assay Based on Thrombin Inhibition

1993 ◽  
Vol 69 (03) ◽  
pp. 231-235 ◽  
Author(s):  
Christine Demers ◽  
Penny Henderson ◽  
Morris A Blajchman ◽  
Michael J Wells ◽  
Lesley Mitchell ◽  
...  
Keyword(s):  
Dna Analysis ◽  
Antithrombin Iii ◽  
Polyacrylamide Gel Electrophoresis ◽  
Factor Xa ◽  
Chromogenic Substrate ◽  
Cross Sectional ◽  
Thrombin Inhibition ◽  
Factor Xa Inhibition ◽  
At Iii ◽  
The Difference

SummaryObjectives: To determine whether functional antithrombin III (AT-III) levels measured by a factor Xa inhibition (AT-III-Xa) assay identifies AT-III deficient individuals more reliably than functional AT-III levels measured by a thrombin inhibition (AT-III-IIa) assay.Study design: Cross-sectional study.Patient population: Sixty-seven members of a large family with type 2 AT-III deficiency.Intervention: DNA analysis was used as the reference diagnostic standard for AT-III status and subjects were classified as AT-III deficient or non deficient according to these results. Functional AT-III levels were measured in all subjects using: 1) a chromogenic substrate for thrombin and added human thrombin (AT-III-IIa), and 2) a chromogenic substrate for factor Xa and added bovine factor Xa (AT-III-Xa). Functional heparin cofactor II (HC-II) levels were measured using a commercially available kit. The proportions of 125I-α-thrombin complexed to AT-III and HC-II were measured by polyacrylamide gel electrophoresis and autoradiography.Results: Thirty-one (46%) individuals were classified as AT-III deficient and 36 (54%) as AT-III non deficient. AT-III-Xa assay measured a significantly lower mean AT-III value and a narrower range for individuals classified as AT-III deficient than the AT-III-IIa assay. Using the AT-III-IIa assay, six subjects had borderline AT-III levels compared to none with the AT-III-Xa assay. Thrombin inhibition by HC-II likely accounts for the AT-III-IIa assay giving higher values than the AT-III-Xa assay since 1) there was a significant correlation between the difference in AT-III-IIa and AT-III-Xa levels and HC-II levels, 2) the mean level of HC-II was significantly higher for individuals who had a positive difference between AT-III-IIa and AT-III-Xa levels compared to those who had a negative difference and 3) there was a significant correlation between the difference in AT-III-IIa and AT-III-Xa levels and the percentage of 125I-α-thrombin complexed to HC-II.Conclusion: The AT-III-Xa assay is a better discriminant between AT-III deficient and AT-III non deficient individuals than the AT-III-IIa assay.

ANTITHROMBIN III NORTHWICK PARK: CHARACTERIZATION OF AN INACTIVE HIGH MW COMPLEX WITH INCREASED AFFINITY FOR HEPARIN

1987 ◽  
Author(s):  
H Erdjument ◽  
D A Lane ◽  
A M Flynn ◽  
H Ireland ◽  
M Panico ◽  
...  
Keyword(s):  
Antithrombin Iii ◽  
Exchange Chromatography ◽  
Terminal Sequence ◽  
Structural Investigations ◽  
Crossed Immunoelectrophoresis ◽  
Sds Page ◽  
Affected Family Member ◽  
At Iii ◽  
Salt Gradient

It has been shown previously that antithrombin III Northwick Park (AT III NWP) has reduced ability to inactivate thrombin and is characterised by an additional anodal component on crossed immunoelectrophoresis. We have applied plasma from an affected family member to heparin-Sepharose and eluted the AT III with a salt gradient. Evidence will be presented that the anodal component has* higher affinity for heparin than normal AT III. Furthermore, this variant component is present in plasma as a MW >120,000 inactive complex whose tryptic peptide FAB map contains numerous signals not characteristic of normal AT . 111 . This complex can be reduced with dithiothreitol to two non identical bands on SDS PAGE with MW ~60,000, only one of which reacts with anti-AT III. Using ion-exchange chromatography and HPLC these two components have been isolated and separated. The N-terminal sequence of the protein that does not react with anti-AT III is believed to be Asp-Ala-His-Ile-Ser-Glu. Structural investigations on the variant AT III are underway.

Increased concentrations of heparin cofactor II in diabetic patients, and possible effects on thrombin inhibition assay of antithrombin III.

1989 ◽  
Vol 35 (1) ◽  
pp. 52-55 ◽  
Author(s):  
J Gram ◽  
J Jespersen
Keyword(s):  
Antithrombin Iii ◽  
Factor Xa ◽  
Diabetic Patients ◽  
Type I ◽  
Inhibition Assay ◽  
Heparin Cofactor Ii ◽  
Thrombin Inhibition ◽  
Factor Xa Inhibition ◽  
At Iii ◽  
High Concentrations

Abstract We compared concentrations of antithrombin III (AT-III) in plasma, as determined by an immunological method and by a functional thrombin inhibition method, in the presence of heparin in 160 blood samples from Type I diabetics. Although the correlation was highly significant (P less than 0.001) between the results obtained by the two methods, our data demonstrated that results by the thrombin inhibition assay, 121 (SD 15)%, expressed as percentages of the results for a normal plasma pool, were significantly (P less than 0.001) higher than by the immunoreactive method, 104 (SD 15)%, indicating an overestimation of functionally active AT-III. Concentrations of functionally active AT-III determined by a factor Xa inhibition assay, 105 (SD 13)%, were in the same range as immunoreactive AT-III. Addition of IgG antiserum to normal pooled plasma quenched only about 90% of the AT-III activity determined by the thrombin inhibition assay, but all of the AT-III activity determined by a factor Xa inhibition assay. These results demonstrate that the factor Xa inhibition assay is more specific for the determination of AT-III than the thrombin inhibition assay. We suggest that the high concentrations of heparin cofactor II, 117 (SD 17)%, might have caused an overestimation of AT III in this group of patients with diabetes Type I, and should not be overlooked in other clinical situations.

scholarly journals Antithrombin Milano: a new variant with monomeric and dimeric inactive antithrombin III

Blood ◽  
1985 ◽  
Vol 65 (2) ◽  
pp. 496-500
Author(s):  
M Wolf ◽  
C Boyer ◽  
A Tripodi ◽  
D Meyer ◽  
MJ Larrieu ◽  
...  
Keyword(s):  
Antithrombin Iii ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Cross Reactivity ◽  
Two Dimensional ◽  
Western Blots ◽  
Sds Page ◽  
New Variant ◽  
At Iii ◽  
Monospecific Antisera

A qualitative defect of antithrombin III (AT III) has been demonstrated over three generations in eight members of an Italian family by the discrepancy between a normal amount of antigen and decreased antithrombin and anti-Xa activity in the presence or in the absence of heparin. By two-dimensional immunoelectrophoresis in the absence of heparin, two peaks of AT III were present in all patients' plasma. AT III was purified from normal and propositus plasma by sulfate dextran precipitation followed by heparin affinity chromatography. The elution profile of the patient's AT III was abnormal and allowed the separation of two populations of AT III, normal and abnormal. The first fraction (normal AT III) contained AT III activity, migrated as a single peak by two-dimensional immunoelectrophoresis and by sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE), demonstrated a single band with a molecular weight (mol wt) identical to that of normal AT III (60,000). Conversely, the last fraction, devoid of AT III activity, migrated as a single abnormal peak by two-dimensional immunoelectrophoresis in the absence of heparin. By SDS-PAGE, two bands were observed: one with a mol wt of 60,000 and a second one with a mol wt of 120,000. Western blots clearly demonstrated cross-reactivity of the 120,000 and 60,000 mol wt bands with monospecific antisera to human AT III. Reduction of the 120,000 mol wt band converted it to a single 60,000 mol wt band, suggesting the presence of an abnormal dimeric form of AT III. The name AT III Milano is proposed for this new variant.

Reactivity of a Hereditary Abnormal Antithrombin III Fraction in the Inhibition of Thrombin and Factor Xa

1980 ◽  
Vol 44 (02) ◽  
pp. 092-095 ◽  
Author(s):  
T H Tran ◽  
C Bondeli ◽  
G A Marbet ◽  
F Duckert
Keyword(s):  
Antithrombin Iii ◽  
Factor Xa ◽  
Heparin Binding ◽  
Thrombin Inhibition ◽  
Superficial Thrombophlebitis ◽  
Heparin Concentration ◽  
Heparin Binding Site ◽  
At Iii ◽  
The Difference ◽  
Inhibition Of Thrombin

SummaryTwo different AT-III fractions were purified from the plasma of a patient with recurrent superficial thrombophlebitis. The abnormal AT-III fraction (A-AT) was compared to the normal AT-III fraction (N-AT) in the inhibition of thrombin and factor Xa. Without heparin, both inactivate proteases in a similar manner and at the same rate. However, at low heparin concentration the thrombin inhibition proceeds more slowly with A-AT than with N-AT. At high heparin concentration the difference between A-AT and N-AT becomes very small. The inhibition of factor Xa follows a similar pattern. It is suggested that the heparin binding site of A-AT differs from that of N-AT resulting in a decreased heparin cofactor activity.

Sign in / Sign up

Export Citation Format

Share Document