Light-harvesting complex II (LHCII) contains three highly homologous chlorophyll-a/b-binding proteins (Lhcb1, Lhcb2 and Lhcb3), which can be assembled into both homo- and heterotrimers. Lhcb1 and Lhcb2 are reversibly phosphorylated by the action of STN7 kinase and PPH1/TAP38 phosphatase in the so-called state-transition process. We have developed antibodies that are specific for the phosphorylated forms of Lhcb1 and Lhcb2. We found that Lhcb2 is more rapidly phosphorylated than Lhcb1: 10 sec of ‘state 2 light’ results in Lhcb2 phosphorylation to 30% of the maximum level. Phosphorylated and non-phosphorylated forms of the proteins showed no difference in electrophoretic mobility and dephosphorylation kinetics did not differ between the two proteins. In state 2, most of the phosphorylated forms of Lhcb1 and Lhcb2 were present in super- and mega-complexes that comprised both photosystem (PS)I and PSII, and the state 2-specific PSI–LHCII complex was highly enriched in the phosphorylated forms of Lhcb2. Our results imply distinct and specific roles for Lhcb1 and Lhcb2 in the regulation of photosynthetic light harvesting.

List of abbreviations: AChE = acetylcholinesterase; ADRs = adverse drug reactions; AZIN = azinphos-methyl; CE = carboxylesterases; Cli = intrinsic clearance; CPF = chlorpyrifos; CYP = cytochrome P450; DIA = diazinon; DIM = dimethoate; FEN = fenthion; FMO = fl avin-containing mono-oxigenase; IMI = imipramine; Iso-MAL = isomalathion; MAL = malathion; OP = organophosphorus compounds; OPT = organophosphorothionates; PAR = parathion; PON1 = oxonases.Abstract: Organophosphorothionates (OPT) are one of the most widely used insecticides in the world, both in agriculture and in indoor environment. Therefore, a large part of the population may be exposed to this class of pesticides, either professionally or due to their presence in food and water as residues. OPTs acute toxic effects, mediated by acetylcholinesterase (AChE) inhibition, are relatively selective to insects. However, most of the thousands of deaths annually reported to be associated to pesticide exposure are due to OPT severe poisoning, resulting in hyperexcitability of the nervous system. In addition, long-term neurological and neurobehavioral effects have been described, associated to chronic exposure to OPT low levels. Metabolism is one of the main factors determining OPT adverse effects. OPTs need to be bioactivated by a cytochrome P450 (CYP)-mediated desulfuration to phosphate triesters or oxons, which are the actual powerful inhibitors of brain and serum AChE. The main detoxifi cation pathways are oxon hydrolysis catalyzed by plasma oxonases (PON1), 'sequestration' or hydrolysis by carboxylesterases, CYP-catalyzed dearylation/dealkylation. Variation activity of the enzymes involved in OPT metabolism could be expected to contribute to differences in susceptibility to OPT toxic effects, either due to genetic polymorphism or environmental infl uence, altering the bioactivation/detoxication ratio. The reactions involved in OPT metabolism in humans are described in the paper, with consequences for OPT-induced toxicity. In addition, identifi cation of biomarkers of susceptibility and interactions among different OPTs and with other xenobiotics are briefl y discussed, as factors infl uencing risk assessment of cumulative effects due to OPT exposure.

Plant protease inhibitors (PIs) are generally small proteins present in high concentrations in storage tissues (tubers and seeds), and to a lower level in leaves. Even if most of them are active against serine and cysteine proteases, PIs active against aspartic proteases and carboxypeptidases have also been identified. Inhibitors of serine proteases are further classifiable in several families on the basis of their structural features. They comprise the families known as Bowman-Birk, Kunitz, Potato I and Potato II, which are the subject of review articles included in this special issue. In the present article we aim to give an overview of other families of plant PIs, active either against serine proteases or other class of proteases, describing their distribution, activity and main structural characteristics.

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Background According to the REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) restriction, tattoo and permanent make‐up (PMU) inks placed on the European Union market after January 4, 2022, shall not contain methylisothiazolinone, benzisothiazolinone (BIT), octylisothiazolinone (OIT), or other skin sensitizers in concentrations of 10 mg/kg or higher and phenoxyethanol (PE) or other eye irritants or damaging substances in concentrations of 100 mg/kg or higher. In addition, preservatives and other substances enlisted in Annex II to Cosmetic Product Regulation shall not be present in concentrations of 0.5 mg/kg or higher. Objectives This study aims to quantify 14 preservatives in 99 tattoo and 39 PMU inks from the Italian market and presents a comparison with concentration limits set by the REACH restriction. Methods Inks were analysed by applying validated analytical methods based on liquid chromatography techniques. Results About 24.0%, 15.2% and 1.5% of the overall samples contained BIT, PE and OIT, respectively, at concentrations exceeding REACH concentration limits. The number of noncompliant tattoo inks (49.5%) would be significantly greater than that of the PMU inks (17.9%). Conclusions About 40.6% of the samples would be noncompliant with the restriction for the presence of preservatives above the permitted level. Additional concentration limits will apply to skin sensitizing preservatives for proper labelling of inks under CLP (Classification, Labelling and Packaging) Regulation.

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