Preparation of Recombinant Centromeric Nucleosomes and Formation of Complexes with Nonhistone Centromere Proteins

2016 ◽  
pp. 67-96 ◽  
Author(s):  
N. Sekulic ◽  
B.E. Black
Keyword(s):  
Centromere Proteins ◽  
Formation Of Complexes

Mutations which Introduce Free Cysteine Residues in the Gla-Domain of Vitamin K Dependent Proteins Result in the Formation of Complexes with α1-Microglobulin

1996 ◽  
Vol 75 (01) ◽  
pp. 070-075 ◽  
Author(s):  
E G C Wojcik ◽  
P Simioni ◽  
M v d Berg ◽  
A Girolami ◽  
R M Bertina
Keyword(s):  
Vitamin K ◽  
Protein C ◽  
Cysteine Residue ◽  
Factor Ix ◽  
Disulphide Bond ◽  
Clotting Factors ◽  
High Molecular Weight Complex ◽  
Low Concentrations ◽  
Gla Domain ◽  
Formation Of Complexes

SummaryWe have previously described a genetic factor IX variant (Cys18→Arg) for which we demonstrated that it had formed a heterodimer with armicroglobulin through formation of a disulphide bond with the remaining free cysteine residue of the disrupted disulphide bond in the Gla-domain of factor IX. Recently, we observed a similar high molecular weight complex for a genetic protein C variant (Arg-1→Cys). Both the factor IX and the protein C variants have a defect in the calcium induced conformation. In this study we show that the aminoterminus of this protein C variant is prolonged with one amino acid, cysteine. This protein C variant, as well as protein C variants with Arg9→Cys and Ser12→Cys mutations which also carry a free cysteine residue, are shown to be present in plasma as a complex with α1-microglobulin. A prothrombin variant with a Tyr44→Cys mutation, had not formed such a complex. Furthermore, complexes between normal vitamin K-dependent clotting factors and α1-microglobulin were shown to be present in plasma at low concentrations. The data suggest that the presence of an unpaired cysteine residue in the propeptide or the N-terminal half of the Gla-domain has strongly promoted the formation of a complex with α1-microglobulin in the variants.

Western Blot Analyses of Prekallikrein and its Activation Products in Human Plasma

1991 ◽  
Vol 65 (04) ◽  
pp. 382-388 ◽  
Author(s):  
Dulce Veloso ◽  
Robert W Colman
Keyword(s):  
Complex Formation ◽  
Western Blot ◽  
Human Plasma ◽  
Contact System ◽  
Plasma Activation ◽  
Normal Plasma ◽  
Sds Page ◽  
Activation Products ◽  
Major Antigen ◽  
Formation Of Complexes

SummaryPrekallikrein (PK), a zymogen of the contact system, and its activation products, kallikrein (KAL), KAl-inhibitor complexes and fragments containing KAL epitope(s) have been detected in human plasma by immunoblotting with a monoclonal anti-human plasma PK antibody, MAb 13G1L. Detection of antigen-MAb 13G11 complexes with peroxidase-conjugated anti-IgG showed that the two variants of PK (85- and 88-kDa) are the only major antigen species in normal, non-activated plasma. Upon plasma activation with kaolin, the intensity of the PK bands decreased with formation of complexes of KAL with CL inhibitor (C1 INH) and α2-rrtzcroglobulin (α2M) identical to those formed by the purified proteins. Immunoblots of normal plasma showed good correlation between the PK detected and the amount of plasma assayed. Increasing amounts of KAL incubated with a constant volume of PK-deficient plasma showed increasing amounts of KAL and of KAL-C1 INH and KAL-α2M complexes. Complexes of KALantithrombin III (ATIII) and the ratio of KALα2M/ KAL-CL INH were higher in activated CL INH-deficient plasmas than in activated normal plasmas. Protein resolution by 3-12% gradient SDS-PAGE and epitope detection with [125I]MAb 13G11 showed four KALα2M species and a 45-kDa fragment(s) in both surface-activated normal plasma and complexes formed by purified KAL and α2M. Immunoblots of activated plasma also showed bands at the position of KALCL INH and KALATIII complexes. When α1-antitrypsin Pittsburgh (cα1-AT, Pitts) was added to plasma before activation, KAL-α1-ALPitts was the main complex. The non-activated normal plasma revealed only an overloaded PK band. This is the first report of an antibody that recognizes KAL epitope(s) in KAL-α2M, KALATIII and KALa1-α1Pitts complexes and in the 45-kDa fragment(s). Therefore, MAb 13G11 should be useful for studying the structure of these complexes as well as the mechanism of complex formation. In addition, immunoblotting with MAb 13G11 would allow detection of KAl-inhibitor complexes in patient plasmas as indicators of activation of the contact system.

scholarly journals Expression of inter-alpha-trypsin inhibitor heavy chains in endometrium of cyclic and pregnant gilts

Reproduction ◽  
2003 ◽  
pp. 621-627 ◽  
Author(s):  
RD Geisert ◽  
MD Ashworth ◽  
Keyword(s):  
Gene Expression ◽  
Extracellular Matrix ◽  
Western Blot ◽  
Protease Inhibitor ◽  
Early Pregnancy ◽  
Trypsin Inhibitor ◽  
Serine Protease Inhibitor ◽  
Oestrous Cycle ◽  
Heavy Chains ◽  
Formation Of Complexes

Attachment of the placenta to the uterus in pigs involves extracellular interaction between the expanding trophoblastic membrane and the thick glycocalyx present on the uterine epithelial microvilli. Formation of complexes between members of inter-alpha-trypsin inhibitor family may function in the maintenance of the extracellular matrix. This study investigated the change in the inter-alpha-trypsin inhibitor heavy chains (ITIH1, ITIH2, ITIH3 and ITIH4) during the oestrous cycle and early pregnancy in pigs. Gene expression of ITIH1, ITIH2, ITIH3 and ITIH4 was detected in the endometrium of cyclic and pregnant gilts; however, gene expression of ITIH was not altered throughout the oestrous cycle or early pregnancy. Western blot analysis with an ITIH antiserum identified the possible linkage forms of ITIH with the serine protease inhibitor, bikunin. Pregnancy altered the release of the various inter-alpha-inhibitor forms from the endometrium during the period of trophoblastic attachment. The results from this study indicate that the inter-alpha-trypsin inhibitor family plays an important role in maintenance of the uterine surface glycocalyx during placental attachment in pigs.

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