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Iwahashi M, Takebayashi S, Umehara A, Kasahara Y, Minami H, Matsuzawa H, Inoue T, Takahashi H. Dynamical dimer structure and liquid structure of fatty acids in their binary liquid mixture: dodecanoic and 3-phenylpropionic acids system. Chem Phys Lipids 2004; 129:195-208. [PMID: 15081860 DOI: 10.1016/j.chemphyslip.2004.01.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2003] [Revised: 01/28/2004] [Accepted: 01/28/2004] [Indexed: 11/29/2022]
Abstract
Dimer structure and liquid structure of fatty acids in the binary liquid mixture of dodecanoic (LA) and 3-phenylpropionic acids (PPA) were studied through the measurements of DSC, self-diffusion coefficient (D), density, viscosity, 13C NMR spin-lattice relaxation time, small-angle X-ray scattering (SAXS), and small-angle neutron scattering (SANS). The phase diagram of LA/PPA mixture exhibited a typical eutectic pattern, which means that LA and PPA are completely immiscible in solid phase. In the liquid phase of the LA/PPA mixture, D of LA always differed from that of PPA irrespective of their compositions. This exhibited that, in the liquid phase of the binary mixture of fatty acids giving a complete eutectic in the solid phase, the fatty acid dimers are composed of the same fatty acid species irrespective of their compositions. The liquid structure of the LA/PPA mixture was clarified through the SAXS and also the SANS measurements.
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Affiliation(s)
- Makio Iwahashi
- Department of Chemistry, School of Science, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa-ken 228-8555, Japan.
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Binding of ethyl oleate to low density lipoprotein, phospholipid vesicles, and albumin: a 13C NMR study. J Lipid Res 1996. [DOI: 10.1016/s0022-2275(20)39129-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Toussaint JF, Southern JF, Fuster V, Kantor HL. 13C-NMR spectroscopy of human atherosclerotic lesions. Relation between fatty acid saturation, cholesteryl ester content, and luminal obstruction. ARTERIOSCLEROSIS AND THROMBOSIS : A JOURNAL OF VASCULAR BIOLOGY 1994; 14:1951-7. [PMID: 7981185 DOI: 10.1161/01.atv.14.12.1951] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Previous investigations have used 13C-nuclear magnetic resonance (NMR) spectroscopy to demonstrate the similarities between lipoproteins and the mobile lipids of atheroma. In this study, we tested the hypothesis that 13C-NMR changes are related to indices of histological severity. We classified 20 human arteries according to their obstruction ratio (OR), defined as the ratio of the plaque area to the area delimited by the external elastic lamina. In group A, OR was < 40%, and in group B, OR was > 40%. We analyzed at 9.4 T the resonances of unsaturated (UFA) and polyunsaturated (PUFA) carbons, the resonances of the carbons 19 and 21 (C19, C21) of cholesteryl esters (CE), the methine carbon peak of fatty acids (CH2)n, the choline peak from phospholipids (PL), and the glycerol peak from triglyceride (TG). The UFA/PUFA, UFA/(CH2)n, and PUFA/(CH2)n ratios are markers of fatty acid saturation. (C19, C21)/(CH2)n, choline/(CH2)n, and glycerol/(CH2)n are indices of CE, PL, and TG content, respectively. UFA/PUFA in group A is 1.15 +/- 0.34 versus 1.63 +/- 0.32 in group B (P = .005). PUFA/(CH2)n is 0.26 +/- 0.10 in group A versus 0.16 +/- 0.04 in group B (P = .049). C19, C21/(CH2)n in group A is 0.32 +/- 0.15 versus 0.63 +/- 0.23 for group B (P = .003). No significant difference was found in UFA/(CH2)n or in the TG or PL ratios. 13C spectral examination of human atherosclerosis demonstrates decreased resonances for polyunsaturated fatty acyl chains and cholesteryl esters with increasing obstruction.
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Fan TW, Clifford AJ, Higashi RM. In vivo 13C NMR analysis of acyl chain composition and organization of perirenal triacylglycerides in rats fed vegetable and fish oils. J Lipid Res 1994. [DOI: 10.1016/s0022-2275(20)41182-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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5
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Bhamidipati S, Hamilton J. NMR studies of phospholipase C hydrolysis of phosphatidylcholine in model membranes. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)53794-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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6
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Phospholipid/cholesteryl ester microemulsions containing unesterified cholesterol: model systems for low density lipoproteins. J Lipid Res 1990. [DOI: 10.1016/s0022-2275(20)42784-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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7
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Deckelbaum RJ, Hamilton JA, Moser A, Bengtsson-Olivecrona G, Butbul E, Carpentier YA, Gutman A, Olivecrona T. Medium-chain versus long-chain triacylglycerol emulsion hydrolysis by lipoprotein lipase and hepatic lipase: implications for the mechanisms of lipase action. Biochemistry 1990; 29:1136-42. [PMID: 2322552 DOI: 10.1021/bi00457a006] [Citation(s) in RCA: 128] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
To explore how enzyme affinities and enzyme activities regulate hydrolysis of water-insoluble substrates, we compared hydrolysis of phospholipid-stabilized emulsions of medium-chain (MCT) versus long-chain triacylglycerols (LCT). Because substrate solubility at the emulsion surface might modulate rates of hydrolysis, the ability of egg yolk phosphatidylcholine to solubilize MCT was examined by NMR spectroscopy. Chemical shift measurements showed that 11 mol % of [13C]carbonyl enriched trioctanoin was incorporated into phospholipid vesicles as a surface component. Similar methods with [13C]triolein showed a maximum solubility in phospholipid bilayers of 3 mol % (Hamilton & Small, 1981). Line widths of trioctanoin surface peaks were half that of LCT, and relaxation times, T1, were also shorter for trioctanoin, showing greater mobility for MCT in phospholipid. In assessing the effects of these differences in solubility on lipolysis, we found that both purified bovine milk lipoprotein lipase and human hepatic lipase hydrolyzed MCT at rates at least 2-fold higher than for LCT. With increasing concentrations of MCT, saturation was not reached, indicating low affinities of lipase for MCT emulsions, but with LCT emulsion incubated with lipoprotein lipase, saturation was reached at relatively low concentration, demonstrating higher affinity of lipase for LCT emulsions. Differences in affinity were also demonstrated in mixed incubations where increasing amounts of LCT emulsion resulted in decreased hydrolysis of MCT emulsions. Increasing MCT emulsion amounts had little or no effect on LCT emulsion hydrolysis.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- R J Deckelbaum
- Department of Pediatrics, Columbia University, New York, New York 10032
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8
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Cabral DJ, Hamilton JA, Small DM. The ionization behavior of bile acids in different aqueous environments. J Lipid Res 1987. [DOI: 10.1016/s0022-2275(20)38839-8] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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9
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Treleaven WD, Parmar YI, Gorrissen H, Cushley RJ. Orientational order of cholesteryl oleate in low-density lipoprotein observed by 2H-NMR. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 877:198-210. [PMID: 3718998 DOI: 10.1016/0005-2760(86)90135-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Cholesteryl oleate, selectively deuterated at various positions along the acyl chain, has been incorporated into fresh human serum low-density lipoprotein (LDL2). Temperature-dependent 2H-NMR spectra were recorded between 15 and 45 degrees C. For deuterons at C-2' and C-5' of the acyl chain, two 2H-NMR spectral components, a broad and a narrow signal, are observed. This is interpreted as reflecting the coexistence of two cholesteryl ester regions in the LDL2 core which possess different degrees of order. The C-2H bond order parameters, SCD, are approx. 0.12-0.20 for the more ordered region and approx. 0.04-0.06 for the less ordered region. Longitudinal relaxation times, T1, of deuterated cholesteryl oleate are found to increase between C-8' and the terminal -C2H3 group, which is consistent with an increased rate of chain motion toward the free ends of the ester acyl chains.
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Abstract
High-resolution, proton-decoupled 13C nuclear magnetic resonance spectra (90.55 MHz) of human low-density lipoprotein (LDL) have been employed to investigate the physical state of unesterified cholesterol molecules in this particle. Approximately half of the cholesterol molecules in LDL were replaced with [4-13C]cholesterol by exchange from Celite. About two-thirds of the cholesterol molecules contribute to a resonance at delta 41.8 from the C-4 atom. This signal is assigned to cholesterol molecules located at the surface of the LDL particle in a mixed monolayer with phospholipid molecules; the spin-lattice relaxation of the C-4 nucleus of such cholesterol molecules is enhanced by the presence of Mn2+ ions in the aqueous phase. The remaining one-third of the cholesterol molecules are apparently neither associated with phospholipid nor exposed to the aqueous phase; these cholesterol molecules are presumed to be located in the core of the particle. Cholesterol molecules in the two microenvironments are in slow exchange on the NMR time scale but in fast exchange on a biological time scale, so that the cholesterol molecules in LDL behave physiologically as one pool. There is a loss of about 20% of the intensity of the N(CH3)3 resonance from phosphatidylcholine and sphingomyelin molecules in the LDL spectrum; this is attributed to the presence of apolipoprotein B in the surface of LDL particles, which may immobilize some of the phospholipid polar groups. Spin-lattice relaxation time measurements suggest that the fast axial motions of cholesterol molecules in the surface of LDL are the same as in high-density lipoprotein (HDL).(ABSTRACT TRUNCATED AT 250 WORDS)
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12
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Katagiri C, Kimura J, Murase N. Structural studies of lipophorin in insect blood by differential scanning calorimetry and 13C nuclear magnetic relaxation measurements. Location of hydrocarbons. J Biol Chem 1985. [DOI: 10.1016/s0021-9258(17)38748-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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13
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13C- and 1H-NMR studies of osmoregulation in Dunaliella. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 1985. [DOI: 10.1016/0167-4889(85)90001-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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14
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Brainard JR, Knapp RD, Morrisett JD, Pownall HJ. 13C NMR studies of the thermal properties of a model high density lipoprotein. Apolipoprotein A-I-dimyristoylphosphatidylcholine complex. J Biol Chem 1984. [DOI: 10.1016/s0021-9258(18)90970-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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15
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Parmar YI, Gorrissen H, Wassall SR, Cushley RJ. Molecular motion and conformation of cholesteryl esters in reconstituted high density lipoprotein by deuterium magnetic resonance. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(18)33087-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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16
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Zan YP, Condrea E, Yang CC, Rosenberg P. Phospholipid hydrolysis in serum lipoproteins by a basic phospholipase A2 from Naja nigricollis snake venom and an acidic phospholipase A2 from Naja naja atra snake venom. Toxicon 1983; 21:481-90. [PMID: 6623492 DOI: 10.1016/0041-0101(83)90126-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Apparent Km and Vmax values for PC and PE hydrolysis were determined following exposure of HDL, LDL, and VLDL to a basic phospholipase A2 from N. nigricollis snake venom and an acidic phospholipase A2 from N. nigricollis snake venom and an acidic phospholipase A2 from N. n. atra snake venom. Both enzymes hydrolyzed the lipoprotein phospholipids approximately as fast as they hydrolyzed pure phospholipids in mixed micelles, however, the N. nigricollis enzyme, which has a much stronger anticoagulant effect than the N. n. atra enzyme, had lower apparent Vmax values. These values were highest for phospholipids in VLDL and lowest for HDL, however, the differences between the lipoproteins were relatively small with the N. nigricollis enzyme while the differences were much larger with the N. n. atra enzyme. Fractions of the two enzymes in which varying numbers of lysines were carbamylated showed much larger differences in relative rates of phospholipid hydrolysis in HDL, LDL and VLDL. Triton X-100 eliminates these differences in rates of hydrolysis. These results are discussed in terms of the differences in the organized structure of the lipoprotein classes and in the penetration ability of the phospholipases.
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17
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Wassall SR, Treleaven WD, Parmar YI, Cushley RJ. Deuterium magnetic resonance of human plasma lipoproteins. Biochem Biophys Res Commun 1982; 107:429-34. [PMID: 7126221 DOI: 10.1016/0006-291x(82)91509-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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18
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Pifat G, Brnjas-Kraljević J, Herak J, Jürgens G, Holasek A. Proton relaxation study of molecular motions in low density lipoproteins. Int J Biol Macromol 1981. [DOI: 10.1016/0141-8130(81)90043-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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19
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Interaction of cholesterol and cholesterol analogs with egg phosphatidylcholine in a lipid solvent. J Biol Chem 1981. [DOI: 10.1016/s0021-9258(19)69050-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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20
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A. Keniry M, Smith R. A 13C NMR spin-lattice relaxation study of the interaction of myelin proteins with lipid vesicles. Biophys Chem 1980. [DOI: 10.1016/0301-4622(80)80046-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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22
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Brainard JR, Knapp RD, Patsch JR, Gotto AM, Morrisett JD. Dynamics of lipid motions in high-density lipoprotein subfractions HDL2 and HDL3: magnetic resonance studies. Ann N Y Acad Sci 1980; 348:299-317. [PMID: 6249173 DOI: 10.1111/j.1749-6632.1980.tb21309.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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23
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Kirchhausen T, Fless G, Scanu AM. The structure of plasma low density lipoproteins: experimental facts and interpretations--a minireview. Lipids 1980; 15:464-7. [PMID: 6772911 DOI: 10.1007/bf02534073] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
From data on size and chemical composition, low density lipoprotein (LDL) can be described as a spherical particle having cholesteryl esters and triglycerides contained in a spherical core covered by the closely packed hydrophobic ends of phospholipids and unesterified cholesterol, while the head groups of the phospholipids, together with protein, occupy the surface. Such a model is compatible with early small angle X-ray and neutron scattering studies which, by prostulating spherical symmetry, assigned the LDL constituents to locations predicted from the radial electron density distribution. However, the concept of spherical symmetry, as applied to LDL structure, was recently challenged by results obtained from freeze-etching electron microscopy and small angle X-ray scattering experiments. Novel interpretations of these data suggest that the surface of LDL contains 4 electron-dense globules, located at tetrahedral positions, which have a capacity for structural remodeling at least as a function of the 2 temperatures studied (21C and 41C). It is reasonable to presume that the LDL protein (apo LDL) plays a role in the organization of the surface and overall LDL structure. However, until the chemical properties of apoLDL, and its behavior in solution and at the water-lipid interface are better understood, the validity of the proposed models cannot be assessed.
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24
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Lipid dynamics in human low density lipoproteins and human aortic tissue with fibrous plaques. A study by high field 13C NMR spectroscopy. J Biol Chem 1979. [DOI: 10.1016/s0021-9258(18)50615-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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25
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Hauser H, Kostner GM. Structural organization of free and esterified cholesterol in human high density lipoproteins. A 100.6 MHz 13C NMR study. BIOCHIMICA ET BIOPHYSICA ACTA 1979; 573:375-81. [PMID: 221035 DOI: 10.1016/0005-2760(79)90070-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The structural organization of free and esterified cholesterol in human high density lipoproteins has been studied by high-field 1H and 13C NMR. The measurements are consistent with free cholesterol being present in at least two different environments. Part of the free cholesterol is oriented in the outer surface layer of the high density lipoprotein particle in contact with phospholipid or apoprotein, or both. The rest is probably present in the liquid, hydrophobic core of the HDL particle.
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26
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Schroeder F, Goh E, Heimberg M. Regulation of the surface physical properties of the very low density lipoprotein. J Biol Chem 1979. [DOI: 10.1016/s0021-9258(17)30245-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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27
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28
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Kon SH. Biological autoxidation. II. Cholesterol esters as inert barrier antioxidants. Self-assembly of porous membrane sacs. An hypothesis. Med Hypotheses 1978; 4:559-80. [PMID: 748727 DOI: 10.1016/0306-9877(78)90047-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The antioxidation defenses recognized thus far appear too weak. Needed are inert barriers to encapsulate foci of activated oxygen (FAOs) and contain their spreading. These capsules must: 1. self-assemble nonenzymatically and spontaneously in face of adversity; 2. resist oxidation and dissolution in water; and 3. be moderately fluid and elastic enough to withstand flexing by tissues. Evidence shows activated oxygen: a. is produced by common cholesterolester (CE)-raising agents; b. boosts accumulation of CEs; and c. splits low-density lipoproteins (LDL), thus releasing CE-rich coalescence-prone lipid micelles. I am proposing that CEs, combined with polar lipids, are uniquely suited to form inert-lipid antioxidation barriers (ILABs). Porous ILAB capsules self-assemble from lipid micelles released by oxidatively degraded LDL. The capsules are thermodynamically unstable but elastic, durable and capable of self-repair through oxidation of ambient LDL. All capsules tend to contract into spheres. Enclosed needle-like "foreign bodies", such as asbestos, puncture the contracting capsules. Hence the odd bulbous architecture of asbestos bodies. ILABs protect from--and their failure initiates and promotes--carcinogenesis and atherosclerosis. ILABs may be mediators of membrane biogenesis. The loss of arterial flexibility in atherosclerosis protects ILAB capsules from breakage.
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29
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Hamilton J, Cordes E. Molecular dynamics of lipids in human plasma high density lipoproteins. A high field 13C NMR study. J Biol Chem 1978. [DOI: 10.1016/s0021-9258(17)34676-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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30
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Natural abundance 13C nuclear magnetic resonance studies of human plasma high density lipoproteins. J Biol Chem 1978. [DOI: 10.1016/s0021-9258(17)34787-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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31
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Hamilton J, Oppenheimer N, Cordes E. Carbon-13 nuclear magnetic resonance studies of cholesteryl esters and cholesteryl ester/triglyceride mixtures. J Biol Chem 1977. [DOI: 10.1016/s0021-9258(17)40938-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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32
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Morrisett JD, Jackson RL, Gotto AM. Lipid-protein interactions in the plasma lipoproteins. BIOCHIMICA ET BIOPHYSICA ACTA 1977; 472:93-133. [PMID: 329882 DOI: 10.1016/0304-4157(77)90015-6] [Citation(s) in RCA: 227] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The purpose of this review has been to discuss new information about the mechanism of lipid and apoprotein interaction in the plasma lipoproteins. A special form of the amphipathic helix has been identified as a major structural element of the apolipoproteins sequenced to date. Evidence is reviewed concerning the role of the amphipathic helix in the binding to phospholipids. Several different models for the organization of the components of HDL, LDL and LP-X have evolved from extensive structural studies. Resolution of the differences among these models will require additional experimental testing. Verification of models based on the study of reconstituted HDL will require rigorous proof of native structure in these particles. A detailed description of the molecular organization of the lipid and protein constituents of the plasma lipoproteins is still lacking. Further structural and sequence studies with apoB and the "arginine-rich" protein are needed. Crystallization of an apoprotein or lipoprotein and determination of the three-dimensional structure would be a major achievement. With such further detailed structural information, it may then be possible to correlate changes in structure with determinants of metabolism.
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Middelhoff G, Augustin J, Klose G, Greten H. [Lipid-protein-interactions of human apolipoproteins-structural aspects and models of lipoproteins (author's transl)]. KLINISCHE WOCHENSCHRIFT 1977; 55:149-60. [PMID: 320378 DOI: 10.1007/bf01469135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The plasma lipoproteins are complex macromolecular structures which play an essential role in fat transport and in energy and membrane metabolism of higher organized organisms. Much has been learned in the last decade about the structural and functional interrelationships of the different lipoprotein classes. Their protein moieties, the so-called apolipoproteins, have been purified and characterized, the primary structure of four of them is known. Initial recombination experiments showed a considerable potential of the (unfractionated) lipoprotein protein to bind to lipids and to form particles similar to native lipoproteins. Further binding experiments performed in several laboratories with the purified A- and C-apolipoproteins and different physico-chemically well defined lipids have lead to the identification of lipid binding sites within the protein molecules and the formation of amphipathic helices upon and during lipid binding. This possible common mechanism of lipid-protein fractions forms the basis of a recently proposed model of one lipoprotein class, namely the high density lipoproteins (HDL). The significance of protein-protein-interactions in the formation and maintenance of these lipoprotein particles is still unknown. Whether disturbed lipid protein interactions lead to structural and/or functional alterations of the corresponding lipoproteins is a topic of discussion. The pertinent literature is listed in this paper and the physiological relevance of these studies and their clinical aspects will be presented.
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Hamilton JA, Oppenheimer NJ, Addleman R, Clouse AO, Cordes EH, Steiner PM, Glueck CJ. High-field 13C NMR Studies of certain normal and abnormal human plasma lipoproteins. Science 1976; 194:1424-7. [PMID: 188128 DOI: 10.1126/science.188128] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
High-field (63.4 kilogauss) Fourier transform nuclear magnetic resonance spectroscopy 13C in natural abundance has been used to study the structural organization and molecular dynamics of constituent lipids of normal human very low-density lipoproteins (VLDL) and low-density lipoproteins (LDL). The same method was used to study the abnormal beta-VLDL of two type III hyperlipoproteinemia patients having markedly differing ratios of VLDL cholesterol to triglyceride (0.3 and 0.6, respectively). Resolution obtained at 63.4 kilogauss has made possible the assignment of several additional resonances of cholesterol ring carbon atoms, not resolved in earlier studies at lower fields, in the VLDL spectra. The rotational reorientation of the ring portion of cholesteryl esters in VLDL (normal) and beta-VLDL (abnormal) is not highly anisotropic and is similar to that for cholesteryl esters disolved in excess triolein. The rotations of cholesteryl esters in LDL are more highly anisotropic and significantly more restricted. The results suggest that the structural organization of the lipid components in beta-VLDL resembles that found in normal VLDL but differs significantly from that for normal LDL.
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Sears B, Deckelbaum RJ, Janiak MJ, Shipley GG, Small DM. Temperature-dependent 13C nuclear magnetic resonance studies of human serum low density lipoproteins. Biochemistry 1976; 15:4151-7. [PMID: 183812 DOI: 10.1021/bi00664a003] [Citation(s) in RCA: 42] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The natural abundance 13C nuclear magnetic resonance (NMR) spectrum of human serum low density lipoproteins (LDL) shows significant temperature-dependent changes. These temperature-dependent spectra have been used to monitor changes in the organization of cholesterol esters within the LDL particle. Comparison with 13C NMR spectra of both cholesterol linoleate and an aqueous codispersion of cholesterol linoleate and egg phosphatidylcholine suggests that at low temperatures (10 degrees C), the cholesterol esters in LDL are organized in a smectic-like, liquid-crystalline arrangement. At temperatures above the order-disorder transition exhibited by the cholesterol esters of LDL, the cholesterol esters appear to be partially melted but still are motionally restricted compared with liquid cholesterol esters.
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36
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Huang CH. Roles of carbonyl oxygens at the bilayer interface in phospholipid-sterol interaction. Nature 1976; 259:242-4. [PMID: 1250357 DOI: 10.1038/259242a0] [Citation(s) in RCA: 84] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Jonas A. Microviscosity of lipid domains in human serum lipoproteins. BIOCHIMICA ET BIOPHYSICA ACTA 1976; 486:10-22. [PMID: 1009129 DOI: 10.1016/0005-2760(77)90065-0] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Microviscosities for the hydrophobic lipid regions of human serum lipoproteins and for dispersions of lipids extracted from the lipoproteins have been determined using fluorescence polarization measurements with 1,6-diphenyl-1,3,5-hexatriene, a rod-like molecule, as the main fluorescent probe. Additional microviscosity measurements were carried out on LP-X, an abnormal human lipoprotein characteristic of cholestasis. Perylene, a disc-shaped fluorescent probe, was used with intact human lipoproteins in order to confirm relative microviscosity values measured with 1,6-diphenyl-1,3,5-hexatriene and to estimate the anisotropy of the lipid domains. Logarithmic plots of microviscosity against the inverse of absolute temperature, over the range of 0-40 degrees C, gave no indication of phase transitions and yielded activation energy values for all human lipoproteins and for the isolated lipids. The microviscosity results at 25 degrees C range from a high value of 6.1 +/- 0.9 P for low density lipoprotein down to 1.0 +/- 0.2P for chylomicrons, when 1,6-diphenyl-1,3,5-hexatriene is used as the probe. Activation energies vary from 9 kcal per mol to 6 kcal per mol for the intact lipoproteins. In contrast, isolated lipids have microviscosities from 2.4 +/- 0.3P for low density lipoprotein lipids to 1.0 +/- 0.2P for chylomicron lipids, with activation energies around 6 kcal per mol. The absolute microviscosity values indicate fluid yet viscous and anisotropic lipid domains in higher density lipoproteins, and more fluid and disordered states for isolated lipids and chylomicrons. Differences in microviscosities between the intact lipoproteins and isolated lipids can be attributed to the effects of proteins in restricting the mobility of lipids, these effects are strongest for low density lipoproteins, followed by high density lipoproteins, LP-X, very low density lipoproteins, and chylomicrons. Flow activation energies are throught to reflect intermolecular interactions, and are again higher for the higher density lipoproteins than for isolated lipids, or for chylomicrons.
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13C Nmr Spectroscopy in Macromolecular Systems of Biochemical Interest. ADVANCES IN PHYSICAL ORGANIC CHEMISTRY 1976. [DOI: 10.1016/s0065-3160(08)60215-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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Hull WE, Sykes BD. Fluorotyrosine alkaline phosphatase: internal mobility of individual tyrosines and the role of chemical shift anisotropy as a 19F nuclear spin relaxation mechanism in proteins. J Mol Biol 1975; 98:121-53. [PMID: 1195374 DOI: 10.1016/s0022-2836(75)80105-7] [Citation(s) in RCA: 177] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Jonas A, Jung RW. Fluidity of the lipid phase of bovine serum high density lipoprotein from fluorescence polarization measurements. Biochem Biophys Res Commun 1975; 66:651-7. [PMID: 170927 DOI: 10.1016/0006-291x(75)90559-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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