Protein-stabilized emulsions tend to be susceptible droplet aggregation in the presence of high ionic strengths or when exposed acidic gastric conditions due a reduction electrostatic repulsion between protein-coated droplets. Previously, we found that incorporating cinnamaldehyde into oil phase improved resistance whey protein isolate (WPI)-stabilized against induced by NaCl, KCl and CaCl2. In...

A binding study of nickel ions by a new recombinant human Growth Hormone (hGH), produced as an injected drug, has been done at 27˚C in NaCl solution (50 mM) using an isothermal titration calorimetry. There is a set of three identical and non-interacting binding sites for nickel ions. The intrinsic dissociation equilibrium constant and the molar enthalpy of binding are 40 μM and -16...

Sphingosine is a potent inhibitor of [3H]phorbol dibutyrate binding and protein kinase C activity in vitro and in human platelets (Hannun, Y., Loomis, C., Merrill, A., and Bell, R. (1986) J. Biol. Chem. 261, 12604-12609). Preincubation of platelets with sphingosine resulted in the inhibition of platelet secretion and second phase aggregation in response to ADP, gamma-thrombin, collagen, arachid...

Antimicrobial preservatives (APs) are included in liquid multi-dose protein formulations to combat the growth of microbes and bacteria. These compounds have been shown to cause protein aggregation, which leads to serious immunogenic and toxic side-effects in patients. Our earlier work on a model protein cytochrome c (Cyt c) demonstrated that APs cause protein aggregation in a specific manner. T...

Conformational diseases are often caused by mutations, altering protein folding and stability in vivo. We review here our recent work on the effects of mutations on the human phosphoglycerate kinase 1 (hPGK1), with a particular focus on thermodynamics and kinetics of protein folding and misfolding. Expression analyses and in vitro biophysical studies indicate that disease-causing mutations enha...

NOVEMBER 2006 M any proteins are marginally stable in solution, undergoing conformational changes due to various stresses during purification, processing and storage. Such stresses can include elevated temperature, shear strain, surface adsorption, and high protein concentration (1). Structurally altered proteins have a strong tendency to aggregate, often leading to eventual precipitation (2). ...

stable in solution, undergoing conformational changes due to various stresses during purification, processing and storage. Such stresses can include elevated temperature, shear strain, surface adsorption, and high protein concentration (1). Structurally altered proteins have a strong tendency to aggregate, often leading to eventual precipitation (2). Irreversible aggregation is a major problem ...

Disturbances in endoplasmic reticulum (ER) homeostasis create a condition termed ER stress. This activates the unfolded protein response (UPR), which alters the expression of many genes involved in ER quality control. We show here that ER stress causes the aggregation of proteins, most of which are not ER or secretory pathway proteins. Proteomic analysis of the aggregated proteins revealed enri...