Soybean (Glycine max L.) Lipoxygenase 1 (LOX 1) Is Modulated by Nitric Oxide and Hydrogen Sulfide: An In Vitro Approach

Abstract

Hydrogen sulfide (H2S) and nitric oxide (NO) are two relevant signal molecules that can affect protein function throughout post-translational modifications (PTMs) such as persulfidation, S-nitrosation, metal-nitrosylation, and nitration. Lipoxygenases (LOXs) are a group of non-heme iron enzymes involved in a wide range of plant physiological functions including seed germination, plant growth and development, and fruit ripening and senescence. Likewise, LOXs are also involved in the mechanisms of response to diverse environmental stresses. Using purified soybean (Glycine max L.) lipoxygenase type 1 (LOX 1) and nitrosocysteine (CysNO) and sodium hydrosulfide (NaHS) as NO and H2S donors, respectively, the present study reveals that both compounds negatively affect LOX activity, suggesting that S-nitrosation and persulfidation are involved. Mass spectrometric analysis of nitrated soybean LOX 1 using a peroxynitrite (ONOO−) donor enabled us to identify that, among the thirty-five tyrosine residues present in this enzyme, only Y214 was exclusively nitrated by ONOO−. The nitration of Y214 seems to affect its interaction with W500, a residue involved in the substrate binding site. The analysis of the structure 3PZW demonstrates the existence of several tunnels that directly communicate the surface of the protein with different internal cysteines, thus making feasible their potential persulfidation, especially C429 and C127. On the other hand, the CysNO molecule, which is hydrophilic and bulkier than H2S, can somehow be accommodated throughout the tunnel until it reaches C127, thus facilitating its nitrosation. Overall, a large number of potential persulfidation targets and the ease by which H2S can reach them through the diffuse tunneling network could be behind their efficient inhibition.

Isoenzymatic Pattern of Hydrogen Sulfide (H2S)-Generating L-Cysteine Desulfhydrase (LCD) in Arabidopsis thaliana Seedlings: Effect of Nitric Oxide (NO) and H2S

“…In many cases, these molecules act via modulating the metabolism of reactive oxygen species (ROS) both in antioxidant systems and in ROSgenerating enzymes [2,27,41,42]. Regulation is usually performed through posttranslational modifications (PTMs) such as nitration, S-nitrosation, and persulfidation [28][29][30][31]43]. The best-known examples are the antioxidant enzymes that scavenge H 2 O 2, such as catalase and ascorbate peroxidase (APX).…”

“…Furthermore, it has been seen that both NO and H 2 S can regulate protein function through post-translational modifications such as nitration, S-nitrosation, and persulfidation. Thus, some enzymes such as catalase, lipoxygenase, NADP-dependent dehydrogenase, NADP malic enzyme, or peroxidase undergo modifications via both molecules affecting their functions either positively or negatively [27][28][29][30][31].…”

Persulfidome of Sweet Pepper Fruits during Ripening: The Case Study of Leucine Aminopeptidase That Is Positively Modulated by H2S

“…On the other hand, there is a group of enzymes whose activity has been observed to be downregulated by H 2 S, including glutamine synthetase (GS) [ 32 ] and 1-aminocyclopropane-1-carboxylic acid oxidase (ACO) in tomato [ 84 ], cysteine protease ATG4 [ 85 ], ATG18a [ 33 ], NADP-isocitrate dehydrogenase (NADP-ICDH) [ 86 ], NADP-malic enzyme (NADP-ME) [ 87 ], glucose-6-phosphate dehydrogenase (G6PDH) [ 29 ], catalase [ 88 ], flowering locus C protein (FLC1 and 3) [ 89 ], peroxidase IV [ 27 ], and lipoxygenase 1 (LOX 1) [ 90 ]. More recently, it has been shown that the persulfidation of cytosolic glucose 6-phosphate dehydrogenase in Arabidopsis and tomato can alter their homotetrameric structure and consequently the stability of the enzyme [ 91 ].…”

Phylogenetic Analysis and Lipoxygenase (LOX) Gene Family Variation in The Pistachio

“…These enzymes are also prevalent in the animal and plant kingdoms and play essential roles in resisting both biotic and abiotic stresses (Song et al, 2016). The biosynthesis of Lipoxygenases has been extensively studied in various plant species, including Arabidopsis thaliana (Melan et al, 1994), Triticum aestivum (Feng et al, 2012), Glycine max (González-Gordo et al, 2023), Arachis hypogaea (Mou et al, 2022) and Malus × domestica (Vogt et al, 2013). According to NCBI platform, 9 full length genes were recorded for Lipoxygenases (LOXs): 3 gene in Arabidopsis thaliana, 3 gene in Homo sapiens, 3 gene in Rattus norvegicus and one gene in Triticum aestivum .…”