Naslov
Surface-Core Relationships in Human Low Density Lipoprotein as Studied by Infrared Spectroscopy

Autori
Banuelos, S. ; Arrondo, J. L. ; Goi, F. M. ; Pifat, Greta

Izvornik
Journal of biological chemistry (0021-9258) 270 (1995), 16; 9192-9196

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Human LDL ; IR

Sažetak
The secondary structure of human apolipoprotein B at 37 °C is estimated to be 24% -helix, 23% - sheet, 6% -turns, 24% unordered structure, and 24% ``-strands, '' characterized by a band around 1618 cm, and consistent with extended string-like chains in contact with the lipid moiety not forming -sheets. When cooled to a temperature below the cholesteryl ester transition at 30 °C, the ordering of the low density lipoprotein core results in reversible changes in the protein conformation, decreasing the apparent amount of - helix, -strand, and unordered structure below 30 °C and increasing -sheet and - turns. Lowering the ionic strength affects the core- associated transitions, shifting their temperature from 30 to 20 °C, and modifying protein conformation below the transition. An additional thermal event is observed at 75 °C, leading to irreversible protein denaturation. In the broad temperature range between the 30 and 75 °C transitions, apolipoprotein B is stable toward both temperature and ionic strength changes. After thermal denaturation, the protein retains a certain degree of ordered structure.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

POVEZANOST RADA