La dystrophine est une très grande protéine codée le gène DMD et située sous la membrane plasmique des fibres musculaires. Elle joue un rôle essentiel dans le maintien de l’intégrité de la cellule musculaire lors des cycles de contraction/relaxation. Cette protéine filamenteuse est composée de quatre domaines structuraux dont le domaine central composé de 24 répétitions homologues à la spectrine. Chaque répétition est organisée en faisceau de trois α-hélices appelé « coiled-coil ». Des mutations du gène DMD sont à l’origine des myopathies de Duchenne (DMD) et de Becker (BMD) qui s’accompagnent d’un déficit total ou d’une dystrophine mutée et induisent de ruptures fréquentes de la membrane des cellules musculaires. La connaissance de la structure de la dystrophine est nécessaire au développement de thérapies à ce jour inexistantes pour les myopathies. Au laboratoire, des données structurales du domaine central de la dystrophine ont été acquises par diffusion des rayons X aux petits angles (SAXS, Small Angles X-ray Scattering). Cette thèse présente le développement d’une approche multi-échelle combinant des données expérimentales SAXS et des données in silico pour la reconstruction de modèles haute-résolution des fragments du domaine central de la dystrophine et d’un fragment muté observé dans une mutation BMD fréquente. Nous avons également cartographié l’interaction de ce domaine central avec deux de ses partenaires fonctionnels importants, l’actine filamenteuse et avec la nitroxyde synthase neuronale (nNOS) et proposé les premiers modèles atomiques des complexes macromoléculaires correspondants. L’ensemble de ces résultats permettra à terme l’optimisation de thérapies pour le traitement des dystrophies musculaires. / Dystrophin is a large protein encoded by DMD gene and located under the plasma membrane of muscle fibers. It plays an essential role in maintaining the integrity of muscle cells during contraction/relaxation cycles. This filamentous protein is composed of four structural domains including the central domain consisting of 24 spectrin-like repeats and four hinges. Each repetition is folded in three α-helices in a ‘coiled-coil’ assembly. Mutations in the DMD gene leads to Duchenne muscular dystrophy (DMD) and Becker (MDBs), which are accompanied by frequent plasma membrane ruptures, due to the loss or modification of dystrophin protein. There are very few structural data available concerning the central domain of dystrophin, which is subject to many mutations involved in DMD and BMD diseases. However, the description and the understanding to an atomic level of dystrophin structure and its interaction is essential for optimization of therapies. Given the impossibility to solve its structure by X-ray crystallography or NMR, structural data of the dystrophin central domain were acquired by small angles X-rays scattering (SAXS, Small Angles X-ray Scattering). This thesis presents the development of an innovative multi-scale approach combining experimental SAXS and in silico derived data, allowing the reconstruction of high-resolution models of dystrophin central domain fragments. Structural data were also obtained on a mutated dystrophin frequently observed in BMDs. Furthermore, we also mapped the interactions of the central domain with two of its majors functional partners, Filamentous actin and neuronal nitroxyde synthase (nNOS) and proposed models of the related macromolecular complexes. At long-term, all of these results will allow optimization of therapies for the treatment of muscular dystrophies.

Orientadores: Watson Loh, Edvaldo Sabadini / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-24T08:19:42Z (GMT). No. of bitstreams: 1 Padula_Lilian_D.pdf: 2979563 bytes, checksum: 326395f8133ab39db6f41ffbeff5d688 (MD5) Previous issue date: 2013 / Resumo: Esta tese envolve o estudo da origem da alta viscosidade de dois óleos pesados brasileiros, OF1 e OF2, utilizando, para isso, aditivos químicos e tratamentos físicos. Através deste estudo confirmou-se o papel importante dos asfaltenos na viscosidade dos óleos aqui estudados. Investigações com espalhamento de raios-X em baixo ângulo (SAXS) indicaram a presença de agregados nestes óleosos quais apresentam uma agregação sequencial e hierarquizada. Além disso, estudou-se o que exercia um papel mais marcante sobre a viscosidade, o tamanho dos agregados ou a concentração dos mesmos. Verificou-se então que a concentração de agregados é o que apresenta maior efeito sobre a viscosidade dos óleos, uma vez que óleos com diferentes viscosidades 300.000 e 30.000 mPas apresentaram tamanho de agregados muito próximos,maior que 41 e 43 nm. No entanto, asconcentrações de asfalteno C5I eram bem diferentes para OF2s e OF1s, 14 e 20 % respectivamente, sendo mais viscosos aqueles com maior concentração de asfaltenos. O estudo com aditivos de diferentes classes mostrou que os mesmos não promoviam redução da viscosidade superior a 40 %. Além disso, mesmo os aditivos que causaram redução de 40 % na viscosidade não demonstraram nenhum efeito na microestrutura dos óleosquando avaliados por SAXS. Devido a esses resultados, propôs-se um modelobaseado no modelo desuspensão coloidal no qual os aditivos atuam sobre a fase contínua, em um efeito similar ao de diluição, não promovendo alterações nos agregados de asfaltenos na faixa de concentração estudada. Portanto, não faria sentido pensar em aditivos que em pequenas concentrações reduzam drasticamente a viscosidade / Abstract: Investigation of the elevated viscosity of two Brazilian heavy oils, OF1 and OF2, using several classes of additives and physical treatments. The studyreinforced the asphaltenes role on heavy oils viscosity. And SAXS investigationshave shown the presence of aggregates in these oils which aggregates in asequential and hierarchized. Furthermore showed also that, the concentration has a major contribution than the size of aggregates, because crudes with very different viscosities 300.000 and 30.000 mPas presented very similar aggregates sizes, 41 and 43 nm, but concentrations of asphaltene I5 quite different 14 and 20% respectively. Studying the rheology of several classes of additives the maximum viscosity reduction promoted was 40% of the initial value for heavy oils OF1s and OF2s presented. Also, the additives did not promote changes on the microstructure of asphaltene aggregates; therefore, a hypothesis having in mind petroleum as a colloidal suspension was formulated. This hypothesis states that the additives act only on the continuous medium, not on the aggregates themselves, similarly to a dilution effect. Therefore, it is very unlikely to find an additive that can be used as viscosity reducer through asphaltene disaggregation on heavy oils, at least on the additive concentration range studied here / Doutorado / Físico-Química / Doutora em Ciências

La dystrophine est une grande protéine membranaire périphérique qui assure un rôle de soutien du sarcolemme permettant aux cellules musculaires de résister aux stress mécaniques engendrés lors des processus de contraction/élongation. Des mutations génétiques conduisent à sa production sous forme tronquée voire à un déficit total en protéine engendrant de sévères myopathies actuellement incurables. Concevoir des thérapies adaptées passe par une meilleure compréhension du rôle biologique de la dystrophine. Par une approche structure/fonction, notre objectif est de déterminer les bases moléculaires impliquées dans les interactions de la dystrophine avec les lipides membranaires du sarcolemme. Grâce à une approche de diffusion aux petits angles (SAXS et SANS) combinée à de la modélisation moléculaire, nous montrons dans un premier temps que les bicelles constituent un modèle expérimental particulièrement adapté aux analyses de structures de protéines qui y sont associées. Ce développement méthodologique original a été exploité dans un deuxième temps pour caractériser les modifications structurales subies par la dystrophine lorsqu’elle interagit avec les lipides. Nous montrons particulièrement que la liaison aux lipides induit l’ouverture significative de la structure en triple hélice « coiled-coil » de la répétiton 1 du domaine central, et proposons en conclusion un modèle tout atome de la protéine en présence de bicelles. Ces travaux de thèse (i) constituent un apport méthodologique significatif pour l’étude de protéines membranaires, (ii) contribuent à une meilleure compréhension du rôle biologique de la dystrophine en vue de thérapies dédiées aux patients atteints de myopathies. / Dystrophin is a large peripheral membrane protein that provides a supporting role for sarcolemma allowing muscle cells to withstand the mechanical stresses generated during contraction / elongation processes. Genetic mutations lead to dystrophin production in truncated form or even to a total deficit in the protein leading to severe myopathies currently incurable. Designing adapted therapies requires a huge knowledge of the biological role of dystrophin. Using a structure / function approach, our aim is to determine the molecular bases involved in the interactions of dystrophin with the membrane lipids of the sarcolemma. Using a small-angle scattering approach (SAXS and SANS) combined with molecular modeling, we show that bicelles constitute a versatile membrane mimic that is particularly adapted to analyze the structure of membrane proteins. This original methodological development was exploited to characterize the structural changes undergone by dystrophin upon lipid binding. We highlight in particular that the lipid binding induces a significant opening of the coiled-coil structure of the repeat 1 of the central domain and, in conclusion, we propose an all-atom model of the protein bound to a bicelle. These thesis works (i) constitute a significant methodological contribution for the study of membrane proteins, (ii) contribute to a better understanding of the biological role of dystrophin for therapies dedicated to patients with myopathies.

Xanthomonas citri (X. citri), causador do cancro cítrico, afeta muitas áreas de cultivo de citros com impacto comercial. Transportadores ABC foram relatados como essenciais para a patogênese de X. citri. O gene nrtT codifica a proteína periplasmática responsável pelo suposto transporte de nitrato/nitrito/taurina. Neste trabalho, mostramos que a deleção de nrtT não afeta o crescimento de X. citri, porém reduz e atrasa os sintomas do cancro durante a infecção em folhas de citros. Observamos redução na produção de goma xantana e capacidade de aderência na linhagem mutante. A proteína NrtT foi expressa monomérica e monodispersa. Foram observadas alterações na estrutura secundária e aumento da estabilidade térmica de NrtT na presença de MOPS, indicando ser este um possível ligante de NrtT. A proteína PotF descrita como ligadora de putrescina não sofre alteração significativa na estabilidade térmica na presença de putrescina, entretanto, dados de SAXS mostram alterações na estrutura possivelmente decorrentes da ligação com putrescina. / Xanthomonas citri (X. citri), which causes citrus canker, affects many citrus growing areas with commercial impact. ABC transporters have been reported as essential for the pathogenesis of X. citri. The nrtT gene encodes the periplasmic protein responsible for the alleged transport of nitrate/nitrite/taurine. In this work, we show that nrtT deletion does not affect the growth of X. citri, but delays and reduces the symptoms of cancer during infection of citrus leaves. We observed a reduction in the production of xanthan gum and adhesion capacity in the mutant strain. The NrtT protein was expressed monomeric and monodisperse. There were changes in the secondary structure and increased thermal stability NrtT in the presence of MOPS, indicating that this was a possible binder NrtT. The PotF protein described as putrescine-binding is not significantly altered thermal stability in the presence of putrescine, however, SAXS data shows changes in the structure possibly resulting from connection with putrescine.

L’information génétique contenue dans le noyau de la cellule doit être dupliquée fidèlement afin d’être transmise aux cellules filles pendant la division cellulaire. Pour organiser leur division, les cellules suivent un cycle reproductible composé de quatre étapes appelé cycle cellulaire. La préparation et l’exécution du programme de réplication de l’ADN ont lieu pendant des phases spécifiques du cycle grâce à l’intervention de multiples partenaires protéiques et de régulateurs structuraux. En particulier, la réplication de l’ADN s’effectue sur une matrice complexe constituée d’ADN associé à des protéines appelée chromatine. Cette dernière influence et est influencée par la réplication de l’ADN. Le travail présenté ici a pour objectif de faire le lien entre la conformation de la chromatine et la cinétique de réplication de l’ADN. Pour ce faire, nous combinons plusieurs techniques. La cytométrie de flux nous permet de suivre la quantité d’ADN présent dans une population de cellules et, à l’aide d’une méthode développée dans notre laboratoire, d’extraire le programme de réplication moyen d’une population de cellules. La technique de SAXS fournit des informations sur l’organisation locale des protéines et de l’ADN in vivo. Nos données peuvent être interprétées comme un cristal liquide avec un ordre nématique et une faible longueur de corrélation, ce qui suggère que la chromatine de la levure est majoritairement dépourvue d’une organisation en fibre de 30nm in vivo. Par ailleurs, par la méthode de peignage d’ADN, nous reproduisons les résultats précédemment obtenus montrant que la distance entre zones répliquées est d’environ ~60kb qui correspond à la distance entre des origines de réplication identifiées. Cependant, d’après l’étude du comportement dynamique de l’initiation, nous proposons que les initiations sont plus fréquentes que ce qui a été mesuré précédemment et correspondent à la distance entre les protéines MCM disposées sur le génome. / Genetic information carried in the cell nucleus must be faithfully duplicated to be transmitted to daughter cells during cell division. In order to orchestrate their division, cells go through a reproducible 4 stages cycle called «cell cycle». The preparation and execution of the DNA replication program is restricted to specific phases and implies many proteic and structural regulators. In particular, DNA replication occurs on a complex template of DNA associated with proteins. The latter is both influencing and influenced by DNA replication. This work aims at investigating the link between chromatin conformation and the kinetics of DNA replication. In order to do so, we combine several techniques. Using flow cytometry, we follow the evolution of a cell population with regards to their DNA content and, with a method developed in our laboratory, decipher the population averaged temporal program of DNA replication. SAXS data provide information on the local organisation of protein and DNA in vivo. Our data can be interpreted as a liquid crystal with a nematic order and a short correlation length, which suggest that yeast chromatin in vivo is predominantly devoid of 30 nm fibres organisation. On the other hand, we performed DNA combing to study the replication program in single cells. We reproduce previously obtained result showing that distance between replicated tracks is of ~60kb which corresponds to the distance between known origins of replication. However, studying the behaviour of initiation, we propose that the initiation events are more frequent than previously measured and correspond to distances between MCMs proteins loaded on the genome.

L’auto-assemblage de particules virales est un sujet de recherche qui suscite beaucoup d’intérêt dans le cadre de la physique de la matière molle, les mécanismes physiques d’auto-assemblage étant encore très mal compris. En particulier, le chemin cinétique à partir duquel les protéines virales interagissent avec le génome pour former des structures symétriques et monodisperses que sont les virus ne sont pas entièrement résolus. Dans une première partie de cette thèse, nous utilisons la technique de diffusion des rayons X aux petits angles résolue en temps (Time-Resolved Small-Angle X-Ray Scattering, TR-SAXS en anglais) pour observer les cinétiques d’auto-assemblage et de désassemblage de capsides vides formées à partir des protéines du virus de la marbrure chlorotique de la cornille (CCMV en anglais). Des modèles de cinétique chimique couplés à des concepts théorique de diffusion aux petits angles sont conçus pour extraire les intermédiaires de réaction, leur structure et leur temps de vie caractéristique. L’encapsulation d’ARN simple brin avec les protéines virales du CCMV est également étudiée dans cette thèse. A un pH neutre où les protéines ne s’assemblent pas spontanément pour former des capsides vides, des images de microscopie électronique montrent qu’il y a une population de complexes nucléoprotéiques désordonnés qui coexistent avec des capsides virales bien formées. De plus, les données de cinétique de TR-SAXS suggèrent que l’assemblage protéine-acide nucléique subit une réorganisation structurale dans laquelle les protéines rendent le complexe nucléoprotéique plus compact lorsqu’elles s’attachent à l’ARN. En milieu acide, les objets sont plus ordonnés, comme le suggère les images de microscopie électronique. Ces observations suggèrent que l’encapsulation d’ARN et la formation de virus avec leur haut degré de symétrie est probablement un assemblage à deux étapes, la première étant la formation du complexe nucléoprotéique et la deuxième l’acidification du milieu. / Viral assembly is an intriguing topic of biophysics that can be studied using concepts of soft matter physics. Although huge efforts have been made to synthesize hybrid or non-hybrid supramolecular assemblies with viral proteins, the fundamental mechanisms of self-assembly are yet poorly understood. In particular, the kinetic pathway in which the proteins interact with the genome to form highly symmetrical monodisperse architectures are not completely solved.In the first part of this thesis, the Time-Resolved Small-Angle X-Ray Scattering (TR-SAXS) technique is used to probe the kinetics of both self-assembly and disassembly of empty capsids built up from the proteins of the Cowpea Chlorotic Mottle Virus (CCMV). Chemical kinetics models coupled with concepts of SAXS theory are devised in order to extract information about the nature of the reaction intermediates, their structure and their typical lifetime. The encapsulation of ssRNA with CCMV capsid proteins is also examined in this thesis. At neutral pH where the capsid proteins do not spontaneously assemble in vitro into empty spherical capsids, electron microscopy images show that there is a non-negligible population of disordered nucleoprotein complexes that coexist with well-formed spherical viruses. Additionally, TR-SAXS kinetic data suggest that the protein-nucleic acid assembly undergoes a structural reorganization in which the capsid proteins make the nucleoprotein complexes more compact as they simultaneously bind the RNA. Upon acidification, the particles are well-formed viruses as suggested by electron microscopy images. These findings suggest that the encapsulation of RNA into well-formed viruses is likely a two-step assembly with a binding step and an acidification step.

Pendant les dernières décennies les chercheurs ont étudié l'interaction entre des inclusions membranaires avec leur environnement et plus particulièrement avec la bicouche lipidique. On trouve dans la litérature beaucoup d'études théoriques et de simulations numériques sur ce sujet mais très peu d'expériences ont été menés là-dessus.Nous avons effectué des études systématiques afin de quantifier le potentiel d'interaction entre deux types d'inclusions au sein de la même couche et entre des couches adjacentes de plusieurs types de membranes ceci en variant surtout la concentration de particules dopantes, mais aussi d'autres paramètres pertinents : le type de tensioactif, l'épaisseur de la membrane, le contenu en cholestérol, la température, le degré d'hydratation. Pour cette fin nous avons utilisé la diffraction des rayons X aux petits angles et nous avons constaté que le potentiel d'interaction peut être décrit par une exponentielle décroissante en fonction de la concentration et de la température d'inclusion et qu'il dépend largement de la teneur en cholestérol et du degré d'hydratation.D'autre part, nous avons étudié l'effet de la gramicidine, un peptitde membranaire, sur l'ordre local des chaînes acyles de lipides et de tensioactifs. Cette étude a été menée en utilisant deux techniques différentes: en premier lieu la résonnance magnétique nucléaire, (DROSS-NMR) qui permet de détecter le changement d'ordre dans l'orientation des chaînes acyles, et en second lieu par diffraction des rayons X aux grands angles afin de déterminer le changement d'ordre dans la position des chaînes acyles. Nous avons trouvé que le dopage de la gramicidine dans les membranes rigidifie les chaînes acyles et dans un cas aussi les têtes polaires et en plus induit une modification de l'ordre local de ces chaînes. / For years scientists have been studying the interaction of membrane inclusions with their environment and more particularly with the lipid bilayer.This field has been based on theoretical approaches and numerical simulation and lack experiments.We performed systematic studies in order to quantify the interaction potential between two types of inclusions within the same layer and between adjacent layers in several kinds of membranes and tried to elucidate the influence of the relevant parameters: the type of lipids or surfactants, the cholesterol content, the hydration degree, the type of inclusions and the membrane thickness using small-angle X-ray scattering. We found that the interaction potential can be described by a decreasing exponential as a function of inclusion concentrations and temperature and depends largely on the cholesterol content and hydration degree.On the other hand, we also studied the effect of the peptide inclusions on the local order of lipid and surfactant acyl chains using two different techniques: DROSS-NMR technique to detect the changes in the orientational order and WAXS technique to detect the changes in the positional order of the acyl chains. We found that inserting these peptides inclusions within the membrane rigidifies the acyl chains and sometimes even the headgroups and modifies their local order.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23895号 / 工博第4982号 / 新制||工||1778(附属図書館) / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 奥田 浩司, 教授 安田 秀幸, 教授 辻 伸泰 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

[pt] A estearamidopropil dimetilamina (SAPDMA) é um surfactante presente em diversos cosméticos do mercado, principalmente em condicionadores e máscaras capilares. Devido ao seu caráter pseudo-catiônico, essa amidoamina alquílica neutraliza as cargas negativas presentes no cabelo, diminuindo o frizz e deixando-os macios e fáceis de pentear. Além disso, essa molécula é uma ótima substituta aos catiônicos tradicionais, por apresentar menor toxicidade aquática e maior biodegradabilidade. Porém, a SAPDMA é uma molécula não-iônica e insolúvel em água pura, tornando-se positivamente carregada apenas quando em menores valores de pH. Atualmente, sabe-se que diferentes ácidos podem originar formulações com diferentes propriedades físico-químicas, porém este fenômeno ainda não é totalmente compreendido. Este trabalho visa avaliar sistemas com 8 ácidos diferentes, e compreender como essa escolha tem impacto nas estruturas coloidais formadas pelo surfactante. Além disso, também tem como objetivo entender como a presença de álcool graxo influencia na formação da fase líquido-cristalina lamelar, alterando as propriedades finais desses diferentes sistemas. As técnicas de caracterização adotadas neste estudo foram a microscopia óptica convencional e de polarização, o espalhamento de luz dinâmico (DLS), o espalhamento de raios X a baixos ângulos (SAXS) e a reologia. Os resultados mostram o impacto da escolha dos ácidos nas estruturas coloidais, implicando diferenças que não dependem exclusivamente da variação de pH, mas também das diferentes interações entre a SAPDMA e os ânions envolvidos. A tendência do sistema é formar a fase líquido-cristalina lamelar, mas dependendo do ácido utilizado, as lamelas podem apresentar diferentes morfologias, com alterações em sua curvatura. Dessa forma, a escolha do ácido pode impactar na formação, ou não, de vesículas, além de ter enorme papel na estabilidade dos sistemas e nas propriedades sensoriais dos produtos, as quais são fundamentais para atender as necessidades dos consumidores. Sabe-se que, por um lado, as bicamadas fornecem maior viscosidade para o sistema do que as vesículas, sendo essa uma propriedade de enorme importância para aplicação em cosméticos. Porém, por outro lado, as bicamadas mais maleáveis, as quais podem se fechar mais facilmente formando as vesículas, são uma melhor opção em sistemas de emulsões, já que conseguem estabilizar melhor as gotas de óleo dispersas. Este estudo mostra a importância de se compreender melhor esses sistemas e o impacto do ácido utilizado, para que melhores formulações possam ser elaboradas pelas indústrias de cosméticos, que já fazem uso desse surfactante em diversos produtos consumidos pela sociedade. Segundo o nosso colaborador direto, Dr. Heitor de Oliveira (Coty Inc., Darmstadt/Alemanha), este estudo foi fundamental para que o grupo de P(e)D o qual ele gerencia pudesse otimizar e gerar redução de custos em um grupo de fórmulas de condicionadores capilares, considerados como best seller entre as marcas Clairol NNE e Wella Koleston, ambas pertencentes ao grupo Coty Inc.. As respectivas fórmulas já se encontram em fase de teste final para produção. / [en] Stearamidopropyl dimethylamine (SAPDMA) is a surfactant and it has been widely used in the cosmetics industries, particularly in hair conditioners and masks. Because of its pseudo-cationic nature, this alkyl amidoamine neutralizes the negative charges of hair strands, decreasing frizz, providing greater softness and combing force reduction. Besides that, alkyl amidoamines are excellent substitutes for traditional cationic surfactants, because they present less toxicity and improved biodegradability. However, SAPDMA is insoluble in water, as it behaves as a non-ionic molecule. At low pH values, SAPDMA becomes positively charged and, consequently, soluble in water. Currently, it is known that different acids can induce different colloid structures in formulations containing SAPDMA, which have particular physico-chemical properties. From the best of our knowledge, this phenomenon it not completely understood yet. This study intends to understand how 8 different acids can impact on colloidal structures formed by SAPDMA. In addition, we also aim to understand how fatty alcohols change the final properties of these different systems. The techniques employed to characterize all systems were conventional and polarized optical microscopy, dynamic light scattering (DLS), small angle X ray scattering (SAXS) and rheology. The results revealed that the chosen acids impact differently on the colloidal structures and that the observed differences are not limited only to pH variations, but also to different interactions between SAPDMA and the anions involved, the respective conjugated bases. The systems tendency is to form lamellar liquid-crystalline phase, but depending on the chosen acid, bilayers may have different morphologies, with changes in its curvature. So, the acid choice can impact on the formation, or not, of vesicles, besides it has a huge role in systems stability as well as the sensorial properties of the products, which are key to address the consumer needs that we aim to comply with. On one hand, bilayers can provide increased viscosity that is a property of enormous importance for application in cosmetics. On the other hand, malleable bilayers can easily close and form vesicles, which are better choice for emulsion systems, since they can easier stabilize dispersed oil droplets. This study shows the importance of better understanding systems containing SAPDMA and the impact that different acids have on them. Hence, better formulations could be developed by cosmetic industries, which already use this pseudo-cationic surfactant in several products consumed by society. Accordingly to our direct collaborator Dr. Heitor de Oliveira (Coty Inc., Darmstadt/Germany), this study was essential for the R(and)D group which he manages in order to optimize and generate cost reduction in a group of conditioner formulas considered as best seller within the brands Clairol NNE as well as Wella Koleston, both from Coty Inc.. The respective formulas are already in the final teste phase for production.

No description available.