Molecular evolutionary and structural analysis of familial exudative vitreoretinopathy associated FZD4 gene

Abstract Background Frizzled family members belong to G-protein coupled receptors and encode proteins accountable for cell signal transduction, cell proliferation and cell death. Members of Frizzled receptor family are considered to have critical roles in causing various forms of cancer, cardiac hypertrophy, familial exudative vitreoretinopathy (FEVR) and schizophrenia. Results This study investigates the evolutionary and structural aspects of Frizzled receptors, with particular focus on FEVR associated FZD4 gene. The phylogenetic tree topology suggests the diversification of Frizzled receptors at the root of metazoans history. Moreover, comparative structural data reveals that FEVR associated missense mutations in FZD4 effect the common protein region (amino acids 495–537) through a well-known phenomenon called epistasis. This critical protein region is present at the carboxyl-terminal domain and encompasses the K-T/S-XXX-W, a PDZ binding motif and S/T-X-V PDZ recognition motif. Conclusion Taken together these results demonstrate that during the course of evolution, FZD4 has acquired new functions or epistasis via complex patter of gene duplications, sequence divergence and conformational remodeling. In particular, amino acids 495–537 at the C-terminus region of FZD4 protein might be crucial in its normal function and/or pathophysiology. This critical region of FZD4 protein may offer opportunities for the development of novel therapeutics approaches for human retinal vascular disease

Allantoin eutectics with choline chloride and zinc chloride: interactions and wound healing applications

Allantoin eutectics with choline chloride (ACM) and zinc chloride (AZM) are reported. The solid–liquid phase diagram showed the eutectic point in allantoin-rich region (Xallantoin = 0.9) for ACM. In AZM, the eutectic formation occurred in the equimolar mixture. The H-bonded template in pure allantoin was disrupted upon addition of choline chloride or zinc chloride, which led to freezing point depression. Classical and non-classical hydrogen bonding, electrostatic and donor–acceptor interactions existed among the components. Infrared vibrational frequencies indicated the involvement of ureido NH2, and ring carbonyl of allantoin, OH group of choline chloride, and Zn2+ in interactions. Thermogravimetric analysis showed that among equimolar mixtures ACM5 was more stable than AZM5. An increase in zinc chloride content markedly altered the thermal stability in AZM. Both categories of eutectics were universally soluble in dimethyl sulfoxide. Skin wounds in rabbit models were healed more effectively by concoctions containing relatively smaller percentages of eutectics