Identification and measurement of d-glycero d-ido octulose 1,8-bisphosphate: D-altro-heptulose7-phosphotransferase enzyme in tissues with l-type pentose phosphate pathway activity

Arora, Krishan; Cortis, Philipa; Bleakley, Pamela; Williams, John F.

doi:10.1016/0020-711x(85)90056-4

Cited by 11 publications

(7 citation statements)

References 33 publications

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“…(6)) (Arora et al. 1985). \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {\sc D}\hbox{-}g\hbox{-}{\sc D}\hbox{-}i\hbox{-oct 8-P + Seh 1,7-P}_{2} \mathop{\longleftrightarrow}\limits^{\rm PT} {\sc D}\hbox{-}g\hbox{-}{\sc D}\hbox{-}i\hbox{-oct 1,8-P}_2 +\hbox{Seh 7-P} $$\end{document}…”

Section: Resultsmentioning

confidence: 99%

“…The presence and an excess of PT activity to support the maximum flux of Rib 5-P conversion to hexose and triose-P in vitro was reported for a number of animal and plant tissues (Arora et al. 1985). PT catalysed the reaction of Eq.…”

Section: Resultsmentioning

confidence: 99%

“…PT was also detected in French Press extracts of green algae ( Chlorella fusca ) and enzyme extracts of pea leaf (Arora et al. 1985) (see Table 4). The PT enzyme has not previously been investigated for any putative role in the metabolism of plants.…”

Section: Resultsmentioning

confidence: 99%

“…Rather the failure in the application of the oxidative-mode methods (Arora et al. 1985) is attributed inter alia to subversively high levels of Mg + and DTT in SEP.…”

Section: Resultsmentioning

confidence: 99%

“…(1985) published three assay procedures for the minimum estimate of the activity of d - glycero - d - ido -octulose 1,8-P 2 or d - glycero - d - altro -octulose 1,8-P 2 : d - altro -heptulose 7-phosphotransferase (PT). Two of these assays measured the reaction for the non-oxidative PP (Fig.…”

Section: Methodsmentioning

confidence: 99%

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The metabolic significance of octulose phosphates in the photosynthetic carbon reduction cycle in spinach

Williams

MacLeod

2006

Photosynth Res

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Abstract14 C-Labelled octulose phosphates were formed during photosynthetic 14 CO 2 fixation and were measured in spinach leaves and chloroplasts. Because mono-and bisphosphates of D-glycero-D-idooctulose are the active 8-carbon ketosugar intermediates of the L-type pentose pathway, it was proposed that they may also be reactants in a modified CalvinBenson-Bassham pathway reaction scheme. This investigation therefore initially focussed only on the ido-epimer of the octulose phosphates even though 14 C-labelled D-glycero-D-altro-octulose mono-and bisphosphates were also identified in chloroplasts and leaves.14 CO 2 predominantly labelled positions 5 and 6 of D-glycero-D-ido-octulose 1,8-P 2 consistent with labelling predictions of the modified scheme. The kinetics of 14 CO 2 incorporation into ido-octulose was similar to its incorporation into some traditional intermediates of the path of carbon, while subsequent exposure to 12 CO 2 rapidly displaced the 14 C isotope label from octulose with the same kinetics of label loss as some of the confirmed Calvin pathway intermediates. This is consistent with octulose phosphates having the role of cyclic intermediates rather than synthesized storage products. (Storage products don't rapidly exchange isotopically labelled carbons with unlabelled CO 2 .)A spinach chloroplast extract, designated stromal enzyme preparation (SEP), catalysed and was used to measure rates of CO 2 assimilation with Calvin cycle intermediates and octulose and arabinose phosphates. Only pentose (but not arabinose) phosphates and sedoheptulose 7-phosphate supported CO 2 fixation at rates in excess of 120 lmol h -1 mg -1 Chl. Rates for octulose, sedoheptulose and fructose bisphosphates, octulose, hexose and triose monophosphates were all notably less than the above rate and arabinose 5-phosphate was inactive. Altro-octulose phosphates were more active than phosphate esters of the ido-epimer. The modified scheme proposed a specific phosphotransferase and SEP unequivocally catalysed reversible phosphate transfer between sedoheptulose bisphosphate and D-glycero-Dido-octulose 8-phosphate. It was also initially hypothesized that arabinose 5-phosphate, an L-Type pentose pathway reactant, may have a role in a modified Calvin pathway. Arabinose 5-phosphate is present in spinach chloroplasts and leaves. Radiochromatography showed that 14 C-arabinose 5-phosphate with SEP, but only in the presence of an excess of unlabelled ribose 5-phosphate, lightly labelled ribulose 5-phosphate and more heavily labelled hexose and sedoheptulose mono-and bisphosphates. However, failure to demonstrate any CO 2 fixation by arabinose 5-phosphate as sole substrate suggested that the above labelling may have no metabolic significance. Despite this arabinose and ribose 5-phosphates are shown to exhibit active roles as enzyme co-factors in transaldolase and aldolase exchange reactions that catalyse the epimeric interconversions of the phosphate esters of ido-and altro-octulose. Arabinose 5-phosphate is presented as playing this role...

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

“…Rather the failure in the application of the oxidative-mode methods (Arora et al. 1985) is attributed inter alia to subversively high levels of Mg + and DTT in SEP.…”

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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The metabolic significance of octulose phosphates in the photosynthetic carbon reduction cycle in spinach

Williams

MacLeod

2006

Photosynth Res

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High yield synthesis of ¹⁴C labelled intermediates of the L‐type pentose pathway: Octulose mono‐ and bisphosphates, sedoheptulose 1,7‐bisphosphate and D‐arabinose 5‐phosphate

Arora

MacLeod

Williams

1987

Labelled Comp Radiopharmac

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i a m s D e p a r t m e n t o f B i o c h e m i s t r y , T h e F a c u l t i e s and R e s e a r c h S c h o o l o f C h e m i s t r y , The A u s t r a l i a n N a t i o n a l U n i v e r s i t y , GPO Box 4 , CANBERRA, ACT 2 6 0 1 A u s t r a l i a SUMMARY M e t h o d s f o r t h e n z y m i c s y n t h e s i s , i s o l a t i o n , p u r i f i c a t i o n c h a r a c t e r i s t i c o f t h e o c t u l o s e 8 -p h o s p h a t e and i t s a l t r o e p i m e r w e r e p r e p a r e d i n t r a n s k e t o l a s e c a t a l y z e d r e a c t i o n s i n vo 1 v i n g Bh y d r o x y p y r u v a t e and a p p r o p r i a t e 1 y 14C-1 a b e 1 1 ed a l d o h e x o s e 6 -p h o s p h a t e s . s y n t h e s i z e d by r e a c t i n g [ U -I 4 C ] g l u c o s a m i n e 6 -p h o s p h a t e w i t h n i n h y d r i n . p h o s p h a t e s was c o n f i r m e d u s i n g a v a r i e t y o f c h r o m a t o g r a p h i c m e t h o d s , e n z y m a t i c a n a l y t i c m e t h o d s and NMR s p e c t r o s c o p y . The I 4 C l a b e l l e d compounds a r e u s e d i n i n v e s t i g a t i o n s i n v o l v i n g t h e s e a r c h f o r t h e i d e n t i t y o f t h e p e n t o s e p a t h w a y i n t i s s u e s i n v i t r o , f o r t h e m e a s u r e m e n t o f L -t y p e p a t h w a y enzyme r e a c t i o n s and f o r t e s t i n g t h e m e c h a n i s t i c p r e d i c t i o n s o f t h e

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The pentose pathway: A random harvest

Williams

Arora

Longenecker

1987

International Journal of Biochemistry

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Identification and measurement of d-glycero d-ido octulose 1,8-bisphosphate: D-altro-heptulose7-phosphotransferase enzyme in tissues with l-type pentose phosphate pathway activity

Cited by 11 publications

References 33 publications

The metabolic significance of octulose phosphates in the photosynthetic carbon reduction cycle in spinach

The metabolic significance of octulose phosphates in the photosynthetic carbon reduction cycle in spinach

High yield synthesis of ¹⁴C labelled intermediates of the L‐type pentose pathway: Octulose mono‐ and bisphosphates, sedoheptulose 1,7‐bisphosphate and D‐arabinose 5‐phosphate

The pentose pathway: A random harvest

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Identification and measurement of d-glycero d-ido octulose 1,8-bisphosphate: D-altro-heptulose7-phosphotransferase enzyme in tissues with l-type pentose phosphate pathway activity

Cited by 11 publications

References 33 publications

The metabolic significance of octulose phosphates in the photosynthetic carbon reduction cycle in spinach

The metabolic significance of octulose phosphates in the photosynthetic carbon reduction cycle in spinach

High yield synthesis of 14C labelled intermediates of the L‐type pentose pathway: Octulose mono‐ and bisphosphates, sedoheptulose 1,7‐bisphosphate and D‐arabinose 5‐phosphate

The pentose pathway: A random harvest

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Product

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High yield synthesis of ¹⁴C labelled intermediates of the L‐type pentose pathway: Octulose mono‐ and bisphosphates, sedoheptulose 1,7‐bisphosphate and D‐arabinose 5‐phosphate