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Haynes V, Giulivi C. Calcium-Dependent Interaction of Nitric Oxide Synthase with Cytochrome c Oxidase: Implications for Brain Bioenergetics. Brain Sci 2023; 13:1534. [PMID: 38002494 PMCID: PMC10669843 DOI: 10.3390/brainsci13111534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/24/2023] [Accepted: 10/27/2023] [Indexed: 11/26/2023] Open
Abstract
Targeted nitric oxide production is relevant for maintaining cellular energy production, protecting against oxidative stress, regulating cell death, and promoting neuroprotection. This study aimed to characterize the putative interaction of nitric-oxide synthase with mitochondrial proteins. The primary finding of this study is that cytochrome c oxidase (CCO) subunit IV (CCOIV) is associated directly with NOS in brain mitochondria when calcium ions are present. The matrix side of CCOIV binds to the N-terminus of NOS, supported by the abrogation of the binding by antibodies towards the N-terminus of NOS. Evidence supporting the interaction between CCOIV and NOS was provided by the coimmunoprecipitation of NOS from detergent-solubilized whole rat brain mitochondria with antibodies to CCOIV and the coimmunoprecipitation of CCOIV from crude brain NOS preparations using antibodies to NOS. The CCOIV domain that interacts with NOS was identified using a series of overlapping peptides derived from the primary sequence of CCOIV. As calcium ions not only activate NOS, but also facilitate the docking of NOS to CCOIV, this study points to a dynamic mechanism of controlling the bioenergetics by calcium changes, thereby adapting bioenergetics to cellular demands.
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Affiliation(s)
- Virginia Haynes
- School of Veterinary Medicine, Department Molecular Biosciences, University of California Davis, Davis, CA 95616, USA
| | - Cecilia Giulivi
- School of Veterinary Medicine, Department Molecular Biosciences, University of California Davis, Davis, CA 95616, USA
- Medical Investigation of Neurodevelopmental Disorders (MIND) Institute UCDH, University of California Davis, Sacramento, CA 95817, USA
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2
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Hemmatian Z, Keene S, Josberger E, Miyake T, Arboleda C, Soto-Rodríguez J, Baneyx F, Rolandi M. Electronic control of H + current in a bioprotonic device with Gramicidin A and Alamethicin. Nat Commun 2016; 7:12981. [PMID: 27713411 PMCID: PMC5059763 DOI: 10.1038/ncomms12981] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 08/19/2016] [Indexed: 12/04/2022] Open
Abstract
In biological systems, intercellular communication is mediated by membrane proteins and ion channels that regulate traffic of ions and small molecules across cell membranes. A bioelectronic device with ion channels that control ionic flow across a supported lipid bilayer (SLB) should therefore be ideal for interfacing with biological systems. Here, we demonstrate a biotic-abiotic bioprotonic device with Pd contacts that regulates proton (H+) flow across an SLB incorporating the ion channels Gramicidin A (gA) and Alamethicin (ALM). We model the device characteristics using the Goldman-Hodgkin-Katz (GHK) solution to the Nernst-Planck equation for transport across the membrane. We derive the permeability for an SLB integrating gA and ALM and demonstrate pH control as a function of applied voltage and membrane permeability. This work opens the door to integrating more complex H+ channels at the Pd contact interface to produce responsive biotic-abiotic devices with increased functionality.
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Affiliation(s)
- Zahra Hemmatian
- Department of Electrical Engineering, University of California Santa Cruz, Santa Cruz, California 95064, USA
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, USA
| | - Scott Keene
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, USA
| | - Erik Josberger
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, USA
- Department of Electrical Engineering, University of Washington, Seattle, Washington 98195, USA
| | - Takeo Miyake
- Department of Electrical Engineering, University of California Santa Cruz, Santa Cruz, California 95064, USA
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, USA
| | - Carina Arboleda
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, USA
| | - Jessica Soto-Rodríguez
- Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, USA
| | - François Baneyx
- Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, USA
| | - Marco Rolandi
- Department of Electrical Engineering, University of California Santa Cruz, Santa Cruz, California 95064, USA
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, USA
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3
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The peculiar N- and (-termini of trichogin GA IV are needed for membrane interaction and human cell death induction at doses lacking antibiotic activity. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:134-44. [PMID: 25306964 DOI: 10.1016/j.bbamem.2014.10.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 09/19/2014] [Accepted: 10/02/2014] [Indexed: 11/22/2022]
Abstract
Peptaibiotics, non-ribosomally synthetized peptides from various ascomycetes, are uniquely characterized by dialkylated a-amino acids, a rigid heli cal conformation, and membrane permeation properties. Although generally considered as antimicrobial peptides, peptaibiotics may display other toxicological properties, and their function is in many cases unknown. With the goal to define the biological activity and selectivity of the peptaibiotictrichogin GA IV from the human opportunist Trichodenna longibrachiatum we analyzed its membrane interaction,cytotoxic activity and antibacterial effect. Trichogin GA IV effectively killed several types of healthy and neoplastic human cells at doses (EC 50%= 4-6 ~) lacking antibiotic effects on both Gram- and Gram+ bacteria(MIC > 64 ~ ). The peptaibiotic distinctive (-terminal primary alcohol was found to cooperate with theN-terminal n-octanoyl group to permeate the membrane phospholipid bilayer and to mediate effective binding and active endocytosis of trichogin GA IV in eukaryotic cells, two steps essential for cell death induction.Replacement of one Gly with Lys plus the simultaneous esterification of the (-terminus, strongly increased trichogin GA IV anti-Gram+ activity (MIC 1-4 ~ ). but further mitigated its cytotoxicity on human cells.
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4
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Attempts toward the Synthesis of the Peptaibol Antiamoebin by Using the ‘Azirine/Oxazolone Method’. Chem Biodivers 2013; 10:920-41. [DOI: 10.1002/cbdv.201200386] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Indexed: 11/07/2022]
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5
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Reddy DN, George G, Prabhakaran EN. Crystal-Structure Analysis of cis-X-Pro-Containing Peptidomimetics: Understanding the Steric Interactions at cisX-Pro Amide Bonds. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201209517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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6
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Reddy DN, George G, Prabhakaran EN. Crystal-structure analysis of cis-X-Pro-containing peptidomimetics: understanding the steric interactions at cis X-Pro amide bonds. Angew Chem Int Ed Engl 2013; 52:3935-9. [PMID: 23450815 DOI: 10.1002/anie.201209517] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 01/18/2013] [Indexed: 11/08/2022]
Affiliation(s)
- Damodara N Reddy
- Department of Organic Chemistry, Indian Institute of Science, Bangalore, Karnataka, 560012, India
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7
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Kruglov AG, Andersson MA, Mikkola R, Roivainen M, Kredics L, Saris NEL, Salkinoja-Salonen MS. Novel mycotoxin from Acremonium exuviarum is a powerful inhibitor of the mitochondrial respiratory chain complex III. Chem Res Toxicol 2010; 22:565-73. [PMID: 19193189 DOI: 10.1021/tx800317z] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A novel mycotoxin named acrebol, consisting of two closely similar peptaibols (1726 and 1740 Da), was isolated from an indoor strain of the mitosporic ascomycete fungus Acremonium exuviarum. This paper describes the unique mitochondrial toxicity of acrebol, not earlier described for any peptaibol. Acrebol inhibited complex III of the respiratory chain of isolated rat liver mitochondria (1 mg of protein mL(-1)) with an IC(50) of approximately 80 ng mL(-1) (50 nM) after a short preincubation, and 350 ng mL(-1) caused immediate and complete inhibition. Acrebol thus is a complex III inhibitor almost as potent as antimycin A and myxothiazol but completely different in structure. Similarly to myxothiazol but in contrast to antimycin A, acrebol decreased the level of mitochondrial superoxide anion detectable by chemiluminescent probe 3,7-dihydro-2-methyl-6-(4-methoxyphenyl)imidazol[1,2-a]pyrazine-3-one. Unlike other peptaibols, acrebol in toxic concentrations did not increase the ionic and solute permeability of membranes of isolated rat liver mitochondria, did not induce disturbance of the ionic homeostasis or the osmotic balance of mitochondria, and did not release apoptogenic proteins like cytochrome c from the intermembrane space of mitochondria. In boar spermatozoa, acrebol inhibited the respiratory chain and caused ATP depletion by activation of the oligomycin-sensitive F(0)F(1)-ATPase, which resulted in the inhibition of the progressive movement. In mouse insulinoma MIN-6 cells, whose energy supply solely depends on oxidative phosphorylation, acrebol induced necrosis-like death. The pathophysiological relevance of these findings is discussed.
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Affiliation(s)
- Alexey G Kruglov
- Department of Applied Chemistry and Microbiology, University of Helsinki, P.O. Box 56, FIN-00014 Helsinki, Finland
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8
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Coppola C, Paciello A, Mangiapia G, Licen S, Boccalon M, De Napoli L, Paduano L, Tecilla P, Montesarchio D. Design, Synthesis and Characterisation of a Fluorescently Labelled CyPLOS Ionophore. Chemistry 2010; 16:13757-72. [DOI: 10.1002/chem.201000611] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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9
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Sarojini V, Balaji Rao R, Ragothama S, Balaram P. Solution conformation of a tetradecapeptide stabilized by two di-n-propyl glycine residues. J Pept Sci 2010; 16:430-6. [PMID: 20623490 DOI: 10.1002/psc.1259] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The solution conformation of a designed tetradecapeptide Boc-Val-Ala-Leu-Dpg-Val-Ala-Leu-Val-Ala-Leu-Dpg-Val-Ala-Leu-OMe (Dpg-14) containing two di-n-propyl glycine (Dpg) residues has been investigated by (1)H NMR and circular dichroism in organic solvents. The peptide aggregates formed at a concentration of 3 mM in the apolar solvent CDCl(3) were broken by the addition of 12% v/v of the more polar solvent DMSO-d(6). Successive N(i)H <--> N(i+1)H NOEs observed over the entire length of the sequence in this solvent mixture together with the observation of several characteristic medium-range NOEs support a major population of continuous helical conformations for Dpg-14. Majority of the observed coupling constants (3)JNHC(alpha)H) also support phi values in the helical conformation. Circular dichroism spectra recorded in methanol and propan-2-ol give further support in favor of helical conformation for Dpg-14 and the stability of the helix at higher temperature.
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10
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Altherr W, Linden A, Heimgartner H. The ‘Azirine/Oxazolone Method’ in Peptaibol Synthesis: Preparation of a Derivative of Trichotoxin A-50 (G). Chem Biodivers 2007; 4:1144-69. [PMID: 17589882 DOI: 10.1002/cbdv.200790102] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The synthesis of a mixture of epimeric derivatives of the peptaibol trichotoxin A-50 (G) is described. The 'azirine/oxazolone method' has been used as a superior method for the introduction of the Aib as well as the Iva units into the peptide chain. In this protocol, 2,2-disubstituted 2H-azirin-3-amines are the synthons for 2,2-disubstituted glycines, which undergo coupling with N-protected amino or peptide acids in high yield, and without any need of coupling reagents. The problem of the instability of the amide function of the Gln side chain under the conditions of the acid-catalyzed hydrolysis of Z-Gln-(Aib)(n)-N(Me)Ph was solved by using an appropriate protecting group for the amide function of the Gln side chain, e.g., the triphenylmethyl (trityl; Tr) group. The structures of two intermediate peptides, i.e., the segments comprising residues 1-5 and 10-13, resp., were established by X-ray crystallography.
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Affiliation(s)
- Werner Altherr
- Organisch-chemisches Institut der Universität Zürich, Zürich, Switzerland
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11
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Seth S, Balaram P, Mathew MK. Characterization of a 22-residue peptide derived from a designed ion channel. BIOCHIMICA ET BIOPHYSICA ACTA 1997; 1328:177-84. [PMID: 9315614 DOI: 10.1016/s0005-2736(97)00083-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We have designed a four-helix protein that is expected to tetramerize in the membrane to form an ion channel with a structurally well-defined pore. This should serve as a model system to study the structural requirements of voltage-sensitive, ion-selective transmembrane channels. We have synthesized the peptide corresponding to the channel-lining helix. Circular dichroism (CD) spectroscopy shows that this peptide is helical in the membrane. Fluorescence resonance energy transfer (FRET) shows that this peptide, at low concentrations, forms aggregates in 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine (DMPC) liposomes and facilitates ion transport across liposomal membranes. Our data indicate that a component of the designed four-helix protein, i.e., the channel-lining helix, behaves as per design.
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Affiliation(s)
- S Seth
- National Center for Biological Sciences, Indian Institute of Science Campus, Bangalore
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12
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Joseph M, Nagaraj R. Interaction of peptides corresponding to fatty acylation sites in proteins with model membranes. J Biol Chem 1995; 270:16749-55. [PMID: 7622487 DOI: 10.1074/jbc.270.28.16749] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
In recent years, a large number of proteins having covalently linked myristic and palmitic acids have been discovered. It is assumed that fatty acid acylation serves to anchor proteins to membranes. However, it is not clear whether fatty acids modulate orientation of peptide chain in membranes or help in associating hydrophilic segments of peptides with membranes. We have examined the aggregation properties and membrane association of peptides corresponding to myristoylation and palmitoylation regions of proteins by fluorescence spectroscopy. Both acylated and non-acylated peptides were used for investigation. Binding of the peptides to lipid vesicles was assessed by monitoring the fluorescence of tryptophan as well as the quenching of its fluorescence in the presence of quenchers like I- and acrylamide. Our results indicate that in the peptide corresponding to a transmembrane segment, palmitoylation results in a change in the orientation of the peptide chain in the lipid bilayer. In the case of peptides that do not have a hydrophobic segment, acylation with palmitic or myristic acid does not appear to result in increased binding to lipid bilayer. Our results suggest that (i) the primary role of myristoylation may not be an anchor for membrane attachment as assumed, (ii) palmitoylation in the case of proteins having transmembrane segments may serve to realign the transmembrane segment from the normal orientation perpendicular to the bilayer surface, (iii) in the case of proteins where there is no hydrophobic segment, palmitoylation may not serve as a membrane anchor and could be involved in interaction with other membrane-bound proteins.
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Affiliation(s)
- M Joseph
- Centre for Cellular and Molecular Biology, Hyderabad, India
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13
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Saberwal G, Nagaraj R. Interaction of hydrophobic peptides with model membranes: slow binding to membranes and not subtle variations in pore structure is responsible for the gradual release of entrapped solutes. BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1151:43-50. [PMID: 8357819 DOI: 10.1016/0005-2736(93)90069-c] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Investigation of the mechanism of action of membrane-perturbatory peptides often involves monitoring the release of entrapped solutes from small unilamellar vesicles. Complete release of vesicular contents can take 15 min or more. Theoretical calculations suggest that the process should be of the order of seconds and not minutes. We have investigated the membrane-perturbatory abilities of hydrophobic peptides corresponding to regions of pardaxin that are important for toxin action. Peptide-induced release of entrapped carboxyfluorescein (CF) from lipid vesicles under various conditions was monitored by fluorescence spectroscopy. Several minutes were required for the complete release of CF. This has been shown to be due to lack of instantaneous and complete association by all the added peptide with the lipid vesicles. In addition, for a given peptide/lipid molar ratio, an increase in lipid concentration causes an increase in the rate of CF-release. It is likely that increased binding following a greater number of collisions between peptide and vesicles is responsible for this observation. A Fast Protein Liquid Chromatography assay confirms that a significant amount of peptide remains unbound from the vesicles. Other investigators have reported the requirement for a similar time span for the complete release of vesicular contents by pardaxin and several other membrane-perturbatory peptide toxins. The proposed reason for the delay in lysis may therefore be applicable to a large variety of membrane-perturbants. Thus, the assay of peptide-induced release of vesicular contents is likely to predominantly reflect only the rate of association of peptide with the membrane, and not more subtle variations in the nature of the pore formed.
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Affiliation(s)
- G Saberwal
- Centre for Cellular and Molecular Biology, Hyderabad, India
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14
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Sitaram N, Nagaraj R. Interaction of the 47-residue antibacterial peptide seminalplasmin and its 13-residue fragment which has antibacterial and hemolytic activities with model membranes. Biochemistry 1993; 32:3124-30. [PMID: 8457573 DOI: 10.1021/bi00063a026] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The interaction of seminalplasmin (SPLN), a 47-residue antibacterial peptide, and its 13-residue fragment (SPF), which has antibacterial and hemolytic activities, with model membranes has been investigated. The fluorescence characteristics of the single Trp residue in these peptides indicate strong binding to lipid vesicles. SPLN binds more strongly to dioleoylphosphatidylglycerol vesicles compared to dioleoylphosphatidylcholine and phosphatidylserine vesicles. Localization studies using fluorescence quenchers like NO3-, I-, and acrylamide indicate that the Trp residues in both of the peptides are located away from the head group region and are associated with the hydrophobic core. Both peptides cause release of carboxyfluorescein from zwitterionic as well as anionic vesicles. The biological activities of SPLN and SPF have been rationalized in terms of lipid-peptide interactions. It is proposed that the specificity in biological activity arises due to differences in the manner in which the peptides associate with the bacterial and red blood cell surfaces.
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Affiliation(s)
- N Sitaram
- Centre for Cellular and Molecular Biology, Hyderabad, India
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15
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Chattopadhyay A, Komath SS, Raman B. Aggregation of lasalocid A in membranes: a fluorescence study. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1104:147-50. [PMID: 1550842 DOI: 10.1016/0005-2736(92)90143-a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The aggregation behavior of the carboxylic ionophore, lasalocid A, has been studied in egg phosphatidylcholine vesicles by monitoring the intrinsic fluorescence of lasalocid A. Self quenching of lasalocid A fluorescence in vesicles of egg phosphatidylcholine suggests aggregation of lasalocid A. When aggregated lasalocid A is treated with increasing concentrations of lipid, there is an increase in fluorescence due to gradual reduction of self quenching on lateral dilution. This confirms the presence of loosely held non-covalent aggregates of lasalocid A in the membrane. This result is relevant in elucidating the molecular mechanism of cation transport by lasalocid A across membranes.
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Matsuzaki K, Shioyama T, Okamura E, Umemura J, Takenaka T, Takaishi Y, Fujita T, Miyajima K. A comparative study on interactions of alpha-aminoisobutyric acid containing antibiotic peptides, trichopolyn I and hypelcin A with phosphatidylcholine bilayers. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1070:419-28. [PMID: 1764454 DOI: 10.1016/0005-2736(91)90082-j] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Interactions of alpha-aminoisobutyric acid containing antibiotic peptides, trichopolyn I and hypelcin A with phosphatidylcholine bilayers were investigated to obtain some basic information on their bioactive mechanisms. Trichopolyn I as well as hypelcin A induced the leakage of a fluorescent dye, calcein, entrapped in sonicated egg yolk L-alpha-phosphatidylcholine vesicles. A quantitative analysis revealed that both the binding affinity and the 'membrane-perturbing activity' of trichopolyn I to the vesicles are about one-third of those of hypelcin A. The conformations and the orientations of the peptide and lipid molecules in the membranes were studied using polarized Fourier transform infrared-attenuated total reflection spectroscopy, circular dichroism, and differential scanning calorimetry. In phosphatidylcholine bilayers, both peptides mainly conformed to helical structures irrespective of the membrane physical state (gel or liquid-crystalline). The helix axes, penetrating the hydrophobic region of the bilayers, were oriented neither parallel nor perpendicular to the membrane normal. The disruption in the lipid packing induced by the peptide insertion seems to be responsible for the leakage by these peptides.
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Affiliation(s)
- K Matsuzaki
- Faculty of Pharmaceutical Sciences, Kyoto University, Japan
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17
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Hypelcin A, an α-aminoisobutyric acid containing antibiotic peptide, induced fusion of egg yolk-l-α-phosphatidylcholine small unilamellar vesicles. Colloid Polym Sci 1991. [DOI: 10.1007/bf00659915] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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18
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Sitaram N, Nagaraj R. A synthetic 13-residue peptide corresponding to the hydrophobic region of bovine seminalplasmin has antibacterial activity and also causes lysis of red blood cells. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(18)86965-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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19
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Voges KP, Jung G, Sawyer WH. Depth-dependent fluorescent quenching of a tryptophan residue located at defined positions on a rigid 21-peptide helix in liposomes. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 896:64-76. [PMID: 3790588 DOI: 10.1016/0005-2736(87)90357-9] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Five lipophilic 21-peptide analogs of the potential-dependent pore-former, alamethicin, were synthesized bearing tryptophan residues at the position 1, 6, 11, 16 and 21 on a long, conformationally rigid, alpha-helix. The alpha-helical conformation was induced and stabilized using the sequential oligomers (Ala-Aib-Ala-Aib-Ala)n as analyzed by CD and NMR. The partitioning of the N-t-butoxycarbonyl 21-peptide methyl esters and the N-terminally deprotected alpha-helices was followed by fluorescence enhancement in phospholipid bilayer vesicles. Quenching experiments were performed by titrating with n-doxyl stearic acids bearing the nitroxide label at positions 5, 7, 10, 12 and 16. This well-defined system revealed that the N- and C-terminal tryptophan residues become situated in the hydrophilic region. Tryptophan at position 11 was found in the lipophilic core, whereas the tryptophan at positions 6 and 16 were localized at intermediate depths of the lipid membrane. Therefore, the helices span the lipid bilayer with their long axis normal to the membrane surface.
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20
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Das MK, Raghothama S, Balaram P. Membrane channel forming polypeptides. Molecular conformation and mitochondrial uncoupling activity of antiamoebin, an alpha-aminoisobutyric acid containing peptide. Biochemistry 1986; 25:7110-7. [PMID: 2432929 DOI: 10.1021/bi00370a053] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The conformations of the 16-residue fungal peptide antiamoebin I (Ac-Phe-Aib-Aib-Aib-D-Iva-Gly-Leu-Aib-Aib-Hyp-Gln-D-Iva-Hyp-Aib-Pro-P hol) have been investigated in dimethyl sulfoxide solution by one- and two-dimensional NMR techniques. A substantial number of resonances in the 270-MHz 1H NMR spectrum have been assigned. Intramolecularly hydrogen-bonded (solvent inaccessible) NH groups have been identified by determining solvent and temperature dependence of NH chemical shifts and rates of hydrogen-deuterium exchange. Ten backbone NH groups are inaccessible to solvent, while three NH groups assigned to the Phe(1), Aib(2), and Aib(8) residues are exposed to solvent. Interresidue nuclear Overhauser effects are consistent with psi values of approximately 120 +/- 30 degrees for Phe(1) and Leu(7). The NMR results, together with the stereochemical constraints imposed by the presence of alpha-aminoisobutyryl, isovalyl, prolyl, and 4-hydroxyprolyl residues, favor a highly ordered structure. Two backbone conformations consistent with the data are considered. Antiamoebin is shown to be an effective uncoupler of oxidative phosphorylation in rat liver mitochondria, providing evidence for its membrane-modifying activity.
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21
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Das MK, Balaram P. Interactions of the channel forming peptide alamethicin with artificial and natural membranes. J Biosci 1984. [DOI: 10.1007/bf02703892] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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22
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Calderon I, Lobos SR, Mora GC. The hemolytic effect of Salmonella typhi Ty 2 porins. EUROPEAN JOURNAL OF BIOCHEMISTRY 1984; 141:579-83. [PMID: 6086333 DOI: 10.1111/j.1432-1033.1984.tb08232.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Two outer membrane proteins of Salmonella typhi Ty 2 were extensively co-purified. According to their migration in dodecylsulfate/polyacrylamide gel electrophoresis and solubility characteristics, these proteins are homologous to the 35-kDa and 36-kDa porins found in Salmonella typhimurium. A porin homologous to the 34-kDa one has not been found in S. typhi Ty 2. A critical step in the purification of porins is heating at 100 degrees C in 2% sodium dodecyl sulfate before Sephadex gel filtration. The absence of detergent in aqueous suspensions enhances porin aggregation, these aggregations inducing human red cell lysis. Porins obtained by an alternative procedure consisting of heating at 60 degrees C instead of 100 degrees C were also hemolytic. Using nanomolar concentration of porins a strong influence of temperature on the hemolytic effect was observed. Porin-induced hemolysis was inhibited with anti-porin serum, as well as by a treatment with phenylglyoxal, which reacts with the arginine residues of proteins. The membrane-disrupting ability of porins aggregates might explain some pathogenic characteristics of gram-negative bacterial infections.
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Abstract
Peptide fragments corresponding to the signal sequence of chicken lysozyme, labelled with the fluorescent 5-dimethylaminonaphthalene-1-sulfonyl (dansyl) group have been synthesized. The emission characteristics and fluorescence polarization of the dansyl group have been used to study the interaction of signal sequence fragments with liposomes. The peptide fragments bind to liposomes and are associated with the hydrophobic core of the bilayer.
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Iqbal M, Balaram P. Aggregation of apolar peptides in organic solvents. Concentration dependence of1H-nmr parameters for peptide NH groups in 310 helical decapeptide fragment of suzukacillin. Biopolymers 1982. [DOI: 10.1002/bip.360210711] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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