serum proteins

C1q

Binds to Fc region of IgM and IgG

C1r

Activates C1s

C1s

Cleaves C4 and C2

C4

Part of C3 convertase - C4b

C2

Binds to C4b - forms C3 convertase

C3

Key intermediate in all pathways

C5

Initiates membrane attack complex

C6

Binds to C5b in MAC

C7

Binds to C5bC6 in MAC

C8

Starts pore formation on membrane

C9

Polymerizes to cause cell lysis

C1,2,3,4,6,7

Proteins produced by monocytes and macrophage

C1 qrs

Serum proteins seen in intestinal epithelial cell

C2,3,4,5,6,7,8,9

Serum proteins seem in liver

Factor B

Binds to C3b to form C3 convertase

Factor D

Cleaves factor B

Properdin

Stabilizes C3bBb-C3 convertase

Mannan binding lectin

Binds to mannose

Mannan binding lectin associated serine proteases

Cleaves C4 and C2

C1 inhibitor

Dissociates C1r and C1s from C1q

Factor I

Cleaves C3B and C4B

factor H

Cofactor with I to inact C3b, prevents binding to B to C3b

C binding protein

Acts as cofactor with I to inact C4b

S protein or vitronectin

Prevents attachment of the C5b67 complex to cell membrane

105 204

88 35

150 300-450

520 250

84 500

Enumerate MW (KD) and Conc (mg/mL)

C1 inhibitor

Factor I

Factor H

C binding protein

S protein (vitronectin)

Lupuslike syndrome; recurrent infection

C1 (q,r,s) disease

Basophil and mast cell degranulation;

enhanced vascular permeability;

smooth muscle contraction

Functions of anaphylatoxin

C1r C1s

These are serine proteases

410, 000 D

MW of C1q

740,000 D

MW of C1 complex

70,000 D

MW of C2a

34,000 D

MW of C2b

190,000 D

MW of C3b and C5

110,000 D

MW of C6 and C7

150,000 D

MW of C8

70,000 D

MW of C9

C3

1mg/ml- 1.5 mg/ml

Major and pivotal component of all cascde with conc of —

C4

600 ug/Ml

2nd most abundant CP with serum conc of —

c5b

Powerful opsonin

15 sec to 3 mins

Half life of C3 convertase

60 microseconds

Half life of C3b

77 aa

AA of C4a

74 aa

AA of C5a

93,000D

MW of Factor B

33,000 D

60,000 D

MW of

Ba

Bb

24,000D

MW of Factor D

200 ug/ml

Serum conc of Factor B

2 ug/ml

Serum conc of Factor C

Lupuslike syndrome; recurrent infection;

Atherosclerosis

C2 dx

Severe recurrent infection; Glomerulonephritis

C3 dx

Lupuslike syndrome

C4 dx

Neisseria infections

C5-C8 dx

No known dx

C9 dx

Hereditarv angioedema

C1 INH dx

Paroxysmal nocturnal hemoglobinuria

Decay accelerating factor. (DAF)

Membrane inhibitor of rective lysis (MIRL) dx

Recurrent pyogenic infection

FACTOR H AND I dx

Pneumococcal diseases, Sepsis, Neisseria infection

Mannan binding lectin dx

Neisseria infx

Properdin dx

Pneumococcal disease

Mannan binding lectin associated with serine proteases dx