Functional characterization of an abnormal factor XII molecule (F XII Bern)

Blood ◽  
1991 ◽  
Vol 78 (4) ◽  
pp. 997-1004
Author(s):  
WA Wuillemin ◽  
I Huber ◽  
M Furlan ◽  
B Lammle

An 18-year-old healthy woman was found to have cross-reacting material (CRM)-positive factor XII (F XII) deficiency, F XII clotting activity was less than 0.01 U/mL, whereas F XII antigen was 0.11 U/mL. An F XII inhibitor was excluded. To partially characterize the molecular defect of the abnormal F XII, immunologic and functional studies were performed on the proposita's plasma. The abnormal F XII was a single chain molecule with the same molecular weight (80 Kd) and the same isoelectric points (pl, 5.9 to 6.8) as normal F XII. Dextran sulfate activation of the proposita's plasma showed no proteolytic cleavage of F XII even after 120 minutes, whereas F XII in pooled normal plasma, diluted 1:10 with CRM-negative F XII-deficient plasma, was completely cleaved after 40 minutes. Adsorption to kaolin was identical for both abnormal and normal F XII. In the presence of dextran sulfate and exogenous plasma kallikrein, the abnormal F XII was cleaved with the same rate as normal F XII. However, kallikrein-cleaved abnormal F XII was not able to cleave factor XI and plasma prekallikrein, in contrast to activated normal F XII. Thus, these studies show that the functional defect of this abnormal F XII, denoted as F XII Bern, is due to the lack of protease activity of the kallikrein-cleaved molecule. Therefore, the structural defect is likely to be located in the light chain region of F XII, containing the enzymatic active site.

Blood ◽  
1991 ◽  
Vol 78 (4) ◽  
pp. 997-1004 ◽  
Author(s):  
WA Wuillemin ◽  
I Huber ◽  
M Furlan ◽  
B Lammle

Abstract An 18-year-old healthy woman was found to have cross-reacting material (CRM)-positive factor XII (F XII) deficiency, F XII clotting activity was less than 0.01 U/mL, whereas F XII antigen was 0.11 U/mL. An F XII inhibitor was excluded. To partially characterize the molecular defect of the abnormal F XII, immunologic and functional studies were performed on the proposita's plasma. The abnormal F XII was a single chain molecule with the same molecular weight (80 Kd) and the same isoelectric points (pl, 5.9 to 6.8) as normal F XII. Dextran sulfate activation of the proposita's plasma showed no proteolytic cleavage of F XII even after 120 minutes, whereas F XII in pooled normal plasma, diluted 1:10 with CRM-negative F XII-deficient plasma, was completely cleaved after 40 minutes. Adsorption to kaolin was identical for both abnormal and normal F XII. In the presence of dextran sulfate and exogenous plasma kallikrein, the abnormal F XII was cleaved with the same rate as normal F XII. However, kallikrein-cleaved abnormal F XII was not able to cleave factor XI and plasma prekallikrein, in contrast to activated normal F XII. Thus, these studies show that the functional defect of this abnormal F XII, denoted as F XII Bern, is due to the lack of protease activity of the kallikrein-cleaved molecule. Therefore, the structural defect is likely to be located in the light chain region of F XII, containing the enzymatic active site.


1992 ◽  
Vol 67 (02) ◽  
pp. 219-225 ◽  
Author(s):  
Walter A Wuillemin ◽  
Miha Furlan ◽  
Hans Stricker ◽  
Bernhard Lämmle

SummaryThe plasma of a healthy woman was found to contain half normal factor XII (FXII) antigen level (0.46 U/ml) without any FXII clotting activity (<0.01 U/ml). The variant FXII in this plasma, denoted as FXII Locarno, was partially characterized by immunological and functional studies on the proposita’s plasma. FXII Locarno is a single chain molecule with the same size (M r = 80 kDa) as normal FXII. Isoelectric focusing suggested an excess of negative charge in the variant FXII as compared to normal FXII. In contrast to FXII in normal plasma, FXII Locarno was not proteolytically cleaved upon prolonged incubation of proposita’s plasma with dextran sulfate. Adsorption to kaolin was similar for both, abnormal and normal FXII. Incubation of the proposita’s plasma with dextran sulfate and exogenous plasma kallikrein showed normal cleavage of FXII Locarno outside of the tentative disulfide loop Cys340-Cys467, but only partial cleavage within this disulfide loop. Furthermore, plasma kallikrein-cleaved abnormal FXII showed neither amidolytic activity nor proteolytic activity against factor XI and plasma prekallikrein.These results suggest a structural alteration of FXII Locarno, affecting the plasma kallikrein cleavage site Arg353-Val354 and thus formation of activated FXII (a-FXIIa).


1993 ◽  
Vol 70 (03) ◽  
pp. 427-432 ◽  
Author(s):  
W A Wuillemin ◽  
M Furlan ◽  
A von Felten ◽  
B Lämmle

SummaryThe plasma of a 68-year-old man with cross reacting material (CRM)-positive prekallikrein (PK) deficiency was studied. PK clotting activity was <0.01 U/ml, and PK antigen was 0.1 U/ml. No circulating anticoagulant against PK was detectable. The abnormal PK molecule, denoted as prekallikrein Zürich, was partially characterized by immunological and functional studies on the propositus’ plasma. Immunobiotting analysis showed the abnormal PK being a single chain molecule of the same M r (80 kDa) as normal PK. Dextran sulfate activation of the propositus’ plasma did not lead to proteolytic cleavage of the variant PK molecule, in contrast to dextran sulfate activation of a mixture of 1 volume normal plasma and 9 volumes CRM-negative PK deficient plasma. Agarose gel electrophoresis followed by immunoblotting demonstrated that PK Zürich was complexed with high molecular weight kininogen similarly to PK in normal plasma. Incubation of the propositus’ plasma with purified β-FXIIa resulted in impaired cleavage of PK Zürich when compared with PK hydrolysis in a mixture of 10% normal plasma and 90% CRM-negative PK deficient plasma. Moreover, proteolytically cleaved PK Zürich showed no enzymatic activity against factor XII and high molecular weight kininogen.These studies show that the functional defect of prekallikrein Zürich is due to an impaired cleavage by activated factor XII and probably the lack of enzymatic activity of the cleaved variant molecule.


Blood ◽  
1994 ◽  
Vol 84 (4) ◽  
pp. 1173-1181 ◽  
Author(s):  
JK Hovinga ◽  
J Schaller ◽  
H Stricker ◽  
WA Wuillemin ◽  
M Furlan ◽  
...  

The dysfunctional coagulation factor XII (FXII) Locarno was purified from 2 L of the proposita's plasma. Studies to identify the molecular defect responsible for the lack of amidolytic and proteolytic activity of this FXII variant were performed. Amino acid sequence analysis of peptides obtained from FXII Locarno on activation with either trypsin or plasma kallikrein and dextran sulfate showed an amino acid substitution of Arg 353 by Pro. Thereby, the kallikrein cleavage site at Arg 353-Val 354 is lost. Although trypsin-activated FXII Locarno was fully cleaved at Arg 334-Asn 335 and at Arg 343-Leu 344, neither amidolytic nor proteolytic activity was generated. We conclude that proteolytic cleavage at Arg 343 in the absence of cleavage at Arg 353 is not sufficient to expose the enzymatic active site in FXII Locarno.


Blood ◽  
1994 ◽  
Vol 84 (4) ◽  
pp. 1173-1181 ◽  
Author(s):  
JK Hovinga ◽  
J Schaller ◽  
H Stricker ◽  
WA Wuillemin ◽  
M Furlan ◽  
...  

Abstract The dysfunctional coagulation factor XII (FXII) Locarno was purified from 2 L of the proposita's plasma. Studies to identify the molecular defect responsible for the lack of amidolytic and proteolytic activity of this FXII variant were performed. Amino acid sequence analysis of peptides obtained from FXII Locarno on activation with either trypsin or plasma kallikrein and dextran sulfate showed an amino acid substitution of Arg 353 by Pro. Thereby, the kallikrein cleavage site at Arg 353-Val 354 is lost. Although trypsin-activated FXII Locarno was fully cleaved at Arg 334-Asn 335 and at Arg 343-Leu 344, neither amidolytic nor proteolytic activity was generated. We conclude that proteolytic cleavage at Arg 343 in the absence of cleavage at Arg 353 is not sufficient to expose the enzymatic active site in FXII Locarno.


1992 ◽  
Vol 67 (04) ◽  
pp. 440-444 ◽  
Author(s):  
Hiroko Tsuda ◽  
Toshiyuki Miyata ◽  
Sadaaki Iwanaga ◽  
Tetsuro Yamamoto

SummaryThe analysis of normal human plasma by fibrin autography revealed four species of plasminogen activator (PA) activity related to tissue-type PA, factor XII, prekallikrein and urokinase-type PA (u-PA). The u-PA activity increased significantly by incubating plasma with dextran sulfate. This increase was coincident with both the cleavage of factor XII and the complex formation of activated factor XII with its plasma inhibitors, which were determined by immunoblotting procedure. The dextran sulfate-dependent activation of u-PA required both factor XII and prekallikrein, but did not require either plasminogen or factor XI. High molecular weight kininogen was required only at a low concentration of dextran sulfate. Thus the results indicate that the factor XII and prekallikrein-mediated activation of single chain u-PA (scu-PA) operates as a major pathway of scu-PA activation in whole plasma in contact with dextran sulfate.


2015 ◽  
Vol 308 (2) ◽  
pp. C123-C138 ◽  
Author(s):  
E. Giacomello ◽  
M. Quarta ◽  
C. Paolini ◽  
R. Squecco ◽  
P. Fusco ◽  
...  

Muscle-specific ankyrins 1 (sAnk1) are a group of small ankyrin 1 isoforms, of which sAnk1.5 is the most abundant. sAnk1 are localized in the sarcoplasmic reticulum (SR) membrane from where they interact with obscurin, a myofibrillar protein. This interaction appears to contribute to stabilize the SR close to the myofibrils. Here we report the structural and functional characterization of skeletal muscles from sAnk1 knockout mice (KO). Deletion of sAnk1 did not change the expression and localization of SR proteins in 4- to 6-mo-old sAnk1 KO mice. Structurally, the main modification observed in skeletal muscles of adult sAnk1 KO mice (4–6 mo of age) was the reduction of SR volume at the sarcomere A band level. With increasing age (at 12–15 mo of age) extensor digitorum longus (EDL) skeletal muscles of sAnk1 KO mice develop prematurely large tubular aggregates, whereas diaphragm undergoes significant structural damage. Parallel functional studies revealed specific changes in the contractile performance of muscles from sAnk1 KO mice and a reduced exercise tolerance in an endurance test on treadmill compared with control mice. Moreover, reduced Qγcharge and L-type Ca2+current, which are indexes of affected excitation-contraction coupling, were observed in diaphragm fibers from 12- to 15-mo-old mice, but not in other skeletal muscles from sAnk1 KO mice. Altogether, these findings show that the ablation of sAnk1, by altering the organization of the SR, renders skeletal muscles susceptible to undergo structural and functional alterations more evident with age, and point to an important contribution of sAnk1 to the maintenance of the longitudinal SR architecture.


2014 ◽  
Vol 12 (8) ◽  
pp. 1098-1107 ◽  
Author(s):  
Huafang Lai ◽  
Junyun He ◽  
Jonathan Hurtado ◽  
Jake Stahnke ◽  
Anja Fuchs ◽  
...  

2015 ◽  
Vol 396 (8) ◽  
pp. 903-915 ◽  
Author(s):  
Nazhat Shirzad-Wasei ◽  
Jenny van Oostrum ◽  
Petra H.M. Bovee-Geurts ◽  
Lisanne J.A. Kusters ◽  
Giel J.C.G.M. Bosman ◽  
...  

Abstract Structural and functional characterization of integral membrane proteins in a bilayer environment is strongly hampered by the requirement of detergents for solubilization and subsequent purification, as detergents commonly affect their structure and/or activity. Here, we describe a rapid procedure with minimal exposure to detergent to directly assemble an overexpressed integral membrane protein into soluble lipid nanodiscs prior to purification. This is exemplified with recombinant his-tagged rhodopsin, which is rapidly extracted from its host membrane and directly assembled into membrane scaffold protein (MSP) nanodiscs. We further demonstrate that, even when the MSP was his-tagged as well, partial purification of the rhodopsin-nanodiscs could be achieved exploiting immobilized-metal chromatography. Recoveries of rhodopsin up to 80% were achieved in the purified nanodisc fraction. Over 95% of contaminating membrane protein and his-tagged MSP could be removed from the rhodopsin-nanodiscs using a single Ni2+-affinity chromatography step. This level of purification is amply sufficient for functional studies. We provide evidence that the obtained rhodopsin-nanodisc preparations are fully functional both photochemically and in their ability to bind the cognate G-protein.


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