Lipid-amphotericin B complex structure in solution: A possible first step in the aggregation process in cell membranes

Biochemistry ◽  
1993 ◽  
Vol 32 (15) ◽  
pp. 4139-4144 ◽  
Author(s):  
A. Rajini Balakrishnan ◽  
K. R. K. Easwaran
Keyword(s):  
Amphotericin B ◽  
Cell Membranes ◽  
Complex Structure ◽  
Aggregation Process ◽  
Lipid Amphotericin B ◽  
Structure In Solution

SAC3B is a target of CML19, the centrin 2 of Arabidopsis thaliana

2020 ◽  
Vol 477 (1) ◽  
pp. 173-189 ◽  
Author(s):  
Marco Pedretti ◽  
Carolina Conter ◽  
Paola Dominici ◽  
Alessandra Astegno
Keyword(s):  
Excision Repair ◽  
Complex Structure ◽  
Binding Motif ◽  
C Terminus ◽  
Repair Protein ◽  
Nucleotide Excision ◽  
Ef Hand ◽  
Molecular Determinants ◽  
Structure In Solution

Arabidopsis centrin 2, also known as calmodulin-like protein 19 (CML19), is a member of the EF-hand superfamily of calcium (Ca2+)-binding proteins. In addition to the notion that CML19 interacts with the nucleotide excision repair protein RAD4, CML19 was suggested to be a component of the transcription export complex 2 (TREX-2) by interacting with SAC3B. However, the molecular determinants of this interaction have remained largely unknown. Herein, we identified a CML19-binding site within the C-terminus of SAC3B and characterized the binding properties of the corresponding 26-residue peptide (SAC3Bp), which exhibits the hydrophobic triad centrin-binding motif in a reversed orientation (I8W4W1). Using a combination of spectroscopic and calorimetric experiments, we shed light on the SAC3Bp–CML19 complex structure in solution. We demonstrated that the peptide interacts not only with Ca2+-saturated CML19, but also with apo-CML19 to form a protein–peptide complex with a 1 : 1 stoichiometry. Both interactions involve hydrophobic and electrostatic contributions and include the burial of Trp residues of SAC3Bp. However, the peptide likely assumes different conformations upon binding to apo-CML19 or Ca2+-CML19. Importantly, the peptide dramatically increases the affinity for Ca2+ of CML19, especially of the C-lobe, suggesting that in vivo the protein would be Ca2+-saturated and bound to SAC3B even at resting Ca2+-levels. Our results, providing direct evidence that Arabidopsis SAC3B is a CML19 target and proposing that CML19 can bind to SAC3B through its C-lobe independent of a Ca2+ stimulus, support a functional role for these proteins in TREX-2 complex and mRNA export.

Polyamine ligands. II. Nickel(II) complexes with the tridentate ligand 5-(2'-Pyridyl)-3-azapentan-1-amine

1970 ◽  
Vol 23 (11) ◽  
pp. 2257 ◽  
Author(s):  
AT Casey ◽  
W Peters ◽  
AT Phillip
Keyword(s):  
Electronic Absorption Spectra ◽  
Complex Structure ◽  
Molar Conductance ◽  
Tridentate Ligand ◽  
Tridentate Ligands ◽  
Nickel Ion ◽  
First Order ◽  
Distorted Octahedral ◽  
Geometrical Isomerism ◽  
Structure In Solution

The tridentate amine 5-(2'-pyridyl)-3-azapentane-1-amine (pap) forms a series of stable nickel(II) complexes of the composition Ni(pap)X2 (X = Cl, Br, I, NO3, SCN, �SO4) and [Ni(pap)2]X2 (X = ClO4, I). Measurements of their electronic absorption spectra, infrared spectra, molar conductance, and magnetic susceptibility indicate that the complexes contain the amine coordinating as a tridentate ligand. In general, the Ni(pap)X2 compounds appear to possess a tetragonally distorted, octahedral structure with bridging anions in the solid state and a solvated complex structure in solution. The [Ni(pap)z]X2 compounds contain two tridentate ligands coordinated to one nickel ion, forming the octahedral NiN6 structure. Geometrical isomerism has been observed in the [Ni(pap)2]I2 compound which can be isolated as a yellow or a pink modification; this isomerism has been attributed to the alternative modes of coordination by the tridentate ligand. The isomerization of the unstable yellow form to the more stable pink form has been followed spectrophotometrically at 28� and appears to be first order in concentration.

scholarly journals Lipid Amphotericin B Formulations as Comparators in Clinical Trials

2004 ◽  
Vol 38 (2) ◽  
pp. 305-306 ◽  
Author(s):  
John H. Powers ◽  
Renata Albrecht
Keyword(s):  
Clinical Trials ◽  
Amphotericin B ◽  
Lipid Amphotericin B

Efficacious topical treatment for human cutaneous leishmaniasis with ethanolic lipid amphotericin B

2001 ◽  
Vol 95 (2) ◽  
pp. 184-186 ◽  
Author(s):  
Daniel Vardy ◽  
Yechezkel Barenholz ◽  
Natalia Naftoliev ◽  
Sidney Klaus ◽  
Leon Gilead ◽  
...  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Amphotericin B ◽  
Topical Treatment ◽  
Lipid Amphotericin B ◽  
Human Cutaneous Leishmaniasis

scholarly journals Vitamin D deficiency is a potential risk factor for lipid Amphotericin B nephrotoxicity

2019 ◽  
Vol 13 (7) ◽  
pp. e0007567
Author(s):  
Daniela Ferreira ◽  
Ana Carolina de Bragança ◽  
Rildo Aparecido Volpini ◽  
Maria Heloisa Massola Shimizu ◽  
Pedro Henrique França Gois ◽  
...  
Keyword(s):  
Vitamin D ◽  
Risk Factor ◽  
Vitamin D Deficiency ◽  
Amphotericin B ◽  
Potential Risk ◽  
Potential Risk Factor ◽  
Lipid Amphotericin B

Multicenter Evaluation of Risk Factors for Aspergillosis in Patients Treated with Lipid Amphotericin B Products: Outcomes, Drug Utilization Parameters, and Benchmarking

2003 ◽  
Vol 38 (3) ◽  
pp. 232-240 ◽  
Author(s):  
Shawn Scott Sutton ◽  
Eleanor Gomez-Fein ◽  
John Papadopoulos ◽  
Ali Olyaei ◽  
John Cazes ◽  
...  
Keyword(s):  
Risk Factors ◽  
Risk Factor ◽  
Amphotericin B ◽  
Length Of Hospital Stay ◽  
Severity Of Illness ◽  
Marrow Transplant ◽  
Drug Usage ◽  
Medical Centers ◽  
Appropriate Therapy ◽  
Lipid Amphotericin B

Purpose To evaluate the use of lipid amphotericin B products in relation to risk factors for aspergillosis and candidemia at the time therapy was initiated. Methods A single-group, concurrent, observational, multicenter study in hospitalized patients receiving a lipid amphotericin B product (Abelcet or AmBisome) was undertaken. The severity of illness, duration of therapy, length of hospital stay, microbiology, all-cause mortality, physician specialty, and clinical characteristics of each patient was recorded. Risk factors for aspergillosis and candidemia and process markers that might identify patients as candidates for lipid amphotericin B therapy were collected. Results One hundred eighty-six patients were enrolled in six US medical centers. One hundred four patients had positive fungal cultures; the majority of positive cultures were for Candida albicans (n = 40) or yeast (n = 27). Sixteen patients had positive cultures for Aspergillus. All patients receiving a lipid amphotericin B product had an overall statistically significantly greater number of risk factors for Candida vs Aspergillus infection. The mean (± SD) number of risk factors for Aspergillus was 2.46 ± 1.97 (range 0–10) and for Candida was 7.77 ± 3.14 (range 1–16) (P < 0.05). Risk factor assessment by medical service showed a statistically significantly larger number of Aspergillus risk factors in the bone marrow transplant (BMT) service compared with all other services (P < 0.05). Conclusions There were fewer documented risk factors for aspergillosis than candidemia in patients receiving a lipid amphotericin B product. Establishing drug usage protocols that include culture analysis, risk factor identification, high-risk medical services, and incorporation of drug use evaluation measures can guide the practitioner in selecting the appropriate therapy for their patients.

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