Lipid dependant disorder-to-order conformational transitions in apolipoprotein CI derived peptides

Mendoza-Espinosa, Paola; Moreno, Abel; Castillo, Rolando; Mas‐Oliva, Jaime

doi:10.1016/j.bbrc.2007.10.112

Cited by 15 publications

(16 citation statements)

References 26 publications

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“…The surface pressure-area (Π-A) isotherms generated for compression of apoC-I monolayers at an A/W interface reveal a phase transition at Π ~ 37 mN/m and a collapse at Π ~ 47 mN/m (44, 45). Likewise, compression of apoC-I deposited on DPPC monolayers spread at an A/W interface revealed a phase transition beginning at Π ~ 24–27 mN/m and a collapse at Π ~ 49 mN/m (46–48). Brewster Angle Microscopy revealed that each phase transition was attributable to different phases of apoC-I (44–48).…”

mentioning

confidence: 98%

Apolipoprotein C-I Binds More Strongly to Phospholipid/Triolein/Water than Triolein/Water Interfaces: A Possible Model for Inhibiting Cholesterol Ester Transfer Protein Activity and Triacylglycerol-Rich Lipoprotein Uptake

2012

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ApolipoproteinC-I (apoC-I) is an important constituent of high-density lipoprotein (HDL) and is involved in the accumulation of cholesterol ester in nascent HDL by inhibiting cholesterol ester transfer protein (CETP) and potentially activating lecithin:cholesterol acyltransferase (LCAT). As the smallest exchangeable apolipoprotein (57 residues), apoC-I transfers between lipoproteins via a lipid-binding motif of two amphipathic α-helices (AαHs), spanning residues 7–29 and 38–52. To understand apoC-I’s behavior at hydrophobic lipoprotein surfaces, oil drop tensiometry was used to compare the binding to triolein/water (TO/W) and palmitoyloleoylphosphatidylcholine/triolein/water (POPC/TO/W) interfaces. When apoC-I binds to either interface, the surface tension (γ) decreases by ~16–18 mN/m. ApoC-I is exchangeable at both interfaces, desorbing upon compression and readsorbing on expansion. The maximum surface pressure at which apoC-I begins to desorb (ΠMAX) was 16.8 and 20.7 mN/m at TO/W and POPC/TO/W interfaces, respectively. This suggests that apoC-I interacts with POPC to increase affinity for the interface. ApoC-I is more elastic on POPC/TO/W than TO/W interfaces, marked by higher elasticity modulus (ε) values on oscillations. At POPC/TO/W interfaces containing an increasing POPC/TO ratio, the pressure at which apoC-I begins to be ejected increases as phospholipid surface concentration increases. The observed increase in apoC-I interface affinity due to higher degrees of apoC-I/POPC interactions may explain how apoC-I can displace larger apolipoproteins, such as apoE, from lipoproteins. These interactions allow apoC-I to remain bound to the interface at higher Πs, offering insight into apoC-I’s rearrangement on triacylglycerol-rich lipoproteins as they undergo Π changes during lipoprotein maturation by plasma factors such as lipoprotein lipase.

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confidence: 98%

Apolipoprotein C-I Binds More Strongly to Phospholipid/Triolein/Water than Triolein/Water Interfaces: A Possible Model for Inhibiting Cholesterol Ester Transfer Protein Activity and Triacylglycerol-Rich Lipoprotein Uptake

2012

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“…When apolipoproteins are exposed to air/water and lipid/water interfaces, evident disorder-to-order conformational transitions take place that might have an important impact upon HDL function [32–34]. In this sense, we have previously shown that conformational transitions observed with a series of apoA-I derived peptides stabilize and improve the enzymatic activity of LCAT [19].…”

Section: Discussionmentioning

confidence: 99%

Microenvironmentally controlled secondary structure motifs of apolipoprotein A-I derived peptides

et al. 2014

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The structure of apolipoprotein A-I (apoA-I), the major protein of HDL, has been extensively studied in past years. Nevertheless, its corresponding three-dimensional structure has been difficult to obtain due to the frequent conformational changes observed depending on the microenvironment. Although the function of each helical segment of this protein remains unclear, it has been observed that the apoA-I amino (N) and carboxy-end (C) domains are directly involved in receptor-recognition, processes that determine the diameter for HDL particles. In addition, it has been observed that the high structural plasticity of these segments might be related to several amyloidogenic processes. In this work, we studied a series of peptides derived from the N- and C-terminal domains representing the most hydrophobic segments of apoA-I. Measurements carried out using circular dichroism in all tested peptides evidenced that the lipid environment promotes the formation of α-helical structures, whereas an aqueous environment facilitates a strong tendency to adopt β-sheet/disordered conformations. Electron microscopy observations showed the formation of amyloid-like structures similar to those found in other well-defined amyloidogenic proteins. Interestingly, when the apoA-I peptides were incubated under conditions that promote stable globular structures, two of the peptides studied were cytotoxic to microglia and mouse macrophage cells. Our findings provide an insight into the physicochemical properties of key segments contained in apoA-I which may be implicated in disorder-to-order transitions that in turn maintain the delicate equilibrium between both, native and abnormal conformations, and therefore control its propensity to become involved in pathological processes.

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“…Apo CI in solution shows a clear circular dichroism (CD) signal associated with a high degree ofhelix structure (Bolaños-García et al, 1999). However, when peptides ALDO, ARELI and SAK (Mendoza-Espinosa et al, 2008) were tested under the same experimental conditions, they showed no defined secondary structure and remain non-structured independently of pH, temperature and ionic strength. Interestingly, despite that these peptides have an amphipathic character and high hydrophobic moment values (μH > 0.315 kcal/mol), they remain completely unfolded in solution (see Fig.…”

Section: Apo CI Derived Peptides-lipid Interactionmentioning

confidence: 99%

“…As described below, this has been achieved employing Langmuir monolayers in conjunction with Brewster angle microscopy (BAM), atomic force microscopy (AFM) of Apos LB films (Bolaños-García et al, 1999Mas-Oliva et al, 2003;Xicohtencatl-Cortes et al, 2004a), grazing incidence X-ray diffraction on protein monolayers (Ruíz-García et al, 2003), and surface force measurements (SFA) (Campos-Terán et al, 2004;Ramos et al, 2008). Because at that time, we were unable to define whether the secondary structure of specific segments of Apolipoprotein CI (ApoCI) and AII (Apo AII) remained stable independently of their position at air/water and lipid/water interfaces, recently we have addressed the possibility that these segments responding to specific environmental changes and following disorder-to-order transitions might function as molecular switches that trigger function (Mendoza-Espinosa et al, 2008, 2009. Moreover, following the same approach with specific peptides synthesized from the reported structure of Apolipoprotein AI (Apo AI), we have found that when left in water at 4°C a very slow disorder-to-order transition develops over the course of days, from a fully disordered state to a well-developed -sheet secondary structure.…”

Section: Introductionmentioning

confidence: 99%

Conformational and Disorder to Order Transitions in Proteins: Structure / Function Correlation in Apolipoproteins

Campos‐Terán¹,

Espinosa²,

Mas³

et al. 2012

Protein-Protein Interactions - Computational and Experimental Tools

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Lipid dependant disorder-to-order conformational transitions in apolipoprotein CI derived peptides

Cited by 15 publications

References 26 publications

Apolipoprotein C-I Binds More Strongly to Phospholipid/Triolein/Water than Triolein/Water Interfaces: A Possible Model for Inhibiting Cholesterol Ester Transfer Protein Activity and Triacylglycerol-Rich Lipoprotein Uptake

Apolipoprotein C-I Binds More Strongly to Phospholipid/Triolein/Water than Triolein/Water Interfaces: A Possible Model for Inhibiting Cholesterol Ester Transfer Protein Activity and Triacylglycerol-Rich Lipoprotein Uptake

Microenvironmentally controlled secondary structure motifs of apolipoprotein A-I derived peptides

Conformational and Disorder to Order Transitions in Proteins: Structure / Function Correlation in Apolipoproteins

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