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

Author(s)

M.H.B. Costa ^[1] ; W. Quintilio ^[2] ; O.A. Sant'Anna ^[3] ; A. Faljoni-Alário ^[4] ; P.S. de Araujo ^[5]

Affiliation

^[1] Instituto Butantan. Centro de Biotecnologia. Laboratório de Microesferas e Lipossomos

^[2] Instituto Butantan. Centro de Biotecnologia. Laboratório de Microesferas e Lipossomos

^[3] Instituto Butantan. Laboratório de Imunogenética - Brasil

^[4] Universidade de São Paulo. Instituto de Química - Brasil

^[5] Universidade de São Paulo. Instituto de Química - Brasil

• Document type: Journal article
• Source: Brazilian Journal of Medical and Biological Research; v. 35, n. 6, p. 727-730, 2002-06-00.
• Field of knowledge: Biological Sciences - Biophysics

Abstract

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. (AU)