Amino Acids, Peptides, and Proteins Commons^™

Structural Similarity Between Β3-Peptides Synthesized From Β3-Homo-Amino Acids Or L-Aspartic Acid Monomers, Sahar Ahmed, Tara Sprules, Kamaljit Kaur

Pharmacy Faculty Articles and Research

Formation of stable secondary structures by oligomers that mimic natural peptides is a key asset for enhanced biological response. Here we show that oligomeric β³‐hexapeptides synthesized from l‐aspartic acid monomers (β³‐peptides 1, 5a, and 6) or homologated β³‐amino acids (β³‐peptide 2), fold into similar stable 14‐helical secondary structures in solution, except that the former form right‐handed 14‐helix and the later form left‐handed 14‐helix. β³‐Peptides from l‐Asp monomers contain an additional amide bond in the side chains that provides opportunities for more hydrogen bonding. However, based on the …

Analysis Of Ligand Bias In Functional Studies Involving The Allosteric Modulation Of G Protein- Coupled Receptors, Frederick J. Ehlert, Michael T. Griffin

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Introduction

The affinity constants of a ligand for active and inactive states of a receptor ultimately determine its capacity to activate downstream signaling events. In this report, we describe a reverse-engineering strategy for estimating these microscopic constants.

Methods

Our approach involves analyzing responses measured downstream in the signaling pathway of a G protein-coupled receptor under conditions of allosteric modulation and reduced receptor expression or partial receptor inactivation. The analysis also yields estimates of the isomerization constant of the unoccupied receptor, the sensitivity constant of the signaling pathway, and the more empirical parameters of the receptor population including the observed affinities …

Mechanism Underlying Ikk Activation Mediated By The Linear Ubiquitin Chain Assembly Complex (Lubac), Hiroaki Fujita, Simin Rahighi, Mariko Akita, Ryuichi Kato, Yoshiteru Sasaki, Soichi Wakatsuki, Kazuhiro Iwai

Pharmacy Faculty Articles and Research

The linear ubiquitin chain assembly complex (LUBAC) ligase, consisting of HOIL-1L, HOIP, and SHARPIN, specifically generates linear polyubiquitin chains. LUBAC-mediated linear polyubiquitination has been implicated in NF-κB activation. NEMO, a component of the IκB kinase (IKK) complex, is a substrate of LUBAC, but the precise molecular mechanism underlying linear chain-mediated NF-κB activation has not been fully elucidated. Here, we demonstrate that linearly polyubiquitinated NEMO activates IKK more potently than unanchored linear chains. In mutational analyses based on the crystal structure of the complex between the HOIP NZF1 and NEMO CC2-LZ domains, which are involved in the HOIP-NEMO interaction, NEMO mutations …

Non-Raft Ac2 Defines A Camp Signaling Compartment That Selectively Regulates Il-6 Expression In Airway Smooth Muscle Cells, Amy S. Bogard, Anna V. Birg, Rennolds S. Ostrom

Pharmacy Faculty Articles and Research

Adenylyl cyclase (AC) isoforms differ in their tissue distribution, cellular localization, regulation, and protein interactions. Most cell types express multiple AC isoforms. We hypothesized that cAMP produced by different AC isoforms regulates unique cellular responses in human bronchial smooth muscle cells (BSMC). Overexpression of AC2, AC3, or AC6 had distinct effects on forskolin (Fsk)-induced expression of a number of known cAMP-responsive genes. These data show that different AC isoforms can differentially regulate gene expression. Most notable, overexpression and activation of AC2 enhanced interleukin 6 (IL-6) expression, but overexpression of AC3 or AC6 had no effect. IL-6 production by BSMC was …

Cxcr7 Expression Disrupts Endothelial Cell Homeostasis And Causes Ligand-Dependent Invasion, Jennifer Totonchy, Lisa Clepper, Kevin G. Phillips, Owen J. T. Mccarty, Ashlee V. Moses

Pharmacy Faculty Articles and Research

The homeostatic function of endothelial cells (EC ) is critical for a number of physiological processes including vascular integrity, immunity, and wound healing. Indeed, vascular abnormalities resulting from EC dysfunction contribute to the development and spread of malignancies. The alternative SDF-1/CXCL12 receptor CXCR7 is frequently and specifically highly expressed in tumor-associated vessels. In this study, we investigate whether CXCR7 contributes to vascular dysfunction by specifically examining the effect of CXCR7 expression on EC barrier function and motility. We demonstrate that CXCR7 expression in EC results in redistribution of CD31/PECAM-1 and loss of contact inhibition. Moreover, CXCR7+ EC are deficient in …