On the interaction of soybean lipoxygenase‐1 and 13‐L‐hydroperoxylinoleic acid, involving yellow and purple coloured enzyme species

Groot, J.J.M.C. de; Garssen, G.J.; Veldink, Gerrit A.; Vliegenthart, J.F.G.; Boldingh, J.; Egmond, Maarten R.

doi:10.1016/0014-5793(75)80109-8

Cited by 92 publications

(51 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the present paper we shall demonstrate that this mechanism can also be used to explain the observations by De Groot et al (1975b). Weassess thecontributionofpre-steadystate redistributions of iron(I1) and iron(II1) lipoxygenase to the duration of the induction period, from dioxygenation curves recorded at a range of lipoxygenase concentrations.…”

Section: Mjs Is Supported By a Fellowship Under European Communitymentioning

confidence: 73%

“…However, initiation of the dioxygenation reaction with iron(II1) instead of iron(I1) lipoxygenase does not in general result in disappearance of the induction period. In some experiments (at 2.4 nM soybean lipoxygenase-1 and 0.24 or 0.48 mM linoleate) the progress curves of reactions initiated with iron(II1) lipoxygenase seemed to be identical to those of reactions initiated with iron(I1) lipoxygenase (De Groot et al, 1975b). When rapid kinetic techniques were used to study the initial stages of linoleate (23 or 86 pM) dioxygenation by 12 nM soybean lipoxygenase- 2 ) and E*-(02), iron(I1) and iron(II1) lipoxygenase, equilibrium complexes with 0 2 ; S, polyunsaturated fatty acid substrate; P, hydroperoxy fatty acid product; Sox and w, oxidized and reduced forms of S and P (radical compounds); K,, P,, K,, and P,, equilibrium dissociation constants of Es, E * S , E-P, and E*-P; Kay, equilibrium dissociation constant of the lipoxygenase-oxygen complexes; k, rate constants; k i = k2/(l + Koxy/[02]).…”

mentioning

confidence: 87%

See 1 more Smart Citation

Kinetic analysis of the induction period in lipoxygenase catalysis

Schilstra¹,

Veldink²,

Vliegenthart³

1993

Biochemistry

View full text Add to dashboard Cite

ABSTRACT:The dioxygenation of 50 pM linoleate at 0.1 pM (13s)-hydroperoxylinoleate, 240 pM 02, pH 10, and 25 O C , catalyzed by varying amounts of soybean lipoxygenase-1, was studied with rapid kinetic techniques. The aim was to assess the effect of transient redistributions of the Fe(I1) and Fe(II1) enzyme forms on the shape of the reaction progress curves. Reactions initiated with iron(I1) lipoxygenase show an initial increase in rate, the "kinetic lag phase" or "induction period". [Schilstra et al. (1992) Biochemistry 31,7692-76991 also shows an induction period whose duration is inversely proportional to [lipoxygenase]. These observations, in combination with nonsteady-state numerical simulations, lead to the conclusion that, at [lipoxygenase] < 2 nM, pre-steady-state redistributions of enzyme intermediates occur fast with respect to the rate at which the concentrations of substrates and products change. At higher lipoxygenase concentrations, the pre-steady-state redistributions contribute significantly to the induction period. From a nonlinear least-squares fit to the steady-state rate equation of data obtained at lipoxygenase concentrations of 0.5 and 1 nM, it was calculated that 1% of the linoleate radicals that are formed after hydrogen abstraction dissociate from the active site before enzymic oxygen insertion has occurred.Lipoxygenases (EC 1.13.1 1.12) catalyze dioxygenation of polyunsaturated fatty acids that contain one or more (12,42)-pentadiene systems. Their products are chiral (E,Z) conjugated hydroperoxy fatty acids (Veldink & Vliegenthart, 1984;Schewe et al., 1986;Kiihn et al., 1986a), which are the precursors of a number of physiological effectors in animal tissue (Parker, 1987) and possibly also in plants (Gardner, 1991).Lipoxygenase catalysis of polyunsaturated fatty acid dioxygenation exhibits a characteristic "induction period" (Haining & Axelrod, 1958) or "kinetic lag phase" (Smith & Lands, 1972): after the initiation of the reaction, the rate gradually increases until a maximum rate is reached. In this paper, we shall refer to the phase in which the rate increases as the induction period, irrespective of the cause of the acceleration. The induction period is eliminated when the product hydroperoxide (P) (Scheme I) is present in micromolar amounts at the start of the reaction (Haining & Axelrod, 1958;Schilstra et al., 1992). EPR studies on soybean lipoxygenase-1 demonstrated that P converts the iron cofactor of lipoxygenase from Fe(I1) into Fe(II1) (De Groot et al., 1975a;Slappendel et al., 1983). However, initiation of the dioxygenation reaction with iron(II1) instead of iron(I1) lipoxygenase does not in general result in disappearance of the induction period. In some experiments (at 2.4 nM soybean lipoxygenase-1 and 0.24 or 0.48 mM linoleate) the progress curves of reactions initiated with iron(II1) lipoxygenase seemed to be identical to those of reactions initiated with iron(I1) lipoxygenase (De Groot et al., 1975b). When rapid kinetic techniques were used to study the initial stage...

show abstract

Section: Mjs Is Supported By a Fellowship Under European Communitymentioning

confidence: 73%

mentioning

confidence: 87%

Kinetic analysis of the induction period in lipoxygenase catalysis

Schilstra¹,

Veldink²,

Vliegenthart³

1993

Biochemistry

View full text Add to dashboard Cite

show abstract

“…First, the autoactivation during the initial lag phase is described by an overall reaction of the ferrous enzyme (E) to the 'active' one (E*) which may consist of the oxidation of ferrous iron by the hydroperoxy fatty acid and a further activation step which is not yet elucidated. This assumption arises from the observation that the ferric (yellow) soybean lipoxygenase still exhibits an initial lag phase that can be abolished by addition of hydroperoxy fatty acid [20]. Moreover it is difficult to imagine that a simple ferric state should be sufficient to lower the energy barrier needed for the homolytic cleavage of a C-H bond leading to the fatty acid radical.…”

Section: Discussionmentioning

confidence: 99%

A kinetic model for lipoxygenases based on experimental data with the lipoxygenase of reticulocytes

Ludwig

Holzhütter

Colosimo³

et al. 1987

European Journal of Biochemistry

107

View full text Add to dashboard Cite

A comprehensive kinetic model for lipoxygenase catalysis is proposed which includes the simultaneous occurrence of dioxygenase and hydroperoxidase activities and is based on the assumption of a single binding site for substrate fatty acid and product.The aerobic reaction of purified lipoxygenase from rabbit reticulocytes with 9,12(Z,Z)-octadecadienoic acid (linoleic acid) as substrate was studied.The rate constants and the dissociation constants of this enzyme were calculated for the model from progress curves; the model describes correctly the experimental data.The following kinetic features of the reticulocyte enzyme are assumed to apply generally to lipoxygenases. As predicted from the model it was found that at low concentrations of oxygen the regio-and stereospecificities of the dioxygenation are diminished.During the autoactivation phase the steady-state approximation does not hold.Animal lipoxygenases (EC 1.1 3.1 1.12) have acquired particular interest owing to their key role in the biosynthesis of leukotrienes and other biologically active products of their action. So far research on their actions has been focussed on their positional and stereospecificity [l] ; mechanistic studies on their kinetics have hardly been performed. The situation is different with respect to plant enzymes, in particular soybean lipoxygenase, the kinetics of which has been studied extensively [2 -61. We undertook to set up a viable kinetic model for the reticulocyte lipoxygenase which may be considered to be a prototype of the animal lipoxygenases; this enzyme is available in purified form, sufficient amounts and has been the object of some mechanistic work by us [7]. In view of the many properties shared by plant and animal lipoxygenases we scrutinized the models proposed so far for the soybean enzyme as to their applicability to the reticulocyte enzyme and found them to be generally unsatisfactory in two respects.a is difficult to reconcile with the successful and well-tested onesite model for the anaerobic lipohydroperoxidase activity of soybean lipoxygenase [6]. A transition from a one-site catalysis under anaerobic conditions to a two-site catalysis under aerobic ones would imply either the existence of different active sites for hydroperoxidase and dioxygenase activity or the unmasking or forming of a second site by dioxygen.Therefore we tried to elaborate a one-site model which will describe both dioxygenase and concomitant hydroperoxidase activities of lipoxygenase using the kinetic model of Verhagen et al. [6] as starting point. This model and some of its predictions were tested on the reticulocyte lipoxygenase with 9,12(Z,Z)-octadecadienoic acid (linoleic acid) as substrate.The model elaborated is assumed to be applicable to study the kinetic behaviour of other lipoxygenases. MATERIALS AND METHODSLipoxygenase from reticulocytes was isolated and purified as described elsewhere [lo]. A peak fraction of the isoelectricfocussed enzyme was used with a specific activity of 8 s-and a protein content of 3.05mg/ml. Differen...

show abstract

“…In this activation process, as the proportion of ferric enzyme gradually increases, the rate of fatty acid oxygenation will also increase, manifesting itself in the progress curve of fatty acid oxygenation as a lag phase (11). A distinctive feature of LOX activation is that it is a single turnover event; once the enzyme is oxidized to the ferric form, it will no longer react with fatty acid hydroperoxides (12). Because of this single-turnover nature of the reaction, the products from LOX activation are formed in minute amounts and have not been identified.…”

Section: Lipoxygenases (Lox)mentioning

confidence: 99%

On the Role of Molecular Oxygen in Lipoxygenase Activation

Zheng

Brash

2010

Journal of Biological Chemistry

View full text Add to dashboard Cite

The oxygenation of polyunsaturated fatty acids by lipoxygenases (LOX) is associated with a lag phase during which the resting ferrous enzyme is converted to the active ferric form by reaction with fatty acid hydroperoxide. Epidermal lipoxygenase-3 (eLOX3) is atypical in displaying hydroperoxide isomerase activity with fatty acid hydroperoxides through cycling of the ferrous enzyme. Yet eLOX3 is capable of dioxygenase activity, albeit with a long lag phase and need for high concentrations of hydroperoxide activator. Here, we show that higher O 2 concentration shortens the lag phase in eLOX3, although it reduces the rate of hydroperoxide consumption, effects also associated with an A451G mutation known to affect the disposition of molecular oxygen in the LOX active site. These observations are consistent with a role of O 2 in interrupting hydroperoxide isomerase cycling. Activation of eLOX3, A451G eLOX3, and soybean LOX-1 with 13-hydroperoxy-linoleic acid forms oxygenated end products, which we identified as 9R-and 9S-hydroperoxy-12S,13S-trans-epoxyoctadec-10E-enoic acids. We deduce that activation partly depends on reaction of O 2 with the intermediate of hydroperoxide cleavage, the epoxyallylic radical, giving an epoxyallylic peroxyl radical that does not further react with Fe(III)-OH; instead, it dissociates and leaves the enzyme in the activated free ferric state. eLOX3 differs from soybean LOX-1 in more tightly binding the epoxyallylic radical and having limited access to O 2 within the active site, leading to a deficiency in activation and a dominant hydroperoxide isomerase activity.

show abstract

On the interaction of soybean lipoxygenase‐1 and 13‐L‐hydroperoxylinoleic acid, involving yellow and purple coloured enzyme species

Cited by 92 publications

References 9 publications

Kinetic analysis of the induction period in lipoxygenase catalysis

Kinetic analysis of the induction period in lipoxygenase catalysis

A kinetic model for lipoxygenases based on experimental data with the lipoxygenase of reticulocytes

On the Role of Molecular Oxygen in Lipoxygenase Activation

Contact Info

Product

Resources

About