J O U R N A L O F WO U N D C A R E Vo l 2 2 . N o 1 . E W M A D o c u M E N t 2 0 1 3
origin
Enzyme
Source
Animal
Fibrinolysin
Bovineplasma
Desoxyribonuclease
Bovinespancreas
Krillmultienzymecomplex
Antarctickrill
Collagenase
Paralithodescamtschatica
Catalase
Equineliver
Plant
Papain
Caricapapaya
Bromelainenzymecomplex
Pineapple
Bacteria
Collagenase
Clostridium histolyticum
Streptokinase
Streptococcus haemolyticus
Streptodornase
Streptococcus haemolyticus
Sutilain
Bacillus subtilis
Table3.Proteolyticenzymesforwoundtreatment
34
Necrotic tissue consists of cellular debris embedded
in an extracellular matrix (ECM), mainly
consisting of type IV collagen, glycoproteins
and proteoglycans. These components are
released by the activity of collagenases and can
subsequently be degraded by macrophages and
other proteases. The resulting collagen fragments
stimulate additional fibroblasts and macrophages
and thus induce chemotactic effects. Collagen
also comprises 70–80% of the dry weight of the
skin and is the primary constituent of the human
dermis; therefore, it forms a substantial component
of the non-viable tissue.
In contrast to the collagenases of mammals, bacterial
collagenase breaks the triple helix structure of
various collagens at multiple points, thus generating
smaller peptides that induce forced further
degradation of the collagen. Bacterial collagenase
promotes wound healing by digesting native
collagen bundles that bind non-viable tissue to the
wound surface and by dissolving collagenic debris
within the wound. The most commonly used wound
products contain the collagenase Clostridiopeptidase
A from Clostridium histolyticum.
52–54
Streptokinase is a fibrin-degrading kinase
with a preferred point of attack between
arginine–valine bonds. The streptokinase catalyses
the generation of plasmin from plasminogen.
Plasmin degrades fibrin, fibrinogen, factor V
and VIII into polypeptides and amino acids. In
addition, plasmin forms a complex with human
plasminogen, leading to a conformational change
of plasminogen, exposing its active centre. The
result is a streptokinase-plasminogen complex
that can activate plasminogen. Therefore,
streptokinase’s effects require the presence of a
plasminogen-containing wound environment.
Streptodornase is a deoxyribonuclease
(DNAse) with endonucleolytic activity against
double-stranded DNA. Streptodornase will
contribute a complex with free plasminogen,
which catalyses the conversion of plasminogen
to plasmin. It liquefies the viscous nucleoprotein
of dead cells or pus and has no effect on living
cells. Similarly, coagulated blood can be liquefied
and then be absorbed. By these characteristics,
the streptodornase is particularly suitable when
used in combination with other enzymes, such as
|