Conformational transitions in glycogen phosphorylase reported by covalently bound pyridoxamine derivatives

Feldmann, Knut; Gaugler, Bernhard; Winkler, H.; Helmreich, Ernst

doi:10.1021/bi00707a031

Cited by 21 publications

(9 citation statements)

References 42 publications

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“…This suggestion has now been supported by a variety of studies carried out in several laboratories (Jones & Cowgill, 1971;Arrio-Dupont, 1971;Cortijoet al, 1971Cortijoet al, , 1976Forrey et al, 1971;Pfeuffer et al, 1972;Shaltiel et al, 1972;Veinberg et a]., 1974Veinberg et a]., , 1976Feldmann et al, 1974;Feldmann & Helmreich, 1976;Jimenez, 1976). On the other hand, the physiological substrates of the enzyme (glycogen, P,, glucose-1-P) are water soluble.…”

Section: Phosphorylase+mentioning

confidence: 82%

“…Structure A should have an absorption maximum at 45-41 5 nm by analogy to that reported for pyridoxal-5'-P Schiff bases in an aqueous environment (Metzler, 1957;Christensen, 1958;Shaltiel & Cortijo, I970 Feldmann & Helmreich, 1976). Structures Band C should have an absorption maximum at 288-297 nm by analogy to that of thiazolidine or hemimercaptal derivatives of pyridoxal-5'-P (respectively) when dissolved in organic solvents Shaltiel et al, 1972;Feldmann et al, 1974). Structures D-G should all have an absorption maximum at 325-335 nm as indicated in the text.…”

Section: Stoichiometric Binding Of Pyridoxal-5'-p To Mixed Micelles Omentioning

confidence: 98%

“…In recent years, physicochemical studies suggested that at neutral pH pyridoxal-5'-P is bound to phosphorylase through a Schiff base structure and is embedded in a hydrophobic microenvironment Johnson et al, 1970). This suggestion has now been supported by a variety of studies carried out in several laboratories (Jones & Cowgill, 1971;Arrio-Dupont, 1971;Cortijo et al, 1971Cortijo et al, , 1976Forrey et al, 1971;Pfeuffer et al, 1972;Shaltiel et al, 1972;Veinberg et al, 1974Veinberg et al, , 1976Feldmann et al, 1974;Feldmann & Helmreich, 1976;Jimenez, 1976). On the other hand, the physiological substrates of the enzyme (glycogen, Pi, glucose-1-P) are water soluble.…”

mentioning

confidence: 95%

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A micellar model for the pyridoxal 5'-phosphate site of glycogen phosphorylase

Gani¹,

Kupfer²,

Shaltiel³

1978

Biochemistry

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Mixed micelles composed of hexadecyltrimethylammonium bromide and dodecylamine hydrochloride were found to be good models for the site accommodating pyridoxal 5'-phosphate (pyridoxal-5'-P) in glycogen phosphorylase. At neutral pH, pyridoxal-5'-P becomes entrapped by such micelles (as shown by gel filtration) and reacts in stoichiometric ratios with the primary amine to yield a Schiff base derivative embedded in a hydrophobic microenvironment. The resulting pyridoxal-5'-P micelles simulate the enzyme in their absorption spectrum (maxima at 333 nm (major) and at -4 15 nm (minor)) and in their fluorescence characteristics (excitation maxima at 335 and -415 nm, emission maximum at -550 nm). These pyridoxal-5'-P micelles can be reduced with NaBH4 with concomitant disappearance of the 333-nm band to yield a product with an absorption maximum a t 288

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Section: Phosphorylase+mentioning

confidence: 82%

Section: Stoichiometric Binding Of Pyridoxal-5'-p To Mixed Micelles Omentioning

confidence: 98%

mentioning

confidence: 95%

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A micellar model for the pyridoxal 5'-phosphate site of glycogen phosphorylase

Gani¹,

Kupfer²,

Shaltiel³

1978

Biochemistry

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“…There are several lines of evidence pointing to the contribution of the pyridoxal 5'-phosphate site to the interprotomeric contact responsible for dimerization and induction of activity (q$ [18]). In accordance with this information apophosphorylase was incapable of inducing activity in homologous subunits and of forming half-active hybrids presumably because apo-holo-phosphorylase hybrids are not stable [1] Fig.…”

Section: The Role O J Pyridoxal 5'-phosphate In the Interactions O J mentioning

confidence: 99%

Complementation of Subunits from Glycogen Phosphorylases of Frog and Rabbit Skeletal Muscle and Rabbit Liver

Feldmann¹,

Zeisel²,

Helmreich³

1976

Eur J Biochem

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Activity can be induced in potentially active rabbit skeletal muscle phosphorylase monomers covalently bound to Sepharose by noncovalent interaction with soluble subunits carrying inactive pyridoxal 5'-phosphate analogs or even salicylaldehyde. These analogs are themselves incapable of reconstituting active holophosphorylase from apophosphorylase. Phosphorylases with one intrinsically inactive and one potentially active subunit have about one half of the activity of the native phosphorylase dimer.The usefulness of this technique for subunit complementation was demonstrated by forming hybrid phosphorylases with inactive Sepharose-bound rabbit skeletal muscle subunits containing pyridoxal 5'-phosphate monomethylester and soluble activatable frog muscle and rabbit liver phosphorylase monomers. The inactive Sepharose-bound subunit induced in each case activity in the soluble subunit. But whereas the inactive rabbit muscle phosphorylase subunit even transmitted its characteristic temperature dependence of the rate of the reaction to the frog muscle subunit, it could not propagate its control properties to the liver enzyme. Differences of hybrid phosphorylases are related to immunological and amino acid divergencies among the component enzymes.Complementation requires methods which preserve the structural integrity of the enzyme subunits and select for true hybrids over enzyme mixtures. We have used a technique for complementation of phosphorylase subunits which might be applicable generally. It was made possible because we had found previously that noncovalent interaction of Sepharosebound rabbit skeletal muscle glycogen phosphorylase monomers with subunits carrying inactive pyridoxal 5'-phosphate monomethylester yielded diniers with about one half of the activity of the native phosphorylase dimer [ 1 1. In this report we show the usefulness of this technique by the formation of stable hybrid phosphorylases made up of inactive Sepharose-bound rabbit skeletal muscle phosphorylase subunits containing pyridoxal 5'-phosphate monomethylester and soluble frog muscle and rabbit liver phosphorylase monomers. The phosphorylases used for hybridization have different regulatory and conformational properties and can be distinguished immunologically and with respect to their amino acid composition. The inactive Sepharose-bound subunit induced in each -~

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“…A direct involvement of the phosphate moiety of the coenzyme in catalysis has been demonstrated by means of a variety of analogue replacement studies (Kastenschmidt et al, 1968;Shaltiel et al, 1969;Pfeuffer et al, 1972;Feldmann et al, 1974;Vidgoff et al, 1974;Feldmann and Helmreich, 1976;Parrish et al, 1977;Shimomura and Fukui, 1978;Hoerl et al, 1979;Chang et al, 1983) and in more recent years by 31P NMR investigations (Feldmann and Hull, 1977;Withers et al, 1981a,b;Withers et al, 1982b). On the basis of such studies a variety of possible catalytic roles for the coenzyme phosphate have been proposed including potential involvement as an acid catalyst (Pfeuffer et al, 1972;Klein et al, 1982;Klein et al, 1984), a base catalyst (Helmreich and Klein, 1980), a nucleophile (Johnson et al, 1980), or an electrophile (Withers et al, 1981;Takagi et al, 1982;Tagaya and Fukui, 1984).…”

Section: Introductionmentioning

confidence: 99%

31P NMR relaxation studies of the activation of the coenzyme phosphate of glycogen phosphorylase. The role of motion of the bound phosphate

Withers¹,

Madsen²,

Sykes³

1985

Biophysical Journal

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Spin-lattice and spin-spin relaxation rates (1/T1 and 1/T2) have been determined for the catalytically essential coenzyme phosphate at the active site of glycogen phosphorylase in both activated (R state) and inactive (T state) conformations of the enzyme. Dipolar contributions to 31P relaxation due to exchangeable protons on the phosphate group have been determined by measurement of relaxation rates at different concentrations of H2O and D2O, and field dependence studies have been performed to estimate the contribution of chemical shift anisotropy to the remaining 31P relaxation in D2O. At 109 MHz, dipolar relaxation from exchangeable protons was found to account for 50% of the spin-lattice relaxation for activated phosphorylase in 75% H2O, the remainder being due to chemical shift anisotropy. The spin-lattice relaxation rates in D2O for R-state glycogen phosphorylase are very similar to those measured for other proteins of very different size such as actin (Brauer, M., and B. D. Sykes, 1981, Biochemistry. 20:6767-6775), alkaline phosphatase (Coleman, J. E., I. D. Armitage, J. F. Chlebowski, J. D. Otvos, and A. J. M. S. Uiterkamp, 1979), and phosphoglucomutase (Rhyu, G. I., W. J. Ray, Jr., and J. L. Markley, 1984, Biochemistry. 23:252-260). In inactive (T state) phosphorylase the spin-lattice relaxation rates were almost an order of magnitude slower, while the spin-spin relaxation rates were essentially identical. These results have been analyzed by calculating the theoretically expected 31P relaxation rates in the presence of internal motions that are included in the relaxation calculation using the model-free approach of Lipari and Szabo (1982, J. Am. Chem. Soc. 104:4564-4559). The analysis suggests the coenzyme phosphate is relatively immobilized in the activated enzymic conformation, but in the inactive (Tstate) conformation it is considerably more mobile with a rotational correlation time one to two orders of magnitude smaller. Since the spin-lattice relaxation rate for the active R-state (immobilized) phosphate is similar to that observed in other phosphoenzymes of different size it is suggested that a librational motion on the nanosecond time scale may constitute a common spin-lattice relaxation pathway for phosphates in macromolecules. The consequences of phosphate motion in terms of recent suggestions concerning the environment and the catalytic role of the coenzyme phosphate are discussed.

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Conformational transitions in glycogen phosphorylase reported by covalently bound pyridoxamine derivatives

Cited by 21 publications

References 42 publications

A micellar model for the pyridoxal 5'-phosphate site of glycogen phosphorylase

A micellar model for the pyridoxal 5'-phosphate site of glycogen phosphorylase

Complementation of Subunits from Glycogen Phosphorylases of Frog and Rabbit Skeletal Muscle and Rabbit Liver

31P NMR relaxation studies of the activation of the coenzyme phosphate of glycogen phosphorylase. The role of motion of the bound phosphate

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