Enzyme Explorer

Plasmin

E.C. 3.4.21.7
Synonyms: fibrinase; fibrinolysin; actase; serum tryptase; thrombolysin

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Physical Properties and In vivo processing
Plasminogen:
Plasminogen is the precursor to the fibronolytic protease plasmin as well as angiostatin, an angiogenesis/tumor metastasis inhibitor. Human prostate carcinoma cells release urokinase and free sulfhydryl donors which can produce angiostatin from plasminogen. In vitro, urokinase, tissue plasminogen activator, or streptokinase, in combination with sulfydryl donors, such as N-acetyl-L-cysteine, D-penicillamine, captopril, L-cysteine, or reduced glutathione, produced angiostatin from plasminogen.1
Native-intact human plasminogen is a 291 amino acid glyco-protein with as many as 24 disulfide bonds. Plasminogen contains a single N-linked sialylated biantennary glycan. The two O-glycans possess a Gal β-1-3GalNAc core which is α-2-3 sialylated at the terminal Gal. An additional disialylated form has a second sialic acid residue with an α-2-6 linkage to GalNAc. Mono- and disialylated forms occur at a molar ratio of 80:20 in human plasminogen.2,3


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Plasmin:
MW: ~86 kDa4 (Human)
When run on SDS-PAGE, bands appeared at 68, 46.2, 23.1 and 12.3 kDa.

Plasmin is a serine endopeptidase of the peptidase S1 family. Plasmin is converted to plasminogen by cleavage between Arg561 and Val562. The resulting activated plasmin consists of two disulfide-linked polypeptide chains. The plasmin heavy chain (MW 60 kDa) is derived from the amino terminal region of plasminogen. The light chain originates from the carboxyl-terminus of plasminogen. In vivo, the MW of the heavy chain can vary from 63KDa to 12KDa depending on the extent of proteolysis to the plasminogen from which it is derived. Plasmin is activated by a variety of proteases including urokinase, tissue plasminogen activator, and streptokinase. During the activation of plasminogen, an autolytic peptide of molecular weight 8,200 is released from the Glu-amino terminus to yield a Lys-amino terminus on the heavy chain. The active site of plasmin is on the light chain.1

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Specificity and Kinetics
Plasmin exhibits preferential cleavage at the carboxyl side of Lysine and Arginine residues with higher selectivity than trypsin.5 It converts polymerized fibrin into soluble products.

pH Optimum: 8.5
pH 7.5: about 40% of maximal activity, pH 9.5: about 50% of maximal activity6

Temperature Optimum: 37 °C with rapid inactivation at 56 °C6


Inhibitors
Product #  Product Name Add to Cart
A1153 Aprotinin from bovine lung lyophilized powder, 3-8 TIU/mg solid
A2504 6-Aminocaproic acid ≥99% (titration), powder
A6191 Antipain dihydrochloride from microbial source
A2221 Antithrombin III from human plasma lyophilized powder, ≥95% (SDS-PAGE)
A7824 6-Aminocaproic acid SigmaUltra, ≥99%
A8456 4-(2-Aminoethyl)benzenesulfonyl fluoride hydrochloride ~97%
A9141 Antithrombin III from bovine plasma lyophilized powder, 200-400 units/mg protein (E1%/280 = 6.5)
B3906 Bdellin from leeches lyophilized powder, >0.1 IU/mg protein (E280)
C2412 C1 Esterase Inhibitor from human plasma aqueous solution, ≥90% (SDS-PAGE)
D0879 Diisopropyl fluorophosphate
D7910 3,4-Dichloroisocoumarin
E0518 C1 Esterase Inhibitor from human plasma aqueous solution, ≥95% (SDS-PAGE)
E0881 Elastatinal microbial, ~50%
G2417 Gabexate mesylate solid
L2023 Leupeptin trifluoroacetate salt ≥90% (HPLC), microbial
M6159 α2-Macroglobulin from human plasma lyophilized powder, ≥98% (SDS-PAGE)
P7626 Phenylmethanesulfonyl fluoride ≥98.5% (GC)
U4751 Urinary Trypsin Inhibitor Fragment ≥95% (HPLC)
A8849 α2-Antiplasmin from human plasma lyophilized powder, ≥5 inhibitor U/mg protein
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Substrates
Product #  Product Name Add to Cart
A8171 D-Ala-Leu-Lys-7-amido-4-methylcoumarin 95% (HPLC)
B1136 Boc-Val-Leu-Lys-7-amido-4-methylcoumarin
G8148 Gly-Arg-p-nitroanilide dihydrochloride
I6886 D-Ile-Phe-Lys p-nitroanilide ≥95% (HPLC)
51015 4-Nitrophenyl 4-guanidinobenzoate hydrochloride BioChemika, ≥95.0% (AT)
T6140 N-(p-Tosyl)-Gly-Pro-Lys 4-nitroanilide acetate salt
90170 Nα-p-Tosyl-L-arginine methyl ester hydrochloride BioChemika, for the determination of trypsin, ≥99.0% (AT)
V0882 D-Val-Leu-Lys 4-nitroanilide dihydrochloride
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Solubility and Solution Stability
Plasmin is readily soluble in water (1 mg/ml). Solutions should be kept on ice and discarded at the end of the day or aliquoted and frozen at a concentration of 1 mg/ml. Frozen solutions will lose approximately 10% activity per month.

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Products
Product #  Product Name Add to Cart
P9156 Plasminogen from bovine plasma lyophilized powder, 3-5 units/mg protein
P5661 Plasminogen from human plasma lyophilized powder, ≥2 units/mg protein, suitable for streptokinase determination by clot formation procedure
P7397 Plasminogen from human plasma lyophilized powder, ≥2 units/mg protein, not suitable for streptokinase determination by clot formation procedure
P1867 Plasmin from human plasma lyophilized powder, ≥3 units/mg protein
Related Products
Product #  Product Name Add to Cart
F5386 Fibrin from human plasma
S3134 Streptokinase from β-hemolytic Streptococcus (Lancefield Group C) lyophilized powder, ≥3,500 units/mg solid
S8026 Streptokinase from β-hemolytic Streptococcus (Lancefield Group C) buffered aqueous solution, ~100,000 units/mg protein
T5451 Tissue Plasminogen Activator from human melanoma cells vial of >5000 IU
U0633 Urokinase from human urine lyophilized powder, ≥500 units/mg protein
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References

  1. Gatley, S., et al., Proc. Natl. Acad. Sci. U S A, 94, 10868–10872 (1997)
  2. Marti, T., et al., Eur J Biochem., 173, 57-63 (1988)
  3. Pirie-Shepherd, S.R., et al., J Biol. Chem.,272, 7408-11 (1997)
  4. Trends Biochem. Sci., 4, 1 (1979)
  5. IUBMB Enzyme Nomenclature: www.chem.qmul.ac.uk/iubmb/enzyme/EC3/4/21/7.html
  6. Greig, B.H.W., et al., Biochim. Biophys. Acta, 67, 658-668 (1963)

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