Abstract:
:Nonnative protein aggregation, which is a common feature in biotechnology, is also a clinical feature in more than 20 serious degenerative diseases. We studied the specific events of bovine pancreatic ribonuclease A thermal aggregation by a combination of second derivative infrared analysis and two-dimensional infrared correlation spectroscopy. By comparing the events that occur in reversible and irreversible thermal unfolding processes, certain events that were related to protein aggregation were characterized. Particularly, a band that appeared at high temperatures was assigned to the cross beta-structures in oligomers. The effect of pH, NaCl, and ethanol on ribonuclease A oligomerization as well as further aggregation induced by heat were studied and dissimilar effects of these additives were found. Basic pH and NaCl could accelerate the thermal aggregation but did not affect the formation of oligomers, whereas ethanol could increase both the aggregation rate and the population of oligomers. Our results suggested that the aggregation of RNase A might be initiated by hydrophobic interactions, controlled by oligomerization and mediated by electrostatic interactions. Moreover, the strategy of using second derivative and two-dimensional infrared analysis might provide a potential powerful tool to study the events that are directly related to the initiation of protein aggregation.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Yan YB,Zhang J,He HW,Zhou HMdoi
10.1529/biophysj.105.071530subject
Has Abstractpub_date
2006-04-01 00:00:00pages
2525-33issue
7eissn
0006-3495issn
1542-0086pii
S0006-3495(06)72434-1journal_volume
90pub_type
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