RESUMEN
This work was carried out to compare the effectiveness of the methods of infrared spectroscopy in the amide I region and UV circular dichroism to the analyze the protein secondary structure by the example of linker histone H1 and bovine serum albumin (BSA). It has been shown that the application of a diamond ATR cell quantifies the proportion of α-helices and ß-structures in a good agreement with UV circular dichroism spectroscopy. It has been shown that histone H1 is able to aggregate, which results in considerable changes in its secondary structure.
Asunto(s)
Histonas/química , Albúmina Sérica Bovina/química , Animales , Bovinos , Dicroismo Circular , Histonas/aislamiento & purificación , Estructura Secundaria de Proteína , Albúmina Sérica Bovina/aislamiento & purificación , Espectrofotometría InfrarrojaRESUMEN
The 26S proteasome is a multi-subunit protein complex that consists of the catalytic 20S and regulatory 19S sub-complexes. The most well studied function of proteasomes is specific degradation of proteins. There are several purification schemes for obtaining the preparations of 26S proteasomes. An important step in purification of 26S proteasomes is concentration of the purified material for subsequent analysis of its biochemical functions. In this report we showed that the subunits composition of 26S proteasomes that have been concentrated by the different modes at the latest stage of their preparation is identical. However, the concentrating mode differently affects the functional activity of these complexes.
Asunto(s)
Hígado/química , Complejos Multiproteicos/aislamiento & purificación , Complejo de la Endopetidasa Proteasomal/aislamiento & purificación , Animales , Citoplasma/química , Complejos Multiproteicos/química , Complejo de la Endopetidasa Proteasomal/química , Proteolisis , RatasRESUMEN
We have studied the interactions of DNA with sperm-specific histones of the H1 family of sea urchin Strongylocentrotus intermedius, sea starfish Aphelasterias japonica and bivalve mollusk Chlamis islandicus using circular dichroism and DNA melting analysis. It was shown that echinoderm's sperm H1 protein has additional alpha-helical domains in its C-terminus and it demonstrates stronger DNA compaction. The differential melting curves of DNA-protein complexes have two peaks. The low temperature peak characterized the melting temperature of free DNA within the complex. The higher temperature peak characterizes the melting temperature of DNA bond to protein. DNA is found to be in the most stable state in the complexes with mollusk sperm H1 protein.
