Protein S Erlangen

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Sabine Schneider ◽  
Julian Reißig ◽  
Volker Weisbach ◽  
Susanne Achenbach ◽  
Julian Strobel ◽  
...  
Keyword(s):  
Author(s):  
G. Lembcke ◽  
F. Zemlin

The thermoacidophilic archaebacterium Sulfolobus spec. B12 , which is closely related to Sulfolobus solfataricus , possesses a regularly arrayed surface protein (S-layer), which is linked to the plasma membrane via spacer elements spanning a distinct interspace of approximately 18 nm. The S-layer has p3-Symmetry and a lattice constant of 21 nm; three-dimensional reconstructions of negatively stained fragments yield a layer thickness of approximately 6-7 nm.For analysing the molecular architecture of Sulfolobus surface protein in greater detail we use aurothioglucose(ATG)-embedding for specimen preparation. Like glucose, ATG, is supposed to mimic the effect of water, but has the advantage of being less volatile. ATG has advantages over glucose when working with specimens composed exclusively of protein because of its higher density of 2.92 g cm-3. Because of its high radiation sensitivity electromicrographs has to be recorded under strict low-dose conditions. We have recorded electromicrographs with a liquid helium-cooled superconducting electron microscope (the socalled SULEIKA at the Fritz-Haber-lnstitut) with a specimen temperature of 4.5 K and with a maximum dose of 2000 e nm-2 avoiding any pre-irradiation of the specimen.


1999 ◽  
Vol 81 (04) ◽  
pp. 527-531 ◽  
Author(s):  
U. Kjellberg ◽  
N.-E. Andersson ◽  
S. Rosén ◽  
L. Tengborn ◽  
M. Hellgren

SummaryForty-eight healthy pregnant women were studied prospectively and longitudinally. Blood sampling was performed at 10-15, 23-25, 32-34 and 38-40 weeks of gestation, within one week and at eight weeks postpartum. Classic and modified activated protein C ratio decreased as pregnancy progressed. In the third trimester 92% of the ratios measured with the classic test were above the lower reference level whereas all modified test ratios were normal. Slight activation of blood coagulation was shown with increased levels of prothrombin fragment 1+2, soluble fibrin and D-dimer. Fibrinogen, factor VIII and plasminogen activator inhibitor type 1 and type 2 increased. Protein S and tissue plasminogen activator activity decreased. Protein C remained unchanged. No correlation was found between the decrease in classic APC ratio and changes in factor VIII, fibrinogen, protein S, prothrombin fragment 1+2 or soluble fibrin, nor between the increase in soluble fibrin and changes in prothrombin fragment 1+2, fibrinogen and D-dimer.


Phlebologie ◽  
2003 ◽  
Vol 32 (02) ◽  
pp. 50-53
Author(s):  
C. Pieck ◽  
P. Sander ◽  
F. G. Bechara ◽  
P. Altmeyer ◽  
M. Stücker

ZusammenfassungKasuistik: Eine kaukasische Patientin, die sich wegen kosmetisch störender Varizen an der Bauchdecke und den Leisten vorstellte, erlitt mit 16 Jahren während einer exzessiven Tanzveranstaltung unter dem Einfluss von Ecstasy (3,4-Methylendioxymethamphetamin) aus kompletter Gesundheit bei damals asymptomatischer Vena-cava-inferior-Atresie eine akute Beckenvenenthrombose. Diagnostik: Bidirektionale Dopplersonographie, farbkodierte Duplexsonographie, Kernspintomographie mit Magnevist-Kontrastmittel der Venen beider Beine bzw. im Bereich des kleinen Beckens, Bestimmung der Serumkonzentration von Protein C und Protein S, Ausschluss von APC-Resistenz und Faktor-V-Leiden-Mutation. Ergebnisse: In der farbkodierten Duplexsonographie thrombosierte Vena iliaca externa sowie septierte, jedoch suffiziente Vena femoralis communis beidseits, keine Insuffizienzen oder Thromben in den übrigen extraund intrafaszialen Beinvenen nachweisbar. In der Kernspintomographie der Beckenvenen stellte sich eine Hypoplasie der Vena cava inferior oberhalb der Nierenetage und eine Atresie der Vena cava inferior unterhalb der Nierenetage dar sowie ein ausgeprägter venöser Kollateralkreislauf im Bereich des Beckens über die Vv. iliacae internae beidseits und die Vv. lumbales ascendentes beidseits bei varikös entarteten Kollateralvenen im Bereich der Bauchdecke beidseits mit Anschluss an die V. femoralis communis beidseits. Die untersuchten Gerinnungsparameter blieben unauffällig. Schlussfolgerung: Ecstasy-Abusus kann in Kombination mit starker körperlicher Anstrengung zu Exsikkose und Hämokonzetration führen. Dies sehen wir als letzte Ursache der Thrombose bei bestehender Vena-cava-Aplasie.


2002 ◽  
Vol 22 (02) ◽  
pp. 57-66
Author(s):  
I. Witt

ZusammenfassungDie enormen Fortschritte in der Molekularbiologie in den letzten Jahren ermöglichten sowohl die Aufklärung der Nukleotidsequenzen der Gene für Antithrombin III (AT III), Protein C (PROC) und Protein S (PROS) als auch die Identifizierung zahlreicher Mutationen bei hereditären Defekten dieser wichtigen Inhibitoren des plasmatischen Gerinnungssystems. Da die Gene für AT III (13,8 kb) und PROC (11,2 kb) nicht groß und relativ leicht zu analysieren sind, gibt es bereits umfangreiche »databases« der Mutationen (50, 73). Für AT III sind 79 und für PROC 160 unterschiedliche Mutationen beschrieben.Sowohl beim AT-III-Mangel als auch beim Protein-C-Mangel hat die Mutationsaufklärung neue Erkenntnisse über die Struktur-Funktions-Beziehung der Proteine gebracht. Beim Protein-C-Mangel steht die klinische Relevanz der DNA-Analyse im Vordergrund, da die Diagnostik des Protein-C-Mangels auf der Proteinebene nicht immer zuverlässig möglich ist.Das Protein-S-Gen ist für die Analytik schwer zugänglich, da es groß ist (80 kb) und außerdem ein Pseudogen existiert. Es sind schon zahlreiche Mutationen bei Patienten mit Protein-S-Mangel identifiziert worden. Eine Database ist bisher nicht publiziert. Die klinische Notwendigkeit zur Mutationsaufklärung besteht ebenso wie beim Protein-C-Mangel. Es ist zu erwarten, dass zukünftig die Identifizierung von Mutationen auch beim Protein-S-Mangel beschleunigt vorangeht.


1988 ◽  
Vol 59 (01) ◽  
pp. 018-022 ◽  
Author(s):  
C L Gladson ◽  
I Scharrer ◽  
V Hach ◽  
K H Beck ◽  
J H Griffin

SummaryThe frequency of heterozygous protein C and protein S deficiency, detected by measuring total plasma antigen, in a group (n = 141) of young unrelated patients (<45 years old) with venous thrombotic disease was studied and compared to that of antithrombin III, fibrinogen, and plasminogen deficiencies. Among 91 patients not receiving oral anticoagulants, six had low protein S antigen levels and one had a low protein C antigen level. Among 50 patients receiving oral anticoagulant therapy, abnormally low ratios of protein S or C to other vitamin K-dependent factors were presented by one patient for protein S and five for protein C. Thus, heterozygous Type I protein S deficiency appeared in seven of 141 patients (5%) and heterozygous Type I protein C deficiency in six of 141 patients (4%). Eleven of thirteen deficient patients had recurrent venous thrombosis. In this group of 141 patients, 1% had an identifiable fibrinogen abnormality, 2% a plasminogen abnormality, and 3% an antithrombin III deficiency. Thus, among the known plasma protein deficiencies associated with venous thrombosis, protein S and protein C. deficiencies (9%) emerge as the leading identifiable associated abnormalities.


1988 ◽  
Vol 60 (02) ◽  
pp. 328-333 ◽  
Author(s):  
N J de Fouw ◽  
Y F de Jong ◽  
F Haverkate ◽  
R M Bertina

summaryThe effect of purified human activated protein G (APC) on fibrinolysis was studied using a clot iysis system consisting of purified glu-plasminogen, tissue-type plasminogen activator, plasminogen activator inhibitor (released from endothelial cells or blood platelets), fibrinogen, 125T-fibrinogen and thrombin. All proteins were of human origin.In this system APC could increase fibrinolysis in a dose dependent way, without affecting fibrin formation or fibrin crosslinking. However, this profibrinolytic effect of APC could only be observed when plasminogen activator inhibitor (PAI-l) was present. The effect of APC was completely quenched by pretreatment of APC with anti-protein C IgG or di-isopropylfluorophosphate. Addition of the cofactors of APC:protein S, Ca2+-ions and phospholipid-alone or in combination did not enhance the profibrinolytic effect of APC. These observations indicate that human APC can accelerate in vitro clot lysis by the inactivation of PAI-1 activity. However, the neutralization of PAI-1 by APC is independent of the presence or absence of protein S, phospholipid and Ca2+-ions.


1988 ◽  
Vol 60 (02) ◽  
pp. 298-304 ◽  
Author(s):  
C A Mitchell ◽  
S M Kelemen ◽  
H H Salem

SummaryProtein S (PS) is a vitamin K-dependent anticoagulant that acts as a cofactor to activated protein C (APC). To date PS has not been shown to possess anticoagulant activity in the absence of APC.In this study, we have developed monoclonal antibody to protein S and used to purify the protein to homogeneity from plasma. Affinity purified protein S (PSM), although identical to the conventionally purified protein as judged by SDS-PAGE, had significant anticoagulant activity in the absence of APC when measured in a factor Xa recalcification time. Using SDS-PAGE we have demonstrated that prothrombin cleavage by factor X awas inhibited in the presence of PSM. Kinetic analysis of the reaction revealed that PSM competitively inhibited factor X amediated cleavage of prothrombin. PS preincubated with the monoclonal antibody, acquired similar anticoagulant properties. These results suggest that the interaction of the monoclonal antibody with PS results in an alteration in the protein exposing sites that mediate the observed anticoagulant effect. Support that the protein was altered was derived from the observation that PSM was eight fold more sensitive to cleavage by thrombin and human neutrophil elastase than conventionally purified protein S.These observations suggest that PS can be modified in vitro to a protein with APC-independent anticoagulant activity and raise the possibility that a similar alteration could occur in vivo through the binding protein S to a cellular or plasma protein.


1988 ◽  
Vol 60 (02) ◽  
pp. 182-187 ◽  
Author(s):  
Morio Aihara ◽  
Ken Tamura ◽  
Ryuko Kawarada ◽  
Keizou Okawa ◽  
Yutaka Yoshida

SummaryThe adhesion of human fixed washed platelets (FWP) to collagen was decreased after treatment with Serratia marcescens protease (SP), which removed 95% of the glycocalicin from platelet membrane glycoprotein (GP) lb. However, the diminished adhesion of SP treated FWP to collagen could still be increased in the presence of purified von Willebrand factor (vWF). This ability of vWF to increase FWP adhesion to collagen is defined as collagen cofactor (CCo). The adhesion of FWP to collagen was not affected by a monoclonal antibody (MAb) to GP Ilb/IIIa (10E5), that inhibits ADP and collagen induced platelet aggregation. On the other hand, it was decreased by 50% by a MAb to GP lb (6D1), that inhibits ristocetin induced platelet aggregation. Adhesion of FWP in buffer to collagen was completely inhibited by Ricinus communis agglutinin I or concanavalin A, while Lens culinalis agglutinin and wheat germ agglutinin showed 50% inhibition. The FWP adhesion to collagen in the presence of vWF (normal plasma) was unaffected by MAbs to GP Ilb/IIIa (10E5, P2, HPL1) but was decreased to 32-38% by MAbs to GP lb (6D1, AN51, HPL11). A MAb to vWF (CLB-RAg 35), that inhibits ristocetin induced binding of vWF to platelets, decreased the CCo of normal plasma by 70%. The MAb, CLB-RAg 201, that inhibits the binding of vWF to collagen, completely inhibited the CCo of normal plasma. In conclusion, our data suggest that (1) GP lb has a partial role in FWP adhesion to collagen; (2) the binding of vWF to collagen is required for the expression of CCo; (3) CCo is partly mediated through GP lb; but (4) other platelet membrane protein(s) besides GP lb or GP Ilb/IIIa must also be involved in FWP-vWF-collagen interactions.


1990 ◽  
Vol 64 (01) ◽  
pp. 177-178 ◽  
Author(s):  
M Zoppi ◽  
M Furlan ◽  
G Brun del Re ◽  
W Wuillemin ◽  
B Lämmle

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