Use of 6-fluoroderivatives of pyridoxal and pyridoxal phosphate in the study of the coenzyme function in glycogen phosphorylase.

Chang, Yen Chung; Graves, Donald J.

doi:10.1016/s0021-9258(18)89419-4

Cited by 20 publications

(28 citation statements)

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“…This observation is consistent with the structures of these fluorinated compounds determined by NMR: In aqueous solutions, most 6-FPAL forms a hemiacetal, where the 4-, 5-, 5'-, and 4'-C's and 5'-0 form a closed five-member ring; this particular structure is absent in the remaining compounds (Chang et al, 1985). The rotation around the bond connecting the 5 and 5'-C's of the latter compounds can bring the 5'protons in close proximity to the 6-fluorine, whereas the ring structure of 6-FPAL hinders such a rotation.…”

Section: Resultssupporting

confidence: 88%

“…Low concentration of the hydrated form at pH 2 or lower prevented measurement of the second transition. The reaction mixture contains 50 mM glucose-l-P, 1 mM AMP, 40 mM /3-glycerophosphate, 2 mM EDTA, 5 mM DTE, 1% glycogen, 0.2 mg/mL apoenzyme or reconstituted enzyme, and varied concentrations of phosphite as indicated in the figure . pyridoxal (Chang et al, 1985). This result shows that the substitution of the 5'-phosphate group of 6-FDLP or the 5'-OH of 6-FPAL by a hydrogen does not affect the pvalues of other functional groups of the same molecule.…”

Section: Resultsmentioning

confidence: 75%

“…The purchase of [U-14C]glucose-l-P was from Amersham. Pyridoxine hydrochloride was purchased from National Biochemical Corp. Pyridoxal, pyridoxal phosphate, and glucose-1-P were obtained from Sigma Chemical Co. Synthesis of 6-fluoropyridoxal and 6-fluoropyridoxal phosphate and the reconstitution of apophosphorylase with these fluorinated analogues were reported earlier (Chang & Graves, 1985). 5'-Deoxypyridoxal (DPL) was kindly supplied by Dr.…”

Section: Methodsmentioning

confidence: 99%

“…These observations indeed provide information about the detailed pictures of phosphorylase-ligand complexes, but the high-resolution structure of the enzyme in the fully activated state, carrying out catalysis, has not been obtained. Recently, apophosphorylase reconstituted with 6-fluoropyridoxal (6-FPAL) or 6-fluoropyridoxal 5'-phosphate (6-FPLP) has been used as a model system to study the conformational changes of different protein-ligand complexes in solution (Chang et al, 1985). The results show that the binding of the substrate, glucose-1-P or phosphate, shifts the NMR signal of the protein-bound fluorine nucleus.…”

mentioning

confidence: 99%

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Function of pyridoxal 5'-phosphate in glycogen phosphorylase: a model study using 6-fluoro-5'-deoxypyridoxal- and 5'-deoxypyridoxal-reconstituted enzymes

Chang¹,

Scott²,

Graves³

1987

Biochemistry

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A new vitamin B6 analogue, 6-fluoro-5'-deoxypyridoxal (6-FDPL), was synthesized and characterized. This analogue, as well as 6-fluoropyridoxal (6-FPAL), 6-fluoropyridoxal phosphate (6-FPLP), and 6-fluoropyridoxine, showed positive heteronuclear 1H-19F nuclear Overhauser effects between the 5'-protons and the 6-fluorine. Apophosphorylase reconstituted with 6-FDPL showed 1% of the activity of the native enzyme in the presence of phosphite. The kinetic pattern, apparent pH optimum of activity, and the activity-temperature dependency of the 6-FDPL-enzyme were virtually identical with those of phosphorylase reconstituted with the parent compound, 6-FPAL [Chang, Y. C., & Graves, D. J. (1985) J. Biol. Chem. 260, 2709-2714], except the Km of phosphite toward the 6-FDPL-enzyme was 9 times higher than that with the 6-FPAL-enzyme and the 6-FDPL-enzyme showed a lower Vmax value. Phosphorylase reconstituted with 5'-deoxypyridoxal (DPL) also showed activity in the presence of phosphite. The kinetics and the temperature-activity dependency of this reconstituted enzyme were investigated. 19F nuclear magnetic resonance studies showed that the binding of glucose 1-phosphate to a 6-FDPL-enzyme-adenosine 5'-phosphate (AMP) complex shifted the 19F signal 0.6 ppm upfield, whereas a 2.1 ppm change was observed when the 6-FPAL-enzyme-AMP formed a complex with glucose 1-phosphate [Chang, Y. C., Scott, R. D., & Graves, D. J. (1986) Biochemistry 25, 1932-1939].(ABSTRACT TRUNCATED AT 250 WORDS)

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Section: Resultssupporting

confidence: 88%

Section: Resultsmentioning

confidence: 75%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

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Function of pyridoxal 5'-phosphate in glycogen phosphorylase: a model study using 6-fluoro-5'-deoxypyridoxal- and 5'-deoxypyridoxal-reconstituted enzymes

Chang¹,

Scott²,

Graves³

1987

Biochemistry

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“…There are also reports of proteins harboring pyridoxal‐groups as non‐natural cofactors. For example a 6‐fluoro pyridoxal phosphate bound to a phosphorylase leads to a lower activity of this enzyme compared to natural PLP, due to a lower basicity of the pyridine nitrogen [85] . Distefano and co‐workers attached a pyridoxal derivative (Figure 7, 8 ) to a suited cysteine (C117) in the adipocyte lipid binding protein via a disulfide bond [86] .…”

Section: Non‐natural Derivatives Of Natural Organocatalytic Cofactorsmentioning

confidence: 99%

Derivatives of Natural Organocatalytic Cofactors and Artificial Organocatalytic Cofactors as Catalysts in Enzymes

Lechner

Oberdorfer

2022

ChemBioChem

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Catalytically active non-metal cofactors in enzymes carry out a variety of different reactions. The efforts to develop derivatives of naturally occurring cofactors such as flavins or pyridoxal phosphate and the advances to design new, non-natural cofactors are reviewed here. We report the status quo for enzymes harboring organocatalysts as derivatives of natural cofactors or as artificial ones and their application in the asymmetric synthesis of various compounds.

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Functional Imaging Using Fluorine (19F) MR Methods: Basic Concepts

Waiczies

Prinz

Starke

et al. 2021

Methods in Molecular Biology

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Kidney-associated pathologies would greatly benefit from noninvasive and robust methods that can objectively quantify changes in renal function. In the past years there has been a growing incentive to develop new applications for fluorine (19F) MRI in biomedical research to study functional changes during disease states. 19F MRI represents an instrumental tool for the quantification of exogenous 19F substances in vivo. One of the major benefits of 19F MRI is that fluorine in its organic form is absent in eukaryotic cells. Therefore, the introduction of exogenous 19F signals in vivo will yield background-free images, thus providing highly selective detection with absolute specificity in vivo. Here we introduce the concept of 19F MRI, describe existing challenges, especially those pertaining to signal sensitivity, and give an overview of preclinical applications to illustrate the utility and applicability of this technique for measuring renal function in animal models.This chapter is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This introduction chapter is complemented by two separate chapters describing the experimental procedure and data analysis.

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Use of 6-fluoroderivatives of pyridoxal and pyridoxal phosphate in the study of the coenzyme function in glycogen phosphorylase.

Cited by 20 publications

References 28 publications

Function of pyridoxal 5'-phosphate in glycogen phosphorylase: a model study using 6-fluoro-5'-deoxypyridoxal- and 5'-deoxypyridoxal-reconstituted enzymes

Function of pyridoxal 5'-phosphate in glycogen phosphorylase: a model study using 6-fluoro-5'-deoxypyridoxal- and 5'-deoxypyridoxal-reconstituted enzymes

Derivatives of Natural Organocatalytic Cofactors and Artificial Organocatalytic Cofactors as Catalysts in Enzymes

Functional Imaging Using Fluorine (19F) MR Methods: Basic Concepts

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