Binding of Lysozyme to Phospholipid Bilayers: Evidence for Protein Aggregation upon Membrane Association

Gorbenko, Galyna; Ioffe, Valeriya M.; Kinnunen, Paavo K.J.

doi:10.1529/biophysj.106.102749

Cited by 133 publications

(113 citation statements)

References 63 publications

Supporting

Mentioning

106

Contrasting

Order By: Relevance

“…Kurts and colleagues (34) demonstrated that the mannose receptor delivered soluble Ova to an endosomal compartment equipped for cross-presentation; in contrast, macropinocytosis of Ova allowed for MHC class II presentation but not cross-presentation. HEL is not glycosylated and is presumably taken up by macropinocytosis when offered in soluble form; HEL can bind to constituents of plasma membranes, such as phospholipids (35) and glycosaminoglycans (36), but receptor-mediated uptake has not been shown. Our data indicate that soluble HEL rapidly enters late endosomes and does not remain in early endosomes for enough time to allow processing and cross-presentation; this feature of soluble HEL trafficking also hindered MHC class II presentation of type B epitopes, which are generated exclusively in early endosomes lacking the accessory molecule DM (37).…”

Section: Discussionmentioning

confidence: 99%

Targeting proteins to distinct subcellular compartments reveals unique requirements for MHC class I and II presentation

Belizaire

Unanue

2009

Proc. Natl. Acad. Sci. U.S.A.

113

108

View full text Add to dashboard Cite

Peptides derived from exogenous proteins are presented by both MHC class I and II. Despite extensive study, the features of the endocytic pathway that mediate cross-presentation of exogenous antigens on MHC class I are not entirely understood and difficult to generalize to all proteins. Here, we used dendritic cells and macrophages to examine MHC class I and II presentation of hen egg-white lysozyme (HEL) in different forms, soluble and liposome encapsulated. Soluble HEL or HEL targeted to a late endosomal compartment only allowed for MHC class II presentation, in a process that was blocked by chloroquine and a cathepsin S (CatS) inhibitor; brefeldin A (BFA) also blocked presentation, indicating a requirement for nascent MHC class II. In contrast, liposome-encapsulated HEL targeted to early endosomes entered the MHC class I and II presentation pathways. Cross-presentation of HEL in early endosomal liposomes had several unique features: it was markedly increased by BFA and by blockade of the proteasome or CatS activity, it occurred independently of the transporter associated with antigen processing but required an MHC class I surfacestabilizing peptide, and it was inhibited by chloroquine. Remarkably, chloroquine facilitated MHC class I cross-presentation of soluble HEL and HEL in late endosomal liposomes. Altogether, MHC class I and II presentation of HEL occurred through pathways having distinct molecular and proteolytic requirements. Moreover, MHC class I sampled antigenic peptides from various points along the endocytic route.cross-presentation ͉ endosome ͉ liposomes D endritic cells (DCs) and macrophages (Ms) present peptides derived from exogenous antigens on MHC class I and II (1). The subcellular localization of the antigen processing and MHC loading steps determines the molecular and proteolytic requirements for generation of a particular peptide (2, 3). In the MHC class II pathway, there is general agreement on the roles for protein synthesis, invariant chain, DM, and endosomal acidification for protein presentation, which differ from those of peptide presentation (1). Presentation by MHC class I (i.e., cross-presentation) involves unique antigen transport through the endocytic route that may or may not engage the classical MHC class I pathway (4). For example, the generation of K b -SIINFEKL complexes from ovalbumin (Ova), the most frequently tested protein, required specific components of the MHC class I processing machinery contingent on the form of antigen and the nature of the presenting cell (5, 6); some forms of Ova entered the cytosol for proteasomal processing (6-10), whereas others did not (5, 11). Although several recent reports described endosomes/phagosomes facilitating both MHC class I and II presentation, it is unclear if these compartments are unique or even extant (12).Previous studies by our laboratory demonstrated that protein encapsulation in liposomes enabled antigen targeting to specific endosomal compartments for processing and presentation on MHC class I and II (13,14). Liposomes...

show abstract

Section: Discussionmentioning

confidence: 99%

Targeting proteins to distinct subcellular compartments reveals unique requirements for MHC class I and II presentation

Belizaire

Unanue

2009

Proc. Natl. Acad. Sci. U.S.A.

113

108

View full text Add to dashboard Cite

show abstract

“…17 Immediately after its interaction within the lipid bilayer, lysozyme undergoes conformational changes with subsequent reorganization (oligomerization) that leads to vesicle clustering and amyloid fibril formation. [42][43][44][45] The concomitant presence of these effects contributes to a decrement of the lipid membrane fluidity (1/P).…”

mentioning

confidence: 99%

Lysozyme interaction with negatively charged lipid bilayers: protein aggregation and membrane fusion

et al. 2012

View full text Add to dashboard Cite

We report on the interaction of hen egg-white lysozyme (HEWL) with lipid vesicles in terms of surfaceinduced protein conformational variation and subsequent aggregation. In particular, we investigated the variations of the secondary structure of native lysozyme in the presence of liposomes with different surface charge density, resulting from different molar ratios of the zwitterionic POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) and the negatively charged POPG (1-palmitoyl-2-oleoyl-snglycero-3-phospho-(1 0 -rac-glycerol)). It is well known that the main driving force involved in the interaction between globally anionic liposomes and lysozyme is electrostatic compensation, which, in some cases, produces extended aggregation. Moreover the presence of membranes can induce unfolding in the protein. In order to understand the main determinants of such phenomena, we probed simultaneously lysozyme-induced vesicle fusion events, variations in the secondary structure of the protein and its effect on liposomal membrane fluidity. We found that above a charge-density threshold, the association with vesicles results in modifications of the native structure associated with a decrease of liposomal membrane fluidity. Electron microscopy images revealed that the above described interactions result in mesoscopic structural changes, i.e. liposome clustering and fusion, together with the appearance of elongated structures, reminiscent of fibrillar aggregates. Additionally, a confocal microscopy analysis revealed that upon interaction with giant unilamellar vesicles (GUVs) of the same lipid composition where the above interactions were observed, a prompt insertion of lysozyme in the membrane occurs, leading to vesicle clustering, with the appearance of elongated structures where both the lipid and the protein are present.

show abstract

“…5). In this sense, VP11 differs from other basic proteins, such as lysozyme, which cause rapid aggregation with lipid vesicles (60,61,62). Rather, it functions as a trigger for the binding of the large major capsid protein VP17, which in turn results in a rapid aggregation of the protein-membrane complex.…”

Section: Discussionmentioning

confidence: 99%

The Minor Capsid Protein VP11 of Thermophilic Bacteriophage P23-77 Facilitates Virus Assembly by Using Lipid-Protein Interactions

Pawlowski

Moilanen

Rissanen

et al. 2015

J Virol

View full text Add to dashboard Cite

Thermus thermophilus bacteriophage P23-77 is the type member of a new virus family of icosahedral, tailless, inner-membranecontaining double-stranded DNA (dsDNA) viruses infecting thermophilic bacteria and halophilic archaea. The viruses have a unique capsid architecture consisting of two major capsid proteins assembled in various building blocks. We analyzed the function of the minor capsid protein VP11, which is the third known capsid component in bacteriophage P23-77. Our findings show that VP11 is a dynamically elongated dimer with a predominantly ␣-helical secondary structure and high thermal stability. The high proportion of basic amino acids in the protein enables electrostatic interaction with negatively charged molecules, including nucleic acid and large unilamellar lipid vesicles (LUVs). The plausible biological function of VP11 is elucidated by demonstrating the interactions of VP11 with Thermus-derived LUVs and with the major capsid proteins by means of the dynamic-lightscattering technique. In particular, the major capsid protein VP17 was able to link VP11-complexed LUVs into larger particles, whereas the other P23-77 major capsid protein, VP16, was unable to link VP11-comlexed LUVs. Our results rule out a previously suggested penton function for VP11. Instead, the electrostatic membrane association of VP11 triggers the binding of the major capsid protein VP17, thus facilitating a controlled incorporation of the two different major protein species into the assembling capsid. IMPORTANCEThe study of thermophilic viruses with inner membranes provides valuable insights into the mechanisms used for stabilization and assembly of protein-lipid systems at high temperatures. Our results reveal a novel way by which an internal membrane and outer capsid shell are linked in a virus that uses two different major protein species for capsid assembly. We show that a positive protein charge is important in order to form electrostatic interactions with the lipid surface, thereby facilitating the incorporation of other capsid proteins on the membrane surface. This implies an alternative function for basic proteins present in the virions of other lipid-containing thermophilic viruses, whose proposed role in genome packaging is based on their capability to bind DNA. The unique minor capsid protein of bacteriophage P23-77 resembles in its characteristics the scaffolding proteins of tailed phages, though it constitutes a substantial part of the mature virion. V iruses from extremely hot environments need to develop special strategies to cope with high temperature. Hence, they provide a valuable source for the detection of novel enzymes for biotechnology and industrial processes. Their relative simple structure makes them an ideal model system for studying life at high temperatures. With respect to extreme thermophilic bacteria, the virus studied best on the structural level is P23-77, a strictly lytic phage infecting Thermus thermophilus ATCC 33923 (1, 2, 3). P23-77 is a representative of the novel Sphaerolipoviri...

show abstract

Binding of Lysozyme to Phospholipid Bilayers: Evidence for Protein Aggregation upon Membrane Association

Cited by 133 publications

References 63 publications

Targeting proteins to distinct subcellular compartments reveals unique requirements for MHC class I and II presentation

Targeting proteins to distinct subcellular compartments reveals unique requirements for MHC class I and II presentation

Lysozyme interaction with negatively charged lipid bilayers: protein aggregation and membrane fusion

The Minor Capsid Protein VP11 of Thermophilic Bacteriophage P23-77 Facilitates Virus Assembly by Using Lipid-Protein Interactions

Contact Info

Product

Resources

About