Crowding and confinement have often been used synonymously with regard to their effect on the structure and dynamics of proteins. In this work, we have investigated the unfolding of the protein myoglobin (Mb) entrapped in the confinement of the water pool of AOT reverse micelles and in the presence of some commonly used macromolecular crowding agents (Ficoll 70, Dextran 70, and Dextran 40). Our results reveal that confinement effects can be quite destabilizing in nature for Mb with the extent of distortion depending on a host of factors apart from the size of the confining cage. Effects of the crowding agents on myoglobin also show a deviation from the general notion that synthetic macromolecular crowding agents are always stabilizing in nature. Ficoll 70 was observed to be particularly destabilizing in its influence on Mb unfolding. Moreover, tryptophan lifetime studies point to the fact that the Trp-heme distance in Mb might not always be a reliable probe of the secondary structural dissolution of the protein.

Human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) within the Indian subcontinent continues to spread. Although the primary clade of HIV in India differs from that of most Western countries, recent evidence suggests that the Indian clade (Clade C) also impacts neurocognitive functioning. India also has extremely high illiteracy rates that may confound detection of neurocognitive impairment, since many assessments to detect such impairment are heavily influenced by formal schooling. Among those with HIV/AIDS who have had limited educational opportunities and who are in the early stage of infection, the confounding effects of education on tests for neurocognitive impairment may be particularly salient. We therefore tested influence of HIV serostatus and education on a commonly used tool to screen for cognitive impairment, the International HIV Dementia Scale (IHDS), among Indian men and women in the catchment area of the Post Graduate Institute of Medical Education and Research (PGIMER) located in Chandigarh, India. Adjusted analyses showed that from a sample of 295 HIV-positive and HIV-negative individuals, only education was significantly associated with performance on the IHDS. HIV-negative and HIV-positive individuals, who were in the early stages of infection, performed similarly. Further development of this test to account for the effects of education on cut-off scores used to indicate possible dementia are needed, particularly for use in resource-limited settings such as India where low levels of education are widespread.

No abstract

No abstract

No abstract