Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: UMLS:C0851184 (
thinning
)
11,252
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We used X-ray reflectivity to investigate the structures of phospholipid multilayers with transcription-activating-factor-derived peptide (TDP) as a function of the membrane charge density. Mixed phospholipid multilayers of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dipalmitoyl -sn-glycero-
3-phosphoserine
(DPPS) with different mixing ratios (C:S) were used to elucidate the various charge densities in a plasma membrane. We fixed the peptide/lipid molar ratio (P/L) and varied the DPPC/DPPS molar ratio in the mixed multilayer. In the pure DPPC multilayer, the incorporation of TDP had nearly no effect on the bilayer thickness of the mixed lipid multilayer. However, in the mixed DPPC/DPPS multilayer, the incorporation of TDP decreased the bilayer thickness, suggesting that the TDP peptide had a stronger interaction with DPPS than with DPPC and caused disorder in the lamellar structure. Combining this with the refined X-ray reflectivity (XR) data, we concluded that the TDP existed more in the headgroup region of the TDP-induced segregated DPPS in the mixed multilayer and caused significant membrane
thinning
.
...
PMID:Phase separation of phospholipid multilayers incorporated with cell penetrating peptides. 2172 42
Sandcastle worms secrete a water-resistant proteinaceous glue that is used to bind mineral particulates into their protective tubing. Previous proteomics studies have shown that the constitutive proteins of the glue are oppositely charged co-polypeptides that form a complex coacervate precursor phase, which is critical for stable underwater delivery of the adhesive. Using ring-opening polymerization (ROP) from N-carboxyanhydride (NCA) monomers, we synthesized oppositely charged co-polypeptides that mimic the amino acid composition and molecular weight of the native glue-forming proteins. The synthesis strategy enabled the incorporation of non-standard
phosphoserine
(pSer) and 3,4-Dihydroxyphenylalanine (Dopa) amino acids in the co-polypeptides, thereby duplicating chemical functionalities of the native glue that are key for electrostatic complexation and adhesion. Complex coacervates were obtained from these oppositely charged co-polypeptides, thus mimicking the self-assembly process of the native adhesive secreted by the sandcastle worm. Varying the relative ratio of the co-polypeptides enabled the fine-tuning of coacervation conditions such as pH and ionic strength. Wetting and rheological characterization demonstrated that our oppositely charged co-polypeptide complexes exhibited the key features associated with coacervates, namely, low surface tension, shear
thinning
behaviour, and viscoelastic response, making these sandcastle worm glue-inspired polypeptide coacervates a suitable modality for water-resistant bioadhesives.
...
PMID:Complex coacervates of oppositely charged co-polypeptides inspired by the sandcastle worm glue. 3226 21
In this work, interactions between amphiphilic amino methyl coumarin and dipalmitoyl-sn-glycero-3-phosphocholine/dipalmitoyl-sn-glycero-
3-phosphoserine
(DPPC/DPPS) lipid bilayer were investigated. A combination of experimental techniques (zeta potential, fluorescence spectroscopy, and differential scanning calorimetry) along with molecular dynamics simulations was employed to examine the influence of alkyl tail length and concentration of the amphiphilic coumarin on the lipid bilayer. Alkyl tails comprising 5(C
5
), 9(C
9
), and 12(C
12
) carbon atoms were conjugated to amino methyl coumarin via a single-step process. The binding and insertion mechanisms of the amphiphilic coumarins were studied in increasing concentrations for short-tailed (C
5
) and long-tailed (C
12
) coumarins. The simulation results show that C
5
coumarin molecules penetrate the lipid bilayer, but owing to the short alkyl tail, they interact primarily with the lipid head groups resulting in lipid bilayer
thinning
; however, at high concentrations, the C
5
coumarins undergo continuous insertion-ejection from the outer leaflet of the lipid bilayer. In contrast, C
12
coumarins interact favorably with the hydrophobic lipid tails and lack the ejection-reinsertion behavior. Instead, the C
12
coumarin molecules undergo flip-flops between the outer and inner leaflets of the lipid bilayer. At high concentrations, the high-frequency flip-flops lead to lipid destabilization, causing the lipid bilayer to rupture. The simulation results are in excellent agreement with the toxicity of amphiphilic coumarin activity in cancer cells. The efficacy of amphiphilic coumarins in liposomal lipid bilayers demonstrates the promise of these molecules as a tool in the treatment of cancer.
...
PMID:Interaction of amphiphilic coumarin with DPPC/DPPS lipid bilayer: effects of concentration and alkyl tail length. 3242 May 58
