Complement System

The complement system is part of the innate immune system and plays an important role in the host defense, inflammation, tissue regeneration and other physiological processes. Complement activation results in opsonization of pathogens and their removal by phagocytes. It also causes chemotactic attraction of phagocytes and macrophages. Furthermore, the complement system forms the terminal attack complex (MAC), a membrane channel causing osmotic lysis of the respective pathogen. While complement is not adaptable it does complement the adaptive immune system and it is also involved in B and T cell response regulation.

Activation of complement unfolds along three different complement activation pathways depending on the nature of the pathogen: the classical pathway, the lectin pathway, and the alternative pathway. All three converge into the common terminal pathway that leads to the formation of the MAC. In addition, anaphylatoxins C3a and C5a elicit a plethora of physiological responses that range from chemoattraction to apoptosis. The complement system consists of more than 30 proteins that are either present as soluble proteins in the blood or as membrane-associated proteins. Most exist as inactive zymogens that are then sequentially cleaved and activated. The central component in all three pathways is component C3, the most abundant complement protein found in the blood. Its activation induces the formation of the activation products C3a, C3b, and C5a and ultimately the MAC.

In addition to these three established pathways, it has been shown that factors such as kallikrein, plasmin, thrombin, and factor XIIa activate the complement system independently of the C3 protein.

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Classical Pathway

C1QA (Complement Component 1, Q Subcomponent, A Chain):

Western blot analysis of C1QA antibody (C-term) (ABIN391492) in Jurkat cell line lysates (35 µg/lane). C1QA (arrow) was detected using the purified polyclonal antibody.

This gene encodes a major constituent of the human complement subcomponent C1q. C1q associates with C1r and C1s in order to yield the first...

C1QA antibodies

C1QA ELISA Kits

C1QA Protein

C1QB (Complement Component 1, Q Subcomponent, B Chain):

Western blot analysis of C1QB Antibody (N-term) (ABIN652840) in Jurkat cell line lysates (35 µg/lane). C1QB (arrow) was detected using the purified polyclonal antibody.

This gene encodes a major constituent of the human complement subcomponent C1q. C1q associates with C1r and C1s in order to yield the first...

C1QB antibodies

C1QB ELISA Kits

C1QB Protein

C1QC (Complement Component 1, Q Subcomponent, C Chain):

C1QC Antibody (Center) (ABIN655873) flow cytometric analysis of HL-60 cells (right histogram) compared to a negative control cell (left histogram).FITC-conjugated goat-anti-rabbit secondary antibodies were used for the analysis.

This gene encodes a major constituent of the human complement subcomponent C1q. C1q associates with C1r and C1s in order to yield the first...

C1QC antibodies

C1QC ELISA Kits

C1QC Protein

C1R (Complement Component 1, R Subcomponent):

Human Tonsil: Formalin-Fixed, Paraffin-Embedded (FFPE)

WB Image Sample (30 ug of whole cell lysate) A: Molt-4 , 7.5% SDS PAGE antibody diluted at 1:1000

C1r B chain is a serine protease that combines with C1q and C1s to form C1, the first component of the classical pathway of the complement system.

C1R antibodies

C1R ELISA Kits

C1R Protein

Antigens in this category:

C1S (Complement Component 1, S Subcomponent):	C1S antibodies	C1S ELISA Kits	C1S Proteins
C4A (Complement Fragment 4a):	C4A antibodies	C4A ELISA Kits	C4A Proteins
C4 - Complement 4:	C4 antibodies	C4 ELISA Kits	C4 Proteins
C4B (Complement Component 4B):	C4B antibodies	C4B ELISA Kits	C4B Proteins

Lectin Pathway

MASP1 (Mannan-Binding Lectin serine Peptidase 1 (C4/C2 Activating Component of Ra-Reactive Factor)):

Formalin-fixed and paraffin embedded human lung carcinoma labeled with Anti- MASP Polyclonal Antibody, Unconjugated (ABIN733508) at 1:200, followed by conjugation to the secondary antibody and DAB staining.

This gene encodes a serine protease that functions as a component of the lectin pathway of complement activation. The complement pathway plays an essential role in the innate and adaptive immune response. The encoded protein is synthesized as a zymogen and is activated when it complexes with the pathogen recognition molecules of lectin pathway, the mannose-binding lectin and the ficolins. This... More...

Antigens in this category:

MBL2 (Mannose-Binding Lectin (Protein C) 2, Soluble):	MBL2 antibodies	MBL2 ELISA Kits	MBL2 Proteins
MASP2 (Mannan-Binding Lectin serine Peptidase 2):	MASP2 antibodies	MASP2 ELISA Kits	MASP2 Proteins
FCN1 (Ficolin (Collagen/fibrinogen Domain Containing) 1):	FCN1 antibodies	FCN1 ELISA Kits	FCN1 Proteins
FCN2 (Ficolin (Collagen/fibrinogen Domain Containing Lectin) 2 (Hucolin)):	FCN2 antibodies	FCN2 ELISA Kits	FCN2 Proteins
FCN3 (Ficolin (Collagen/fibrinogen Domain Containing) 3 (Hakata Antigen)):	FCN3 antibodies	FCN3 ELISA Kits	FCN3 Proteins

Alternative Pathway

CFB - Complement Factor B

Immunohistochemistry of paraffin-embedded mouse kidney using CFB antibody at dilution of 1:200 (x400 lens)

This gene encodes complement factor B, a component of the alternative pathway of complement activation. Factor B circulates in the blood as a...

CFB antibodies

CFB ELISA Kits

CFB Protein

CFD - Adipsin

CFD Antibody (N-term) western blot analysis in A549 cell line lysates (35ug/lane).This demonstrates the CFD antibody detected the CFD protein (arrow).

Western blot analysis of extracts of various cell lines, using CFD antibody.

Detection limit for recombinant GST tagged CFD is 0.03 ng/ml as a capture antibody.

The protein encoded by this gene is a member of the trypsin family of peptidases. The encoded protein is a component of the alternative complement...

CFD antibodies

CFD ELISA Kits

CFD Protein

Antigens in this category:

C3 (Complement Component 3):	C3 antibodies	C3 ELISA Kits	C3 Proteins
C3B - Complement Component C3b:	C3B antibodies
CFH - Complement Factor H:	CFH antibodies	CFH ELISA Kits	CFH Proteins

Terminal Pathway

C5 - Complement Component 5

Western blot analysis of C5 Antibody (N-term) (ABIN652518) in HL-60 cell line lysates (35 µg/lane). C5 (arrow) was detected using the purified polyclonal antibody.(2 µg/mL)

Formalin-fixed and paraffin embedded: Human laryngeal carcinoma labeled with Anti-C5a Polyclonal Antibody (ABIN727875), Unconjugated at 1:200, followed by conjugation to the secondary antibody was Goat Anti-Rabbit IgG, PE conjugated at 1:200 for 40 minutes at 37°C

Immunohistochemical analysis of Complement C5 staining in human stomach formalin fixed paraffin embedded tissue section. The section was pre-treated using heat mediated antigen retrieval with sodium citrate buffer (pH 6.0). The section was then incubated with the antibody at room temperature and detected using an HRP conjugated compact polymer system. DAB was used as the chromogen. The section was then counterstained with haematoxylin and mounted with DPX.

The protein encoded by this gene is the fifth component of complement, which plays an important role in inflammatory and cell killing processes. This protein is comprised of alpha and beta polypeptide chains that are linked by a disulfide bridge. An activation peptide, C5a, which is an anaphylatoxin that possesses potent spasmogenic and chemotactic activity, is derived from the alpha... More...

Antibodies

214 Products

ELISA Kits

83 Products

Proteins

23 Products

Antigens in this category:

C5a - C5A:	C5a antibodies	C5a ELISA Kits	C5a Proteins
C7 (Complement Component C7):	C7 antibodies	C7 ELISA Kits	C7 Proteins
C8A (Complement Component 8, alpha Polypeptide):	C8A antibodies	C8A ELISA Kits	C8A Proteins
C8B (Complement Component 8, beta Polypeptide):	C8B antibodies	C8B ELISA Kits	C8B Proteins
C8G (Complement Component 8, gamma Polypeptide):	C8G antibodies	C8G ELISA Kits	C8G Proteins
C9 (Complement Component C9):	C9 antibodies	C9 ELISA Kits	C9 Proteins

Regulators

CD55 (Complement Decay-Accelerating Factor):

Formalin-fixed and paraffin embedded human lung carcinoma labeled with Anti-CD55/DAF Polyclonal Antibody, Unconjugated at 1:200 followed by conjugation to the secondary antibody and DAB staining.

Immunofluorescence analysis of A549 cell using CD55 antibody. Blue: DAPI for nuclear staining.

Immunochemical staining of human CD55 in human lung with rabbit polyclonal antibody (1 µg/mL, formalin-fixed paraffin embedded sections).

This gene encodes a protein involved in the regulation of the complement cascade. The encoded glycoprotein is also known as the decay-accelerating...

CD55 antibodies

CD55 ELISA Kits

CD55 Protein

CD59 (CD59):

Western Blot analysis of CD59 expression in transfected 293T cell line by CD59 MaxPab polyclonal antibody. Lane 1: CD59 transfected lysate(14.20 KDa). Lane 2: Non-transfected lysate.

This gene encodes a cell surface glycoprotein that regulates complement-mediated cell lysis, and it is involved in lymphocyte signal transduction....

CD59 antibodies

CD59 ELISA Kits

CD59 Protein

Antigens in this category:

SERPING1 (Serpin Peptidase Inhibitor, Clade G (C1 Inhibitor), Member 1):	SERPING1 antibodies	SERPING1 ELISA Kits	SERPING1 Proteins
CFI - Complement Factor I:	CFI antibodies	CFI ELISA Kits	CFI Proteins
CR1 (Complement Component Receptor 1 (CD35)):	CR1 antibodies	CR1 ELISA Kits
CFP (Complement Factor P):	CFP antibodies	CFP ELISA Kits	CFP Proteins
C4BPA (Complement Component 4 Binding Protein, alpha):	C4BPA antibodies	C4BPA ELISA Kits	C4BPA Proteins
C4BPB (Complement Component 4 Binding Protein, beta):	C4BPB antibodies	C4BPB ELISA Kits	C4BPB Proteins

Extrinsic Pathway

F2 - Prothrombin

Western blot analysis of (1) Rat Serum and (2) Rat Liver Tissue.

Coagulation factor II is proteolytically cleaved to form thrombin in the first step of the coagulation cascade which ultimately results in the stemming of blood loss. F2 also plays a role in maintaining vascular integrity during development and postnatal life. Mutations in F2 leads to various forms of thrombosis and dysprothrombinemia. [provided by RefSeq, Jul 2008]. More...

Antibodies

282 Products

ELISA Kits

149 Products

Proteins

45 Products

Antigens in this category:

PLG (Plasminogen):	PLG antibodies	PLG ELISA Kits	PLG Proteins
KLK1 - Kallikrein 1:	KLK1 antibodies	KLK1 ELISA Kits	KLK1 Proteins
KLK2 - Kallikrein 2:	KLK2 antibodies	KLK2 ELISA Kits	KLK2 Proteins
PSA - Prostate Specific Antigen:	PSA antibodies	PSA ELISA Kits	PSA Proteins
KLKB1 (Kallikrein B, Plasma (Fletcher Factor) 1):	KLKB1 antibodies	KLKB1 ELISA Kits	KLKB1 Proteins
KLK4 - Kallikrein 4:	KLK4 antibodies	KLK4 ELISA Kits	KLK4 Proteins
KLK5 - Kallikrein 5:	KLK5 antibodies	KLK5 ELISA Kits	KLK5 Proteins
KLK6 - Kallikrein 6:	KLK6 antibodies	KLK6 ELISA Kits	KLK6 Proteins
KLK7 - Kallikrein 7:	KLK7 antibodies	KLK7 ELISA Kits	KLK7 Proteins
KLK8 - Kallikrein 8:	KLK8 antibodies	KLK8 ELISA Kits	KLK8 Proteins
KLK9 - Kallikrein 9:	KLK9 antibodies	KLK9 ELISA Kits	KLK9 Proteins
KLK10 - Kallikrein 10:	KLK10 antibodies	KLK10 ELISA Kits	KLK10 Proteins
PRSS57 (Protease, Serine, 57):	PRSS57 antibodies		PRSS57 Proteins
KLK11 - Kallikrein 11:	KLK11 antibodies	KLK11 ELISA Kits	KLK11 Proteins
KLK12 - Kallikrein 12:	KLK12 antibodies	KLK12 ELISA Kits	KLK12 Proteins
KLK13 - Kallikrein 13:	KLK13 antibodies	KLK13 ELISA Kits	KLK13 Proteins
KLK14 - Kallikrein 14:	KLK14 antibodies	KLK14 ELISA Kits	KLK14 Proteins
KLK15 - Kallikrein 15:	KLK15 antibodies	KLK15 ELISA Kits	KLK15 Proteins
F12 - Coagulation Factor XII (Hageman Factor):	F12 antibodies	F12 ELISA Kits	F12 Proteins

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