Liposome-Recruited Activity of Oxidized and Fragmented Superoxide Dismutase

Abstract

The peptide fragment of H2O2-treated Cu,Zn-superoxide dismutase (SOD) was found to be reactivated with liposomes prepared by 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). The fragmentation of SOD was observed by 2 mM H2O2 treatment as well as by SOD inactivation and the loss of an alpha-helix in the neighborhood of its activity center. The H2O2-treated SOD, which lost its activity at different incubation times, was dramatically reactivated only by adding POPC liposomes, resulting in 1.3-2.8 times higher enzymatic activity. The ultrafiltration analysis of H2O2-treated SOD co-incubated with liposomes shows that some specific peptide fragments of the oxidized SOD can interact with POPC liposomes. A comparison of the fractions detected in reverse-phase chromatography shows that specific SOD fragments are able to contribute to the reactivation of oxidized and fragmented SOD in the presence of POPC liposomes. The liposomes can recruit the potentially active fragment of SOD among the lethally damaged SOD fragments to elucidate the antioxidative function.

Use Liposome as a Designable Platform for Molecular Recognition ~ from “Statistical Separation” to “Recognitive Separation” ~

“…"raft" domains) in cells has attracted much attention because of its implications for membrane-related processes, including bacterial and viral infections and signal transductions [22]. Recent studies have also revealed that the lipid membranes can activate the biomacromolecules and regulate their functions [6][7][8][9][39][40]. Liposomes have been intensely studied as a biomimetic environment of lipid bilayers.…”

“…A liposome membrane is effective in its use as a platform to perform the above purpose because it looks after the fundamental characteristics of a conventional extraction system and the recognition surface of the biomolecule ( Figure 1). In practice, there are many reports on the possible role of a liposome membrane to recognize various molecules , such as asymmetric recognition [56-57], metal affinity [4], peptide recognition [7,58], enzyme-like function [8,59], RNA recognition [6,42,48], and others [9,28] (Figure 8). membrane modules [61], and hydrogel immobilization of the liposomes at high concentration ( Figure 9) [62].…”

“…There are some examples of the ordered structure, created on the liposome membrane through the control of its combined interactions with the target molecules [6][7][8][9]. It is rational to use the membrane surface of a liposome membrane system as a platform for the recognition of biomolecules to create a new order on its surface.…”

Characterization of the physicochemical properties of phospholipid vesicles prepared in CO2/water systems at high pressure

“…Emergent properties arising from the membrane of the liposome (vesicle) have been introduced, where the vesicle (liposome) membrane can selectively interact with various types of molecules under particular conditions. 12 The important functions of vesicles include (1) interaction with proteins (enzymes) and nucleotides, [13][14][15][16][17] (2) storage of encapsulated molecules, 1,18 and (3) fusion with membranes. 19 Vesicle membranes are dynamic, for example, vesicles composed of 1,2-dimylistoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) possess phase transition temperatures (T m ) at 23.6 and 41.…”

Comparison of Partitioning Behaviors of L-/D-Trpin Solvent-Water System and Liposome Membrane System

“…There have been several studies on the up-or down-regulation of the function of the gene expression machinery [5], RNA [6], peptides [7] and enzymes [8] and hydrophobic interactions [9][10]. However, each contribution requires investigation in a simpler target molecule.…”