An Evaluation of the Crystal Structure of C-terminal Truncated Apolipoprotein A-I in Solution Reveals Structural Dynamics Related to Lipid Binding

Melchior, John T.; Walker, Ryan G.; Morris, Jamie; Jones, Martin K.; Segrest, Jere P.; Lima, Diogo Borges; Carvalho, Paulo C.; Gozzo, Fábio C.; Castleberry, Mark; Thompson, Thomas B.; Davidson, W. Sean

doi:10.1074/jbc.m115.706093

Cited by 18 publications

(26 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Hence, the average -helical content in the WT decreased from ~80% in the starting model to 60% in the final model. The latter agreed with the 61% helix content determined by CD spectroscopy in (185-243) WT in solution ( Fig 5) and with previous CD (Mei & Atkinson, 2011) and MD studies of this protein (Segrest et al, 2014;Melchior et al, 2016). Similarly, all variant proteins showed a decrease in their helical content by ~20% due to partial unfolding (Fig 6), in agreement with 56-62% -helix observed in solution by far-UV CD (Fig 5).…”

Section: Mutations Induce Local Unfolding and Alter Protein Dynamics supporting

confidence: 90%

“…Flexible secondary structure in this region is consistent with two large-scale motions, one around the "top hinge" near residue Gly39 and another around the "bottom hinge" containing Gly65-Pro66 and nearby groups; such hinge motions were proposed to mediate the helixbundle opening during apoA-I binding to HDL (Mei & Atkinson, 2011;Gursky, 2013;Melchior et al, 2016). A kinked -helix at the bottom of the bundle starting at Gln69 showed partial unfolding that was particularly pronounced in Phe71Tyr variant, probably due to the local perturbation around this mutation site ( Fig 6).…”

Section: Mutations Induce Local Unfolding and Alter Protein Dynamics mentioning

confidence: 54%

“…the truncated WT provides a useful model for understanding the structure of full-length WT (Mei & Atkinson, 2011;Gursky, 2013;Melchior et al, 2017;Melchior et al, 2016). Here, we tested whether C-terminally truncated Phe71Tyr and Leu159Arg variants provided adequate structural models for their full-length counterparts, and determined how Glu34Lys, Phe71Tyr…”

Section: Globular Domains Of Variant Apoa-i Used As Structural Modelsmentioning

confidence: 99%

See 2 more Smart Citations

Molecular basis for a novel systemic form of human hereditary apoA-I amyloidosis with vision loss

Morgado

Rothschild

Panahi

et al. 2018

Preprint

View full text Add to dashboard Cite

Section: Mutations Induce Local Unfolding and Alter Protein Dynamics supporting

confidence: 90%

Section: Mutations Induce Local Unfolding and Alter Protein Dynamics mentioning

confidence: 54%

Section: Globular Domains Of Variant Apoa-i Used As Structural Modelsmentioning

confidence: 99%

See 1 more Smart Citation

Molecular basis for a novel systemic form of human hereditary apoA-I amyloidosis with vision loss

Morgado

Rothschild

Panahi

et al. 2018

Preprint

View full text Add to dashboard Cite

“…This is remarkably similar to the structural and functional organization of human apoE [47]. In the case of apoA-I, the details of this domain-domain interaction are not well understood but may involve interactions of NT- and CT-terminal helices [48,49]. Previously, we reported that the S36A mutation in apoA-I caused a significant reduction in self-association [50].…”

Section: Discussionsupporting

confidence: 68%

Transfer of C-terminal residues of human apolipoprotein A-I to insect apolipophorin III creates a two-domain chimeric protein with enhanced lipid binding activity

Horn

Ellena

Tran

et al. 2017

Biochimica et Biophysica Acta (BBA) - Biomembranes

View full text Add to dashboard Cite

Apolipophorin III (apoLp-III) is an insect apolipoprotein (18 kDa) that comprises a single five-helix bundle domain. In contrast, human apolipoprotein A-I (apoA-I) is a 28 kDa two-domain protein: an α-helical N-terminal domain (residues 1-189) and a less structured C-terminal domain (residues 190-243). To better understand the apolipoprotein domain organization, a novel chimeric protein was engineered by attaching residues 179 to 243 of apoA-I to the C-terminal end of apoLp-III. The apoLp-III/apoA-I chimera was successfully expressed and purified in E. coli. Western blot analysis and mass spectrometry confirmed the presence of the C-terminal domain of apoA-I within the chimera. While parent apoLp-III did not self-associate, the chimera formed oligomers similar to apoA-I. The chimera displayed a lower α-helical content, but the stability remained similar compared to apoLp-III, consistent with the addition of a less structured domain. The chimera was able to solubilize phospholipid vesicles at a significantly higher rate compared to apoLp-III, approaching that of apoA-I. The chimera was more effective in protecting phospholipase C-treated low density lipoprotein from aggregation compared to apoLp-III. In addition, binding interaction of the chimera with phosphatidylglycerol vesicles and lipopolysaccharides was considerably improved compared to apoLp-III. Thus, addition of the C-terminal domain of apoA-I to apoLp-III created a two-domain protein, with self-association, lipid and lipopolysaccharide binding properties similar to apoA-I. The apoA-I like behavior of the chimera indicate that these properties are independent from residues residing in the N-terminal domain of apoA-I, and that they can be transferred from apoA-I to apoLp-III.

show abstract

“…It is common for amphipathic peptides and proteins to aggregate in an orientation that provides shielding of their hydrophobic residues from the aqueous surroundings. Many exchangeable apolipoproteins accomplish this through the formation of helical bundles in the absence of lipid (13,51). B38 was found in forms ranging from a monomer to as many as 14 peptides per oligomeric complex.…”

Section: Discussionmentioning

confidence: 99%

Identification of a novel lipid binding motif in apolipoprotein B by the analysis of hydrophobic cluster domains

Gordon¹,

Pourmousa²,

Sampson³

et al. 2017

Biochimica et Biophysica Acta (BBA) - Biomembranes

View full text Add to dashboard Cite

Apolipoprotein B (apoB) is a large amphipathic protein that is the structural scaffold for the formation of several classes of lipoproteins involved in lipid transport throughout the body. The goal of the present study was to identify specific domains in the apoB sequence that contribute to its lipid binding properties. A sequence analysis algorithm was developed to identify stretches of hydrophobic amino acids devoid of charged amino acids, which are referred to as hydrophobic cluster domains (HCDs). This analysis identified 78 HCDs in apoB with hydrophobic stretches ranging from 6 to 26 residues. Each HCD was analyzed in silico for secondary structure and lipid binding properties, and a subset was synthesized for experimental evaluation. One HCD peptide, B38, showed high affinity binding to both isolated HDL and LDL, and could exchange between lipoproteins. All-atom molecular dynamics simulations indicate that B38 inserts 3.7 Å below the phosphate plane of the bilayer. B38 forms an unusual α-helix with a broad hydrophobic face and polar serine and threonine residues on the opposite face. Based on this structure, we hypothesized that B38 could efflux cholesterol from cells. B38 showed a 12-fold greater activity than the 5A peptide, a bihelical Class A amphipathic helix (EC50 of 0.2658 vs. 3.188 µM; p<0.0001), in promoting cholesterol efflux from ABCA1 expressing BHK-1 cells. In conclusion, we have identified novel domains within apoB that contribute to its lipid biding properties. Additionally, we have discovered a unique amphipathic helix design for efficient ABCA1-specific cholesterol efflux.

show abstract

An Evaluation of the Crystal Structure of C-terminal Truncated Apolipoprotein A-I in Solution Reveals Structural Dynamics Related to Lipid Binding

Cited by 18 publications

References 46 publications

Molecular basis for a novel systemic form of human hereditary apoA-I amyloidosis with vision loss

Molecular basis for a novel systemic form of human hereditary apoA-I amyloidosis with vision loss

Transfer of C-terminal residues of human apolipoprotein A-I to insect apolipophorin III creates a two-domain chimeric protein with enhanced lipid binding activity

Identification of a novel lipid binding motif in apolipoprotein B by the analysis of hydrophobic cluster domains

Contact Info

Product

Resources

About