Mutational effects on inclusion body formation in the periplasmic expression of the immunoglobulin VL domain REI

Abstract

The results implicate a late, equilibrium folding intermediate in IB formation, in contrast to the apparent involvement of transient folding intermediates in other IB systems described to date. As equilibrium unfolding intermediates have also been implicated in light chain amyloidosis and deposition diseases, IB formation may prove a useful model for these human diseases.

Degradation versus Aggregation of Misfolded Maltose-binding Protein in the Periplasm of Escherichia coli

“…Several studies carried out on various proteins produced in the cytoplasm of E. coli supported a correlation of thermodynamic stability with the extent of inclusion body formation (22)(23)(24). The results described here suggest that instead of thermodynamic stability, dynamic folding properties of the newly translocated protein would better reflect the final distribution among alternative pathways.…”

“…Because misfolded proteins can induce cellular stress (2), proteolysis is a major component of the highly conserved regulatory heat shock response. Recently, a new heat shock sigma factor, E (or 24 ), involved in extra-cytoplasmic stresses has been discovered in Escherichia coli (4). In the periplasmic compartment, among many proteases, the DegP (also known as HtrA or Do) protease is the only protease, identified as a heat shock protein, involved in the degradation of misfolded proteins (3,4).…”

Amyloid-like Fibril Formation in an All β-Barrel Protein

“…Fax: 886-35-711082; E-mail: cyu@mx.nthu.edu.tw. 1 The abbreviations used are: TFE, 2,2,2-trifluoroethanol; nFGF-1, newt acidic fibroblast growth factor; ThT, thioflavin T; ANS, 1-anilino-8-napthalene sulfonate; HSQC, heteronuclear single quantum coherence; FT-IR, Fourier transform infrared spectroscopy. …”

“…Protein aggregation is a problem of importance not only in biotechnology but also in health-related industries (1,2). Globular proteins in aqueous solution often tend to aggregate under a variety of conditions of concentration, temperature, pH, and ionic strength (3)(4)(5)(6).…”

“…Several studies show proteins that are apparently unrelated in sequence and, in their native conformation, aggregate into fibrils that have characteristic amyloid-like structural and histological features (16, 20 -26). Recently, Bucciantini et al (27) demonstrated that amyloid-like fibrils of SH3 domain (from bovine phosphatidylinositol 3-kinase) induced in vitro in 25% (v/v) 2,2,2-trifluoro ethanol (TFE) 1 (under appropriate conditions) are cytotoxic to fibroblast NIH3T3 cells. The amyloid fibrils generated ex vivo are observed to seed fibrillate in cultured NIH3T3 cells (23).…”