GNNQQNY: Methodology for biophysical and structural understanding of aggregation

GNNQQNY sequence offers crucial information about the formation and structure of an amyloid fibril. In this study, we demonstrate a reproducible solubilisation protocol where the reduction of pH to 2.0 resulted in the generation of GNNQQNY monomers. The subsequent ultracentrifugation step removes the residual insoluble peptide from the homogeneous solution. This procedure ensures and allows the peptides to remain monomers till their aggregation is triggered by adjusting the pH to 7.2. The aggregation kinetics analysis showed a distinct lag-phase that is concentration-dependent, indicating nucleation-dependent aggregation kinetics. Nucleation kinetics analysis suggested a critical nucleus of size ~7 monomers at physiological conditions. The formed nucleus acts as a template for further self-assembly leading to the formation of highly ordered amyloid fibrils. These findings suggest that the proposed solubilisation protocol provides the basis for understanding the kinetics and thermodynamics of amyloid nucleation and elongation in GNNQQNY sequences. This procedure can also be used for solubilising such small amyloidogenic sequences for their biophysical studies.

ANTIMICROBIAL STUDY OF PYROLIGNEOUS EXTRACT FROM RHIZOPHORA APICULATE AGAINST URINARY TRACT PATHOGENS

Various parts of the human body are host to certain microorganism species, such as fungi and bacteria which may cause urinary tract infections (UTIs). In this research, the pyroligneous extract as antimicrobial agent on urinary tract infection-related pathogenic microorganism were studied. The Time-kill kinetics assay was used to study an antimicrobial agent over time. A series of various concentration (0 – 24%) of the pyroligneous extract was tested. Each strain’s bioactivity was quantified after 60 minutes of incubation at 22.5 oC. From the result showed that pyroligneous extract reached 100% of reduction effects with different concentration (E.faecalis (19433) at 20%, E.coli (8739) at 4%, P.vulgaris (33420) at 4%), K.pneumoniae (13883) at 4%, C.albicans (10231) at 4%). For bioprocess kinetics analysis, the highest specific reduction rate and halve rate according concentration: E.faecalis at 24% (0.1426, 0.2058), E.coli at 4% (0.1219, 0.1759), P.vulgaris at 4% (0.1311, 0.1891), K.pneumoniae at 4% (0.1175, 0.1695), C.albicans at 4% (0.1175, 0.1695).These findings shows the importance of pyroligneous extract as antimicrobial agent, especially in urinary tract infection, as a natural antimicrobial agent in public health industries.