Computational analysis of the alpha-2 domain of apolipoprotein B - 100, a potential triggering factor in LDL aggregation.

Atherosclerosis, the major underlying cause of cardiovascular disease, is believed to arise from the accumulation of low-density lipoprotein (LDL) in the arterial subendothelial space, ultimately leading to plaque formation. It is proposed that the accumulation of LDL is linked to its intrinsic aggregation propensity. Although the native LDL is not prone to aggregation, LDL(-), an electronegative LDL characterized in the plasma, has been shown to prime LDL aggregation in a domino-like behavior similar to amyloidogenic proteins.

Effect of a SARS-CoV-2 Protein Fragment on the Amyloidogenic Propensity of Human Islet Amyloid Polypeptide.

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the onset of COVID-19 have been linked to an increased risk of developing type 2 diabetes. While a variety of mechanisms may ultimately be responsible for the onset of type 2 diabetes under these circumstances, one mechanism that has been postulated involves the increased aggregation of human islet amyloid polypeptide (hIAPP) through direct interaction with SARS-CoV-2 viral proteins. Previous computational studies investigating this possibility revealed that a nine-residue peptide fragment known as SK9 (SFYVYSRVK) from the SARS-CoV-2 envelope protein can stabilize the native conformation of hIAPP by interacting with the N-terminal region of amylin.

Key charged residues influence the amyloidogenic propensity of the helix-1 region of serum amyloid A.

Increased plasma levels of serum amyloid A (SAA), an acute-phase protein that is secreted in response to inflammation, may lead to the accumulation of amyloid in various organs thereby obstructing their functions. Severe cases can lead to a systemic disorder called AA amyloidosis. Previous studies suggest that the N-terminal helix is the most amyloidogenic region of SAA.

Revisiting the basis of the excited states for solvated fluorinated benzenes and pentafluorophenylalanine.

Vapor-phase molecular simulation studies of aromatic compounds with five or more fluorine atoms on the ring reveal emission spectra characterized by S → πσ* and πσ*→S transitions. In this study, the absorption, excitation, and solvent-dependent emission spectra of fluorinated benzenes, including pentaflurophenyalanine (F5Phe), which is a potential marker for biochemical research, were collected and compared to the results of the simulation. Time-dependent self-consistent field (TD-SCF) density functional theory (DFT) calculations were performed to examine the nature of excited states and relevant photo-physical processes.

Fatal coccidioidomycosis involving the lungs, brain, tongue, and adrenals in a cirrhotic patient. An autopsy case.

In this paper, we describe a case of fatal disseminated coccidioidomycosis (CM). The patient was a 44-year old male with a history of cirrhosis who presented with altered mental status, cough, and an enlarged, ulcerated tongue. On evaluation, the patient was found to have coccidioidal infection of the tongue, lungs, and brain.

Development of Peptide-Based Inhibitors of Amylin Aggregation Employing Aromatic and Electrostatic Repulsion.

Human islet amyloid polypeptide (hIAPP) is a 37-residue hormone that is co-stored and co-secreted with insulin. In type 2 diabetes, the polypeptide misfolds to form amyloid plaques in the pancreas. The self-assembly of hIAPP has been linked to the loss of insulin production and β-cell death.

Molecular Dynamics Simulations on the Bioactive Molecule of hIAPP22-29 (NFGAILSS) and Rational Drug Design.

This chapter includes information about the structure in equilibrium of the bioactive molecule hIAPP22-29 (NFGAILSS). The experimental structure was derived using X-ray and its 2D NOESY NMR experiments in d -DMSO and d-HFIP solvents. This molecule contains eight of the ten amino acids of the 20-29 region of the human islet amyloid polypeptide (hIAPP) often referred as the "amyloidogenic core.

Conformational Differentiation of α-Cyanohydroxycinnamic Acid Isomers: A Raman Spectroscopic Study.

Two α-cyanohydroxycinnamic acid positional isomers, α-cyano-4-hydroxycinnamic acid (CHCA4) and α-cyano-3-hydroxycinnamic acid (CHCA3), were characterized using Raman spectroscopy. We analyzed the implications of the collected Raman spectral shifts, and verified them through other spectroscopic techniques, to arrive at plausible three dimensional structures of CHCA3 and CHCA4. The positions of these groups were mapped by systematically analyzing the orientation and type of interactions functional groups make in each CHCA isomer.

Peptide Conjugates of Benzene Carboxylic Acids as Agonists and Antagonists of Amylin Aggregation.

Human islet amyloid polypeptide (hIAPP), also known as amylin, is a 37 residue peptide hormone that is stored and co-secreted with insulin. hIAPP plays a pivotal role in type 2 diabetes and is the major component of amyloid deposits found in the pancreas of patients afflicted with the disease. The self-assembly of hIAPP and the formation of amyloid is linked to the death of insulin producing β-cells.

Breast adenomyoepithelioma and adenomyoepithelioma with carcinoma (malignant adenomyoepithelioma) with associated breast malignancies: A case series emphasizing histologic, radiologic, and clinical correlation.

The 2012 World Health Organization (WHO) classification of breast tumors distinguishes adenomyoepitheliomas (AMEs) as benign tumors composed of a biphasic proliferation of phenotypically variable myoepithelial cells around small epithelial lined spaces. Many AMEs have demonstrated benign behavior and are often cured with excision with negative margins, but some have exhibited malignant transformation of the myoepithelial cells, ductal epithelial cells, or both. When one of the components is histologically malignant, it is termed AME with carcinoma.

Multivalent Peptoid Conjugates Which Overcome Enzalutamide Resistance in Prostate Cancer Cells.

Development of resistance to antiandrogens for treating advanced prostate cancer is a growing concern and extends to recently developed therapeutics, including enzalutamide. Therefore, new strategies to block androgen receptor (AR) function in prostate cancer are required. Here, we report the characterization of a multivalent conjugate presenting two bioactive ethisterone ligands arrayed as spatially defined pendant groups on a peptoid oligomer.

Crosstalk between RON and androgen receptor signaling in the development of castration resistant prostate cancer.

Castrate-resistant prostate cancer (CRPC) is the fatal form of prostate cancer. Although reactivation of androgen receptor (AR) occurs following androgen deprivation, the precise mechanism involved is unclear. Here we show that the receptor tyrosine kinase, RON alters mechanical properties of cells to influence epithelial to mesenchymal transition and functions as a transcription factor to differentially regulate AR signaling.

Spatiotemporal control of estrogen-responsive transcription in ERα-positive breast cancer cells.

Recruitment of transcription machinery to target promoters for aberrant gene expression has been well studied, but underlying control directed by distant-acting enhancers remains unclear in cancer development. Our previous study demonstrated that distant estrogen response elements (DEREs) located on chromosome 20q13 are frequently amplified and translocated to other chromosomes in ERα-positive breast cancer cells. In this study, we used three-dimensional interphase fluorescence in situ hybridization to decipher spatiotemporal gathering of multiple DEREs in the nucleus.

Aromaticity and amyloid formation: effect of π-electron distribution and aryl substituent geometry on the self-assembly of peptides derived from hIAPP(22-29).

A comprehensive investigation of peptides derived from the 22-29 region of human islet amyloid polypeptide (hIAPP) that contain phenylalanine analogs at position 23 with a variety of electron donating and withdrawing groups, along with heteroaromatic surrogates, has been employed to interrogate how π-electron distribution effects amyloid formation. Kinetic aggregation studies using turbidity measurements indicate that electron rich aromatic ring systems consistently abolish the amyloidogenic propensity of hIAPP(22-29). Electron poor systems modulate the rate of aggregation.

Evidence of π-stacking interactions in the self-assembly of hIAPP(22-29).

The role aromatic amino acids play in the formation of amyloid is a subject of controversy. In an effort to clarify the contribution of aromaticity to the self-assembly of human islet amyloid polypeptide (hIAPP)22-29 , peptide analogs containing electron donating groups (EDGs) or electron withdrawing groups (EWGs) as substituents on the aromatic ring of Phe-23 at the para position have been synthesized and characterized using turbidity measurements in conjunction with Raman and fluorescence spectroscopy. Results indicate the incorporation of EDGs on the aromatic ring of Phe-23 virtually abolish the ability of hIAPP22-29 to form amyloid.

Manufacturing high quality urinary catheters.

Forty-four percent of hospital patients with indwelling catheters can develop significant bacteriuria within 72 hours of catheterisation. It is, therefore, critical that catheters are manufactured with perfectly smooth surfaces and apertures to reduce the potential for infection. An ultrasonic cutting technology is described here that produces smooth apertures and eliminates problems associated with debris.

Using ultrasonic technology to manufacture products.

The use of ultrasonics in medical device manufacturing is gaining momentum as designers and engineers take advantage of the benefits it offers. A number of example medical applications are described that demonstrate the utility of ultrasonic processing in their manufacturer.

The power of ultrasonics.

This overview of ultrasonic technologies describes their effectiveness for a number of applications. Product examples illustrate use for welding, cutting and boring as well as atomising.

Molecular rulers: an assessment of distance and spatial relationships of Src tyrosine kinase Sh2 and active site regions.

The three-dimensional structures of the inactive conformations of Hck and Src, members of the Src protein-tyrosine kinase family, have recently been described. In both cases, the catalytic domain lies on the opposite face of the enzyme from the SH2 and SH3 domains. The active conformation of these enzymes has not yet been described.

Regulation of AMP deaminase by phosphoinositides.

AMP deaminase (AMPD) converts AMP to IMP and is a diverse and highly regulated enzyme that is a key component of the adenylate catabolic pathway. In this report, we identify the high affinity interaction between AMPD and phosphoinositides as a mechanism for regulation of this enzyme. We demonstrate that endogenous rat brain AMPD and the human AMPD3 recombinant enzymes specifically bind inositide-based affinity probes and to mixed lipid micelles that contain phosphatidylinositol 4,5-bisphosphate.

GCS1, an Arf guanosine triphosphatase-activating protein in Saccharomyces cerevisiae, is required for normal actin cytoskeletal organization in vivo and stimulates actin polymerization in vitro.

Recent cloning of a rat brain phosphatidylinositol 3,4, 5-trisphosphate binding protein, centaurin alpha, identified a novel gene family based on homology to an amino-terminal zinc-binding domain. In Saccharomyces cerevisiae, the protein with the highest homology to centaurin alpha is Gcs1p, the product of the GCS1 gene. GCS1 was originally identified as a gene conditionally required for the reentry of cells into the cell cycle after stationary phase growth.

Probing the phosphoinositide binding site of the clathrin assembly protein AP-2 with photoaffinity labels.

The relative binding specificities of the subunitsof bovine assembly protein AP-2 for the phosphatidylinositol polyphosphates (PtdInsPn) and inositol polyphosphates (InsPn) were determined by photoaffinitylabeling. Three types of benzophenone-containing photoprobes were employed: (i) the water-solubleP-1- or P-2-tethered p-benzoyldihydrocinnamoyl-InsPn (BZDC-InsPn) analogs, (ii) P-1-linked phosphotriester PtdInsPn analogs that sampled the interface between the water and lipid phases, and (iii) sn-1-O-acyl-linked PtdInsPn analogs that interacted with proteins penetrating the bilayer. The InsPn and PtdInsPn probes bind with highest selectivity and affinity to the two alpha subunit isoforms, with certain probes and conditions resulting in strong labeling of the 50-kDa mu subunit.

Specific interaction of Golgi coatomer protein alpha-COP with phosphatidylinositol 3,4,5-trisphosphate.

The phosphoinositide binding selectivity of Golgi coatomer COPI polypeptides was examined using photoaffinity analogs of the soluble inositol polyphosphates Ins(1,4,5)P3, Ins(1,3,4,5)P4, and InsP6, and of the polyphosphoinositides PtdIns(3,4,5)P3, PtdIns(4,5)P2, and PtdIns(3,4)P2. Highly selective Ins(1,3,4,5)P4-displaceable photocovalent modification of the alpha-COP subunit was observed with a p-benzoyldihydrocinnamide (BZDC)-containing probe, [3H]BZDC-Ins(1,3,4,5)P4. A more highly phosphorylated probe, [3H]BZDC-InsP6 probe labeled six of the seven subunits, with only beta, beta', delta, and epsilon-COP showing competitive displacement by excess InsP6.