The 3-hydroxy-3-methylglutaryl coenzyme-A reductases from fungi: a proposal as a therapeutic target and as a study model / La enzima 3-hidroxi-3-metilglutaril coenzima A reductasa de hongos: propuesta como diana terapéutica y como modelo de estudio

The enzyme 3-hydroxy-3-methylglutaryl coenzyme-A reductase (HMGR) catalyzes the conversion of HMG-Co-A into mevalonate. This step is the limiting point for the synthesis of cholesterol in mammals and ergosterol in fungi. We describe in this article the genome organization of HMGR coding genes and those deduced from different fungi, recount the evidence showing statins as HMGR inhibitors for ergosterol synthesis and its effect in yeast viability, and propose fungal HMGR (HMGRf) as a model to study the use of pharmaceutical compounds to inhibit cholesterol and ergosterol synthesis. Bibliographical search and bioinformatic analyses were performed and discussed. HMGRfs belong to the class I with a high homology in the catalytic region. The sterol biosynthetic pathway in humans and fungi share many enzymes in the initial steps (such as the HMGR enzyme), but in the last steps enzymes are different rendering the two final products: cholesterol in mammals and ergosterol in fungi. With regards to inhibitors such as statins and other compounds, these affect also fungal viability. Since HMGR from Schizosaccharomyces pombe and Ustilago maydis are very similar to the human HMGR in the catalytic regions, we propose that fungal enzymes can be used to test inhibitors for a potential use in humans. We consider that HMGRf is a good therapeutic target to design and test new antifungal compounds. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012) (AU)

La enzima 3-hidroxi-3-metilglutaril coenzima A reductasa (HMGR) cataliza la conversión de HMG-Co-A a mevalonato, paso limitante en la síntesis de colesterol en mamíferos y de ergosterol en hongos. El presente artículo describe la organización de genes codificantes y proteínas de las diferentes HMGR de hongos (HMGRf), expone las evidencias disponibles en la inhibición de HMGR en la síntesis de ergosterol y su efecto en la viabilidad de los hongos, y propone las HMGRf como modelo de estudio para la aplicación de fármacos inhibidores de las síntesis de colesterol y ergosterol. Para ello se realizó una búsqueda bibliográfica y análisis bioinformáticos, con descripción de los datos. Las HMGRf son de clase i y presentan una alta homología en la región catalítica. La vía biosintética de esteroles en el ser humano y en los hongos comparte algunas enzimas iniciales (como la HMGR) pero, en los últimos pasos, las enzimas son diferentes, lo que genera productos finales distintos: colesterol y ergosterol, respectivamente. La inhibición de HMGRf por estatinas afecta a la síntesis de ergosterol y la viabilidad. Dado que el sitio catalítico de las HMGR de Schizosaccharomyces pombe y Ustilago maydis es muy similar al de la enzima humana, podrían servir como modelos para el estudio de fármacos inhibidores de la síntesis de colesterol. La HMGRf es una diana terapéutica adecuada para el diseño de nuevos antimicóticos.Este artículo forma parte de una serie de estudios presentados en el «V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi» (Oaxaca, México, 2012)(AU)

Coenzyme A contained in mothers' milk is associated with the potential to induce atopic dermatitis.

T(h)2 adjuvant activity can be qualitatively and quantitatively evaluated using a mixed lymphocyte reaction and by changes in the intracellular cyclic adenosine 3',5'-monophosphate concentration, using human dendritic cells in vitro. The current study shows that mothers, whose children (n = 55) developed atopic dermatitis (AD) within 6 months after birth, often demonstrate a higher T(h)2 adjuvant activity in their milk, in comparison to those whose children did not develop such symptoms. Such an activity was recovered in a liquid phase of mothers' milk and was eluted as a single fraction by reversed-phase HPLC. Further analysis of this fraction by mass spectrometry showed that signals originating from a factor with a molecular weight of 767.53 are observed, exclusively in milk with a high T(h)2 adjuvant activity. The mass is exactly that of Coenzyme A (CoA), and indeed, a low concentration of CoA exhibited T(h)2 adjuvant activity both in vitro and in vivo. Moreover, mesenteric lymph node non-T cells obtained from mice that were orally treated with CoA led allogeneic naive CD4(+) T cells to differentiate into T(h)2. Furthermore, the oral administration of CoA induced rough skin, hyperplasia of the epidermis, hypergranulosis in the spinous layer and the thickening of the stratum in mice. These data collectively indicate that some of the patients with AD were exposed to mothers' milk carrying high T(h)2 adjuvant activity right after birth, which may be attributable to presence of CoA contained in the milk.

Nucleotide cofactor-binding-domain-specific antibodies show immunologic relatedness among unrelated proteins that bind phosphoryl compounds.

The immunologic relatedness of various cofactor-binding sites of enzymes requiring different nucleotide cofactors was examined. Chicken antibodies specific for NADPH- or CoA-binding domains were raised using an NADPH- or CoA-requiring enzyme as an immunogen. Antibodies specific for either NADPH- or CoA-binding domains were isolated by immunoaffinity chromatography of the respective antisera using unrelated NADPH- or CoA-requiring enzymes as affinity ligands. The reactivities of the NADPH- and CoA-binding-site-specific antibodies with a variety of enzymes that required different cofactors was shown on Western blots of SDS-PAGE of the enzymes. Variable cross-reactivities were observed among all nucleotide-cofactor requiring enzymes with each specific cofactor-domain-antibody population. Numerous proteins not physiologically associated with nucleotide cofactors, including acyl carrier protein, were completely unreactive. Proteins that bound phosphoryl compounds either as substrates or cofactors showed varying degrees of reactivity with each population of specific antibodies. These included aldolase, ribulose-1,5-bisphosphate carboxylase/oxygenase, ribonuclease A, carbonic anhydrase and triosephosphate isomerase. The immunologic cross-reactivity suggested that these proteins share a common structural feature, probably a primary structure epitope, since the proteins had been subjected to denaturing polyacrylamide gel electrophoresis. A candidate for this common structural feature is a glycine-rich sequence comprising a phosphate binding loop.