The binding of Mn2+ to bovine plasma protein C, des(1–41)-light chain protein C, and activated des(1–41)-light chain activated protein C

1987 ◽  
Vol 254 (1) ◽  
pp. 196-202 ◽  
Author(s):  
Kelvin A.W. Hill ◽  
Francis J. Castellino
Keyword(s):  
Plasma Protein ◽  
Light Chain ◽  
Protein C ◽  
Activated Protein C ◽  
Bovine Plasma

scholarly journals Estimation of the distance between the divalent cation binding site of des-1-41-light chain-activated bovine plasma protein C and a nitroxide spin label attached to the active-site serine residue

1988 ◽  
Vol 251 (1) ◽  
pp. 229-236 ◽  
Author(s):  
K A W Hill ◽  
S A Steiner ◽  
F J Castellino
Keyword(s):  
Light Chain ◽  
Active Site ◽  
Spin Label ◽  
Protein C ◽  
Activated Protein C ◽  
Cation Binding ◽  
Serine Residue ◽  
Paramagnetic Effect ◽  
Cation Binding Site ◽  
Bovine Plasma

The paramagnetic effect of Mn2+ on the electron paramagnetic resonance spectrum of a nitroxide spin label covalently attached to the active-site serine residue of des-1-41-light chain bovine plasma-activated protein C, and situated at a distance of approximately 1.2 nm from this amino acid, has been utilized to estimate the distance on the enzyme surface between the single Mn2+ site and the free electron of the spin label. This distance has been found to be approx. 1.12 nm. A significant paramagnetic effect of Mn2+ on the spectrum of this same nitroxide spin label bound to activated protein C (APC) has been found. However, in this case distance calculations are complicated by the existence of a multiplicity of Mn2+ sites on APC. If it is assumed that a single Mn2+ site is responsible for the paramagnetic effect on the spectrum of the spin label, the interelectron distance on APC would be approx. 0.90 nm.

Anticoagulant properties of bovine plasma protein C following activation by thrombin

Biochemistry ◽  
1977 ◽  
Vol 16 (26) ◽  
pp. 5824-5831 ◽  
Author(s):  
Walter Kisiel ◽  
William M. Canfield ◽  
Lowell H. Ericsson ◽  
Earl W. Davie
Keyword(s):  
Plasma Protein ◽  
Protein C ◽  
Bovine Plasma

Determination of Protein C Antigen Levels in Hospitalized Patients with Blood Coagulative Defects

2021 ◽  
Vol 2 (1) ◽  
pp. 1-04
Author(s):  
George Zhu
Keyword(s):  
Plasma Protein ◽  
Protein C ◽  
Activated Protein C ◽  
Protein S ◽  
Promyelocytic Leukemia ◽  
Hospitalized Patients ◽  
Cancer Cell Proliferation ◽  
Healthy Individuals ◽  
Acute Leukemias

Protein C, a vitamin K-dependent anticoagulant serine protease, is involved in blood coagulation. Activated protein C inactivates Va and VIIIa in purified protein systems and stimulates fibrinolysis by indirectly increasing the level of circulating plasminogen activator. In this process, protein S serve as an important factor for activated protein C. In recent years, excess protein S drives cancer cell proliferation and cell survival through oncogenic receptor Axl (Anexelekto). We determined changes of plasma protein C antigen by using rocket immunoassay both in 50 healthy individuals and 103 distinct hospitalized patients. In healthy individuals protein C antigen(PC:Ag) ranges o.6439- 1.4752 µ/ml. The results showed that plasma protein C antigen was considerably high in 22 diabetes mellitus. In contrast, the PC:Ag was significantly decreased in 19 liver cirrhosis(p< 0.001) and in closely line with serum albumin levels(p< 0.05). In 31 acute leukemias, on the average, there was slightly lower values in PC:Ag, and accompanied with the distribution of significant decrease of PC:Ag values in 5 FAB M5 subtype and in 9 hyperleukocytic leukemias. However, the 3 acute promyelocytic leukemia (APL) with overt laboratory criteria of disseminated intravascular coagulation (DIC) had protein C concentration no lower than the remaining 2 patients with infectious DIC, which suggested the coagulopathy in APL might be due to mechanisms different from other forms of DIC.

scholarly journals Contribution of factor VIII light-chain residues 2007–2016 to an activated protein C-interactive site

2013 ◽  
Vol 109 (02) ◽  
pp. 187-198 ◽  
Author(s):  
Masahiro Takeyama ◽  
Hironao Wakabayashi ◽  
Philip Fay
Keyword(s):  
Light Chain ◽  
Protein C ◽  
Activated Protein C ◽  
Fluid Phase ◽  
Fold Increase ◽  
Binding Assays ◽  
Dot Blot ◽  
Binding Studies ◽  
Dot Blot Assay ◽  
Dot Blotting

SummaryAlthough factor (F) VIIIa is inactivated by activated protein C (APC) through cleavages in the FVIII heavy chain-derived A1 (Arg336) and A2 subunits (Arg562), the FVIII light chain (LC) contributes to catalysis by binding the enzyme. ELISA-based binding assays showed that FVIII and FVIII LC bound to immobilised active site-modified APC (DEGRAPC) (apparent K d ~270 nM and 1.0 μM, respectively). Fluid-phase binding studies using fluorescence indicated an estimated K d of ~590 nM for acrylodan-labelled LC binding to DEGR-APC. Furthermore, FVIII LC effectively competed with FVIIIa in blocking APC-catalysed cleavage at Arg336 (K i = 709 nM). A binding site previously identified near the C-terminal end of the A3 domain (residues 2007–2016) of FVIII LC was subjected to Ala-scanning mutagenesis. FXa generation assays and western and dot blotting were employed to assess the contribution of these residues to FVIIIa interactions with APC. Virtually all variants tested showed reductions in the rates of APC-catalysed inactivation of the cofactor and cleavage at the primary inactivation site (Arg336), with maximal reductions in inactivation rates (~3-fold relative to WT) and cleavage rates (~3 to ~9-fold relative to WT) observed for the Met2010Ala, Ser2011Ala, and Leu2013Ala variants. Titration of FVIIIa substrate concentration monitoring cleavage by a dot blot assay indicated that these variants also showed ~3-fold increases relative to WT while a double mutant (Met2010Ala/Ser2011Ala) showed a >4-fold increase in K m. These results show a contribution of a number of residues within the 2007–2016 sequence, and in particular residues Met2010, Ser2011, and Leu2013 to an APC-interactive site.

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