In vitro degradation of human tropoelastin by MMP-12 and the generation of matrikines from domain 24.
Degradation of elastic fibers in tissues can result in the development of disorders that include aneurysms, atherosclerosis, and loss of skin elasticity. Tropoelastin is the precursor of the cross-linked elastin and its expression is triggered by elastin-degrading factors as a response to damage. Factors like UV radiation not only increase the expression of tropoelastin but also potent metalloelastases such as macrophage elastase (MMP-12). The development of elastin-degrading diseases, moreover, is a chronic process during which elastin and tropoelastin are repeatedly exposed to attacks by MMP-12. Hence, in this work we report the in vitro susceptibility of tropoelastin and the potential of MMP-12 to generate matrikines. This work provides evidence that tropoelastin is substantially and rapidly degraded by MMP-12 even at very dilute enzyme concentrations. MMP-12 cleaves at least 86 sites in tropoelastin. Analysis of the generated peptides revealed that some small peptides contained the motif GXXPG that may enable them to bind with the elastin binding protein (EBP). Furthermore, using synthesized peptides it was confirmed that several sites in the sequence encoded by exon 24 which contains repetitive units of biologically active VGVAPG domains are susceptible to attack by MMP-12, provided that the active subsites in MMP-12 (S(4) to S(4)') are occupied. Such cleavage events have lead to the generation of ligands that may bind to EBP.
Taddese
Samuel
S
Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.
Weiss
Anthony S
AS
Jahreis
Günther
G
Neubert
Reinhard H H
RH
Schmelzer
Christian E H
CE
D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D066298:In Vitro Techniques; D053508:Matrix Metalloproteinase 12 / Q000378:metabolism*; D008969:Molecular Sequence Data; D010455:Peptides / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary / Q000235:genetics*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D053719:Tandem Mass Spectrometry; D014333:Tropoelastin / Q000235:genetics / Q000378:metabolism*
D010455:Peptides; D014333:Tropoelastin; D053508:Matrix Metalloproteinase 12