Luna Izuhara    Department   School of Medicine, School of Medicine    Position   Assistant Professor
Article types	Original article
Language	English
Peer review	Peer reviewed
Title	DPP and DSP are Necessary for Maintaining TGF-β1 Activity in Dentin.
Journal	Formal name：Journal of dental research Abbreviation：J Dent Res ISSN code：(1544-0591)0022-0345(Linking)
Domestic / Foregin	Foregin
Volume, Issue, Page	93(7),pp.671-7
Author and coauthor	Yamakoshi Y, Kinoshita S, Izuhara L, Karakida T, Fukae M, Oida S
Publication date	2014/07
Summary	Porcine dentin sialophosphoprotein (DSPP) is the most abundant non-collagenous protein in dentin. It is processed by proteases into 3 independent proteins: dentin sialoprotein (DSP), dentin glycoprotein (DGP), and dentin phosphoprotein (DPP). We fractionated DPP and DSP along with TGF-β activity by ion exchange (IE) chromatography from developing pig molars and measured their alkaline phosphatase (ALP)-stimulating activity in human periodontal (HPDL) cells with or without TGF-β receptor inhibitor. We then purified TGF-β-unbound or -bound DPP and DSP by reverse-phase high-performance liquid chromatography (RP-HPLC) using the ALP-HPDL system. The TGF-β isoform bound to DPP and DSP was identified as being TGF-β1 by both ELISA and LC-MS/MS analysis. We incubated carrier-free human recombinant TGF-β1 (CF-hTGF-β1) with TGF-β-unbound DPP or DSP and characterized the binding on IE-HPLC using the ALP-HPDL system. When only CF-hTGF-β1 was incubated, approximately 3.6% of the ALP-stimulating activity remained. DPP and DSP rescued the loss of TGF-β1 activity. Approximately 19% and 10% of the ALP stimulating activities were retained by the binding of TGF-β to DPP and DSP, respectively. The type I collagen infrequently bound to CF-hTGF-β1. We conclude that both DPP and DSP help retain TGF-β1 activity in porcine dentin.
DOI	10.1177/0022034514534690
PMID	24799420