The use of protein structure/activity relationships in the rational design of stable particulate delivery systems

• Main Authors: M.H.B. Costa, W. Quintilio, O.A. Sant'Anna, A. Faljoni-Alário, P.S. de Araujo
• Format: Article
• Language: English
• Published: Associação Brasileira de Divulgação Científica 2002-06-01
• Series: Brazilian Journal of Medical and Biological Research
• Subjects: Protein stability; Hydrophobic modification; Vaccine delivery system; Drug delivery system; Adjuvant
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000600014

The recombinant heat shock protein (18 kDa-hsp) from Mycobacterium leprae was studied as a T-epitope model for vaccine development. We present a structural analysis of the stability of recombinant 18 kDa-hsp during different processing steps. Circular dichroism and ELISA were used to monitor protein structure after thermal stress, lyophilization and chemical modification. We observed that the 18 kDa-hsp is extremely resistant to a wide range of temperatures (60% of activity is retained at 80ºC for 20 min). N-Acylation increased its ordered structure by 4% and decreased its ß-T1 structure by 2%. ELISA demonstrated that the native conformation of the 18 kDa-hsp was preserved after hydrophobic modification by acylation. The recombinant 18 kDa-hsp resists to a wide range of temperatures and chemical modifications without loss of its main characteristic, which is to be a source of T epitopes. This resistance is probably directly related to its lack of organization at the level of tertiary and secondary structures.