Stereospecificity of inositol hexakisphosphate dephosphorylation by Paramecium phytase.

InsP6 is an abundant compound in many micro-organisms, plants and animal cells. Its function and route of synthesis are still largely unknown. Degradation of InsP6 is mediated by phytase, which in most organisms dephosphorylates InsP6 in a relatively non-specific way. In the micro-organism Parameciu...

ver descrição completa

Na minha lista:
Detalhes bibliográficos
Main Authors: Van der Kaay, J, Van Haastert, P J
Formato: Artigo
Idioma:English
Publicado em: 1995
Assuntos:
Research Article
Acesso em linha:https://ncbi.nlm.nih.gov/pmc/articles/PMC1136199/
https://ncbi.nlm.nih.gov/pubmed/8554537
Tags: Adicionar Tag
Sem tags, seja o primeiro a adicionar uma tag!
id pubmed-1136199
record_format dspace
spelling pubmed-11361992005-09-07 Stereospecificity of inositol hexakisphosphate dephosphorylation by Paramecium phytase. Van der Kaay, J Van Haastert, P J Biochem J Research Article InsP6 is an abundant compound in many micro-organisms, plants and animal cells. Its function and route of synthesis are still largely unknown. Degradation of InsP6 is mediated by phytase, which in most organisms dephosphorylates InsP6 in a relatively non-specific way. In the micro-organism Paramecium, however, the enzyme has been shown to dephosphorylate InsP6 to InsP2 in a specific order, but its stereospecificity has not been established, i.e. the phosphates are removed in the sequence 6/5/4/3 or 6/5/4/1 or 4/5/6/1 or 4/5/6/3 [Freund, Mayr, Tietz and Schultz (1992) Eur. J. Biochem. 207, 359-367]. We have isolated the InsP4 intermediate and identified its absolute configuration as D-Ins(1,2,3,4)P4. Furthermore, degradation of [3,5-32P]InsP6 yielded a 32P-labelled InsP2 isomer, D-Ins(2,3)P2. These data demonstrate that Paramecium phytase removes the phosphates of InsP6 in the sequence 6/5/4/1. Knowing the stereochemical course of the enzyme, it can be used to elucidate the route of InsP6 synthesis, as it allows us to determine the specific radioactivity at individual positions of the molecular after pulse-labelling cells with [32P]P1 in vivo or [gamma-32P]ATP in vitro. 1995-12-15 /pmc/articles/PMC1136199/ /pubmed/8554537 Text en
institution US National Library of Medicine
collection PubMed Central
language English
format Article
topic Research Article
spellingShingle Research Article
Van der Kaay, J
Van Haastert, P J
Stereospecificity of inositol hexakisphosphate dephosphorylation by Paramecium phytase.
description InsP6 is an abundant compound in many micro-organisms, plants and animal cells. Its function and route of synthesis are still largely unknown. Degradation of InsP6 is mediated by phytase, which in most organisms dephosphorylates InsP6 in a relatively non-specific way. In the micro-organism Paramecium, however, the enzyme has been shown to dephosphorylate InsP6 to InsP2 in a specific order, but its stereospecificity has not been established, i.e. the phosphates are removed in the sequence 6/5/4/3 or 6/5/4/1 or 4/5/6/1 or 4/5/6/3 [Freund, Mayr, Tietz and Schultz (1992) Eur. J. Biochem. 207, 359-367]. We have isolated the InsP4 intermediate and identified its absolute configuration as D-Ins(1,2,3,4)P4. Furthermore, degradation of [3,5-32P]InsP6 yielded a 32P-labelled InsP2 isomer, D-Ins(2,3)P2. These data demonstrate that Paramecium phytase removes the phosphates of InsP6 in the sequence 6/5/4/1. Knowing the stereochemical course of the enzyme, it can be used to elucidate the route of InsP6 synthesis, as it allows us to determine the specific radioactivity at individual positions of the molecular after pulse-labelling cells with [32P]P1 in vivo or [gamma-32P]ATP in vitro.
author Van der Kaay, J
Van Haastert, P J
author_facet Van der Kaay, J
Van Haastert, P J
author_sort Van der Kaay, J
title Stereospecificity of inositol hexakisphosphate dephosphorylation by Paramecium phytase.
title_short Stereospecificity of inositol hexakisphosphate dephosphorylation by Paramecium phytase.
title_full Stereospecificity of inositol hexakisphosphate dephosphorylation by Paramecium phytase.
title_fullStr Stereospecificity of inositol hexakisphosphate dephosphorylation by Paramecium phytase.
title_full_unstemmed Stereospecificity of inositol hexakisphosphate dephosphorylation by Paramecium phytase.
title_sort stereospecificity of inositol hexakisphosphate dephosphorylation by paramecium phytase.
publishDate 1995
url https://ncbi.nlm.nih.gov/pmc/articles/PMC1136199/
https://ncbi.nlm.nih.gov/pubmed/8554537
_version_ 1760270514696224768