Thrombin-activable fibrinolysis inhibitor (TAFI) is a carboxypeptidase B-like zymogen that activated to TAFIa by plasmin, thrombin, or the thrombin-thrombomodulin complex. The enzyme attenuates clot lysis removing lysine residues from fibrin clot. Screening of nine human cDNA libraries indicated common variation in TAFI at position 325 (Ile-325 Thr-325). This addition amino acid 147 (Ala-147 Thr-147) characterized previously. Thus, four variants having either Ala Thr and Ile were stably...

Development of inhibitors specific for heme oxygenases (HOs) should aid our understanding the HO system and facilitate future therapeutic applications. The crystal structure human HO-1 complexed with 1-(adamantan-1-yl)-2-(1H-imidazol-1-yl)ethanone (3) was determined. This inhibitor binds to distal pocket such that imidazolyl moiety coordinates iron while adamantyl group is stabilized by a hydrophobic binding pocket. Distal helix flexibility, coupled shifts in proximal residues heme, acts...

The development of heme oxygenase (HO) inhibitors, especially those that are isozyme-selective, promises powerful pharmacological tools to elucidate the regulatory characteristics HO system. It is already known has cytoprotective properties and may play a role in several disease states, making it an enticing therapeutic target. Traditionally, metalloporphyrins have been used as competitive inhibitors owing their structural similarity with substrate, heme. However, given heme's important...

A series of 1‐azolyl‐4‐phenyl‐2‐butanones was designed and synthesized for the inhibition heme oxygenases (heme oxygenase‐1 oxygenase‐2). The replacement imidazole by other azoles led to discovery novel 1 H ‐1,2,4‐triazole‐ ‐tetrazole‐based inhibitors equipotent a lead imidazole‐based inhibitor. featuring 2 ‐tetrazole or ‐1,2,3‐triazole as pharmacophore were less potent. Monosubstitution at position 4(5), identical disubstitution positions 4 5 variety electron‐withdrawing electron‐donating,...

The development of heme oxygenase (HO) inhibitors is critical in dissecting and understanding the HO system for potential therapeutic applications. We have established a program to design optimize using structure-activity relationships conjunction with X-ray crystallographic analyses. One our previous complex crystal structures revealed putative secondary hydrophobic binding pocket which could be exploited new strategy by introducing functional group that would fit into this site. To test...

Abstract Apolipoprotein(a) [apo(a)] consists of a series tandemly repeated modules known as kringles that are commonly found in many proteins involved the fibrinolytic and coagulation cascades, such plasminogen thrombin, respectively. Specifically, apo(a) contains multiple tandem repeats domains similar to kringle IV (designated KIV 1 10 ) followed by sequences V protease plasminogen. The differ with respect their ability bind lysine or analogs. represents high‐affinity lysine‐binding site...

The crystal structure of human heme oxygenase-1 (HO-1) in complex with (2R,4S)-2-[2-(4-chlorophenyl)ethyl]-2-[(1H-imidazol-1-yl)methyl]-4[((5-trifluoromethylpyridin-2-yl)thio)methyl]-1,3-dioxolane (4) reveals a novel, inducible binding mode. Inhibitor 4 coordinates the iron, its chlorophenyl group bound distal hydrophobic pocket, as seen previous structures. However, accommodation 5-trifluoromethylpyridin-2-yl requires significant shift proximal helix, inducing formation pocket. This is...

While substantial progress has been made in elucidating the roles of heme oxygenases-1 (HO-1) and -2 (HO-2) mammals, our understanding functions these enzymes health disease is still incomplete. A significant amount knowledge garnered through use nonselective inhibitors HOs, laboratory recently described more selective for HO-1. In addition, appreciation HO-1 benefitted from availability tools increasing its activity enzyme induction. By comparison, there a paucity information about HO-2...

Apolipoprotein(a) [apo(a)] shares extensive sequence similarity with plasminogen and consists of multiple tandem repeats domains similar to kringle IV (KIV), followed by homologous the KV protease domains. The apo(a) KIV can be classified into 10 types on basis amino acid (KIV1−KIV10) which KIV10 contains a canonical lysine binding site (LBS); mediates lysine-dependent interaction Lp(a) certain biological substrates. Molecular modeling studies indicated presence weak LBS in each KIV5−KIV8,...

Otoferlin, an integral membrane protein implicated in a late stage of exocytosis, has been reported to play critical role hearing although the underlying mechanisms remain elusive. However, its widespread tissue distribution infers more ubiquitous synaptic vesicle trafficking. Glutamate, excitatory neurotransmitter, is converted inhibitory counterpart, γ-aminobutyric acid (GABA), by L-glutamic decarboxylase (GAD), which exists soluble (GAD67) and membrane-bound (GAD65) forms. For first time,...

Previously, we reported that menadione activated rat, native heme oxygenase-2 (HO-2) and human recombinant selectively; it did not activate spleen, microsomal oxygenase-1. The purpose of this study was to explore some structure-activity relationships activation the idea redox properties may be an important aspect efficacy.Heme oxygenase activity determined in vitro using rat spleen brain microsomes as sources oxygenase-1 -2, respectively, well recombinant, oxygenase-2.Menadione analogs with...

Recombinant truncated forms of heme oxygenase-1 and -2 (HO-1 HO-2) were compared with their crude microsomal counterparts from brain spleen tissue adult male rats respect to inhibition by azole-based, nonporphyrin HO inhibitors. The drugs tested an imidazole-alcohol, imidazole-dioxolane, a triazole-ketone. Both the recombinant HO-2 similarly inhibited 3 drugs. form HO-1 was more susceptible than form. This difference is attributed extra amino acids in full-length enzyme. These observations...

Most bacteria possess only one heme-degrading enzyme for obtaining iron, however few such as Pseudomonas aeruginosa express two, namely PhuS and HemO. While HemO is a well-known heme oxygenase, previously we discovered that also possesses degradation activity generates verdoheme, an intermediate of breakdown. To understand the coexistence these two enzymes, using DFT calculation reveal effectively enhances through its participation in hydroxylation, rate limiting reaction. Heme converted to...

The C/EBP Homologous Protein (CHOP) is a nuclear protein that integral to the unfolded response culminating from endoplasmic reticulum stress. Previously, CHOP was shown comprise extensive disordered regions and self-associate in solution. In current study, intrinsically nature of this characterized further by comprehensive silico analyses. Using circular dichroism, differential scanning calorimetry magnetic resonance, we investigated global conformation secondary structure demonstrated, for...

Elevated plasma concentrations of lipoprotein(a) [Lp(a)] are associated with an increased risk for the development atherosclerotic disease which may be attributable to ability Lp(a) attenuate fibrinolysis. A generally accepted mechanism this effect involves direct competition plasminogen fibrin(ogen) binding sites thus reducing efficiency activation. Efforts determine domains apolipoprotein(a) [apo(a)] mediate interactions have yielded conflicting results. Thus, purpose present study was...

Carbon monoxide (CO) formed endogenously is considered to be cytoprotective, and the vast majority of CO formation attributed degradation heme by oxygenases-1 -2 (HO-1, HO-2). Previously, we observed that brain microsomes containing HO-2 produced many-fold more in presence menadione its congeners; herein explored these observations further. We determined effects various drugs on production rat recombinant human cytochrome P450 reductase (CPR); was measured gas chromatography with reductive...

A number of studies have provided evidence that lipoprotein(a) [Lp(a)] assembly is a two-step process in which initial non-covalent interactions between apolipoprotein(a) [apo(a)] and apolipoproteinB-100 (apoB-100) precede specific disulfide bond formation. We designed construct encoding apo(a) kringle IV type 9 (KIV9) the unpaired cysteine at position 67 this replaced with tyrosine. The single was expressed bacteria purified to homogeneity from cell homogenates. derivative (designated...

Reactive thiols of cysteine (cys) residues in proteins play a key role transforming chemical reactivity into biological response. The heme oxygenase-2 (HO-2) isozyme contains two cys that have been implicated binding and also the regulation its activity. In this paper, we address question for HO-2 inhibitors or activators designed our laboratory. We tested activity full length recombinant human (FL-hHO-2) analog which cys265 cys282 were both replaced by alanine to determine effect on...