Objective: Enamelysin (MMP20) and kallikrein 4 (KLK4) are believed to be necessary to clear proteins from the enamel matrix of developing teeth. MMP20 is expressed by secretory stage ameloblasts, while KLK4 is expressed from the transition stage throughout the maturation stage. The aim of this study is to investigate the activation of KLK4 by MMP20 and the inactivation of MMP20 by KLK4.
Design: Native pig MMP20 (pMMP20) and KLK4 (pKLK4) were isolated directly from enamel scrapings from developing molars. Recombinant human proKLK4 (rh-proKLK4) was activated by incubation with pMMP20 or recombinant human MMP20 (rhMMP20), and the resulting KLK4 activity was detected by zymography. Reaction products were isolated by reverse-phase high performance liquid chromatography (RP-HPLC), and their N-termini characterized by Edman degradation. The pMMP20 was incubated with pKLK4 under mildly acidic or under physiologic conditions, and enzyme activity was analyzed by zymography. The catalytic domain of rhMMP20 was incubated with pKLK4 or recombinant human KLK4 (rhKLK4) and the digestion products were characterized by zymography and Edman degradation.
Results: Both pMMP20 and rhMMP20 activated rh-proKLK4 by cleaving at the propeptide-enzyme junction used in vivo. The pMMP20 was inactivated by pKLK4 under physiologic conditions, but not under mildly acidic conditions. Both pKLK4 and rhKLK4 cleaved MMP20 principally at two sites in the catalytic domain of MMP20.
Conclusions: MMP20 activates proKLK4 and KLK4 inactivates MMP20 in vitro, and these actions are likely to occur during enamel formation in vivo.
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http://dx.doi.org/10.1016/j.archoralbio.2013.08.005 | DOI Listing |
Cytotechnology
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Department of Genetics, Osmania University, Hyderabad, Telangana State India.
Targeting tumor angiogenesis with safe endogenous protein inhibitors is a promising therapeutic approach despite the plethora of the first line of emerging chemotherapeutic drugs. The extracellular matrix network in the blood vessel basement membrane and growth factors released from endothelial and tumor cells promote the neovascularization which supports the tumor growth. Contrastingly, small cleaved cryptic fragments of the C-terminal non collagenous domains of the same basement membrane display antiangiogenic effect.
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College of Food Science and Technology, Jiangsu Agri-animal Husbandry Vocational College Taizhou 225300 China
Bacterial infections are a major global health challenge, posing severe risks to human well-being. Although numerous strategies have been developed to combat bacterial pathogens, their practical application is often hindered by operational constraints. Photocatalytic materials have emerged as promising candidates for bacterial disinfection and food preservation due to their efficiency and sustainability.
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Reproductive Medicine, Torch Clinic, Tokyo, JPN.
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Institute of Biochemical Sciences, National Taiwan University, Taipei, 10617, Taiwan.
Background: Rho GTPases are essential regulators for cellular movement and intracellular membrane trafficking. Their enzymatic activities fluctuate between active GTP-bound and inactive GDP-bound states regulated by GTPase activating proteins (GAPs) and guanine nucleotide exchange factors (GEFs). Arhgap39/Vilse/Porf-2 is a newly identified GAP.
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