HOMEPRODUCTSCOMPANYCONTACTFAQResearchDictionaryPharmaSign Up FREE or Login

Enhancement of drug delivery to bone: characterization of human tissue-nonspecific alkaline phosphatase tagged with an acidic oligopeptide.

Abstract
Hypophosphatasia is caused by deficiency of activity of the tissue-nonspecific alkaline phosphatase (TNSALP), resulting in a defect of bone mineralization. Enzyme replacement therapy (ERT) with partially purified plasma enzyme was attempted but with little clinical improvement. Attaining clinical effectiveness with ERT for hypophosphatasia may require delivering functional TNSALP enzyme to bone. We tagged the C-terminal-anchorless TNSALP enzyme with an acidic oligopeptide (a six or eight residue stretch of L-Asp), and compared the biochemical properties of the purified tagged and untagged enzymes derived from Chinese hamster ovary cell lines. The specific activities of the purified enzymes tagged with the acidic oligopeptide were the same as the untagged enzyme. In vitro affinity experiments showed the tagged enzymes had 30-fold higher affinity for hydroxyapatite than the untagged enzyme. Lectin affinity chromatography for carbohydrate structure showed little difference among the three enzymes. Biodistribution pattern from single infusion of the fluorescence-labeled enzymes into mice showed delayed clearance from the plasma up to 18 h post infusion and the amount of tagged enzyme retained in bone was 4-fold greater than that of the untagged enzyme. In vitro mineralization assays with the bone marrow from a hypophosphatasia patient using each of the three enzymes in the presence of high concentrations of pyrophosphate provided evidence of bone mineralization. These results show the anchorless enzymes tagged with an acidic oligopeptide are delivered efficiently to bone and function bioactively in bone mineralization, at least in vitro. They suggest potential advantages for use of these tagged enzymes in ERT for hypophosphatasia, which should be explored.
AuthorsTatsuo Nishioka, Shunji Tomatsu, Monica A Gutierrez, Ken-ichi Miyamoto, Georgeta G Trandafirescu, Patricia L C Lopez, Jeffrey H Grubb, Rie Kanai, Hironori Kobayashi, Seiji Yamaguchi, Gary S Gottesman, Richard Cahill, Akihiko Noguchi, William S Sly
JournalMolecular genetics and metabolism (Mol Genet Metab) Vol. 88 Issue 3 Pg. 244-55 (Jul 2006) ISSN: 1096-7192 [Print] United States
PMID16616566 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
Chemical References
  • Oligopeptides
  • Asparagine
  • Durapatite
  • Alkaline Phosphatase
Topics
  • Alkaline Phosphatase (chemistry, pharmacokinetics)
  • Animals
  • Asparagine (chemistry)
  • Bone Marrow Cells (drug effects, physiology)
  • Calcification, Physiologic (drug effects, physiology)
  • Cells, Cultured
  • Cricetinae
  • Cricetulus
  • Durapatite (chemistry)
  • Humans
  • Hypophosphatasia (pathology)
  • Infant
  • Liver (enzymology)
  • Mice
  • Oligopeptides (chemistry)
  • Tissue Distribution

Join CureHunter, for free Research Interface BASIC access!

Take advantage of free CureHunter research engine access to explore the best drug and treatment options for any disease. Find out why thousands of doctors, pharma researchers and patient activists around the world use CureHunter every day.
Realize the full power of the drug-disease research graph!


Choose Username:
Email:
Password:
Verify Password:
Enter Code Shown: