Understanding the surface of hemozoin and its synthetic analogue hematin anhydride
Notice bibliographique
Résumé
Hemozoin is a biocrystal widely studied due to its relevance as an antimalarial target, potential diagnosis biomarker, and immune modulator during malaria infection. Many investigations are carried out using the crystals isolated from in vitro or in vivo models, or by producing a synthetic analogue called hematin anhydride. Although most of the structural and morphological properties of both hemozoin and hematin anhydride are understood, little is known about their surface. Studying the surface of the crystals is critical for gaining insight into the physical and chemical interactions involved during hemozoin formation, the mechanism of action of current antimalarials, and its role as immune modulator and biomarker for diagnosis. For this reason, this work aimed to develop a critical understanding of some physicochemical properties of the surface of hemozoin and hematin anhydride. In our first study, we investigated the surface of hematin anhydride produced by two different synthesis methods, one in an aqueous medium and another under anhydrous conditions. We demonstrated that the synthesis selected to produce the crystals impacts their surface properties. The products obtained from both syntheses are non-porous and show different values of the specific surface area, elemental composition and amount of water adsorbed on the surface. We also confirmed the presence of carboxylate groups on the surface of all crystals; their amount also differs depending on sample preparations. In our next study, we collected hemozoin from in vitro cultures of Plasmodium falciparum. We cleaned the surface of the crystals from its organic contaminants by two purification procedures, one involving two additional steps than the other. The crystals showed differing surface properties in terms of composition and amount of organic contaminants adsorbed on the crystals surface. We showed that the surface of hemozoin may never be free of contaminants, either because they are part of the crystalline structure of hemozoin or because the cleaning methods introduced them. Additionally, we demonstrated that carboxylate groups play a crucial role in the interaction between hemozoin or hematin anhydride and biomolecules. In our final investigation, we isolated hemozoin from in vitro and in vivo models of Plasmodium to investigate the composition of the organic layer adhered onto the crystals surface. We demonstrated that the elemental composition of the organic layer does not vary among the crystals sources. We reported for the first time the presence or inorganic species of silicon, calcium and phosphorous associated with hemozoin. By assessing the surface speciation and possible origin of these inorganic species, we showed that silicon could be related to an unknown mechanism exploited by the parasite for defense and survival, while calcium and phosphorus may be related to Ca2+-dependent proteins and phosphorylated proteins, respectively. Finally, we proposed that the inorganic elements could be involved in hemozoin biomineralization, may influence the mode of action of some antimalarials and could play a role in the immunomodulatory properties attributed to hemozoin.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,001 | 0,000 |
| Communication savante | 0,000 | 0,001 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».