High impact information on DSPP

• Here we report the isolation and characterization of a third domain of DSPP, designated dentin glycoprotein (DGP) [1].
• Polyclonal antibodies were raised in chicken against recombinant pig DSP, and used to identify native DSP in fractions of tooth dentin proteins extracted from developing pig molars [2].
• DSP binds biotin-labeled hyaluronic acid, and such binding is inhibited by the addition of unlabeled hyaluronic acid [2].
• On SDS-PAGE and on urea gels, DSP appeared as a smear extending from 280 to 100 kDa, but in the presence of beta-mercaptoethanol the top of the DSP smear disappeared [2].
• Glycosaminoglycanases with assorted glycosaminoglycan (GAG) cleavage specificities coupled with Western analyses of the cleaved GAG "stubs" demonstrated that the DSP GAG attachments contain chondroitin 6-sulfate, but not keratan sulfate, heparan sulfate, chondroitin, or chondroitin 4-sulfate [2].

Biological context of DSPP

• The DSPP cDNAs contain open reading frames of 593 and 600 codons [3].
• We have constructed and screened a unidirectional cDNA library derived from the pulp organ of developing pig teeth, and isolated cDNA clones encoding DSP-only, as well as two DSPP clones with alternative sequences in their 3' coding regions [3].
• Cloning and characterization of reverse transcriptase polymerase chain reaction products confirmed the existence of mRNA encoding pDSP386, pDSPP593, and pDSPP600in vivo, but also suggested that DNA sequence redundancies in the DSPP coding region make it prone to cloning artifacts [3].
• Dentin sialoprotein (DSP) is a glycoprotein that is critical for proper tooth dentin formation, but little is known about the nature of its carbohydrate attachments and other post-translational modifications [2].
• Maximum activity was reached at pH 5.5 and 55 degrees C. DPP I shared some common substrate specificities, both on synthetic derivatives and on real peptides, with porcine muscle DPP III [4].

Anatomical context of DSPP

• When donors of the livers transplanted in "surviving pigs" (DSP) were compared with donors of the livers transplanted in "nonsurviving pigs" (DNSP), hepatic artery blood flow, portal blood flow, and pump blood flow were higher in the DSP [5].
• Dipeptidyl peptidase I (DPP I; EC 3.4.14.1) was purified from porcine skeletal muscle after several steps such as heat treatment, ammonium sulfate fractionation, gel filtration chromatography, and HPLC anion exchange chromatography [4].
• MAb 7G4 reactivity was tested against a primary culture of pig odontoblasts, revealing filaments specifically stained by the anti-DPP antibody [6].
• Acrosin, which is less soluble than DPP II, is released at a later time during the acrosome reaction [7].
• In fibroblasts, PEP had the highest activity, 12.28 +/- 4.00 nmole/min/mg protein (mean +/- SD), 45-fold higher than corresponding DPP II levels [8].

Associations of DSPP with chemical compounds

• Dentin glycoprotein: the protein in the middle of the dentin sialophosphoprotein chimera [1].
• DPP I was inhibited by the assayed cysteine peptidase inhibitors except p-CMB [4].
• These findings suggest that DPP II is a serine peptidase [9].
• Dentin phosphophoryn (DPP) was extracted after the mechanical dissociation of teeth and dialyzed against guanidine and EDTA solutions followed by CaC1(2) precipitation [6].
• The Km and V(max) values of DPP II at optimal pH (pH 6.0) were 1330 microM and 2.9 mumol/mg per min for Gly-Pro-MCA, and 360 microM and 1.43 mumol/mg per min for Lys-Ala-MCA, respectively [9].

Analytical, diagnostic and therapeutic context of DSPP

• Northern blots hybridized to radiolabeled DSP probes showed bands at 1.4, 2.5, 4.4, and 4.8 kb [3].
• Evidence for the lysosomal localization of DPP II included sedimentability and latency and its distribution, coincident with acid phosphatase, in two distinct isopycnic regions following equilibrium density centrifugation [10].
• At predefined time-points, ranging from 4 days to 12 weeks, experimental teeth were extracted and examined by use of light microscopy, and expression of dentin-related proteins in the pulps was investigated by immunohistochemistry, using antibodies against type I collagen, dentin sialoprotein (DSP), sheathlin, and EMD [11].
• Structural changes in the acrosome associated with DPP II release were detectable by electron microscopy but not by light microscopy [7].
• The effect of dentin phosphoprotein (DPP) over a wide concentration range on precipitation and crystallization of calcium phosphate was studied in supersaturated solutions at pH 7.8 and 25 degrees C with a gel matrix model [12].

References