Peptides identify multiple hotspots within the ligand binding domain of the TNF receptor 2

BACKGROUND: Hotspots are defined as the minimal functional domains involved in protein:protein interactions and sufficient to induce a biological response. RESULTS: Here we describe the use of complex and high diversity phage display libraries to isolate peptides (called Hotspot Ligands or HSPLs) which sub-divide the ligand binding domain of the tumor necrosis factor receptor 2 (TNFR2; p75) into multiple hotspots. We have shown that these libraries could generate HSPLs which not only subdivide hotspots on protein and non-protein targets but act as agonists or antagonists. Using this approach, we generated peptides which were specific for human TNFR2, could be competed by the natural ligands, TNFα and TNFβ and induced an unexpected biological response in a TNFR2-specific manner. CONCLUSIONS: To our knowledge, this is the first report describing the dissection of the TNFR2 into biologically active hotspots with the concomitant identification of a novel and unexpected biological activity

A surrogate-based approach for post-genomic partner identification

BACKGROUND: Modern drug discovery is concerned with identification and validation of novel protein targets from among the 30,000 genes or more postulated to be present in the human genome. While protein-protein interactions may be central to many disease indications, it has been difficult to identify new chemical entities capable of regulating these interactions as either agonists or antagonists. RESULTS: In this paper, we show that peptide complements (or surrogates) derived from highly diverse random phage display libraries can be used for the identification of the expected natural biological partners for protein and non-protein targets. Our examples include surrogates isolated against both an extracellular secreted protein (TNFβ) and intracellular disease related mRNAs. In each case, surrogates binding to these targets were obtained and found to contain partner information embedded in their amino acid sequences. Furthermore, this information was able to identify the correct biological partners from large human genome databases by rapid and integrated computer based searches. CONCLUSIONS: Modified versions of these surrogates should provide agents capable of modifying the activity of these targets and enable one to study their involvement in specific biological processes as a means of target validation for downstream drug discovery

Characterization of an antifreeze glycopeptide gene from the Antarctic cod, Notothenia neglecta, and a functional study of the "pre-" sequence of this antifreeze glycopeptide

The antarctic fish, Notothenia neglecta, synthesizes a series of 8 different-sized antifreeze glycopeptides (AFGP 1 to 8) which lower the freezing point of its body fluids below that of sea water. I report here the sequence of one of its AFGP genes. The structural gene contains 46 tandemly repeated segments, each coding for one mature peptide. Most of the repeats (44) are composed of 51 nucleotides and encode peptides of the AFGP 8 class, but the remaining two are longer (60 nucleotides each) and code for peptides of the AFGP 7 types. Separating each repeat are three triplets that code for amino acid residues that are absent in the mature peptides. The expressed nucleotide sequence between the initiation codon and the first AFGP-coding segment is GT-rich and codes for a presumptive hydrophobic signal peptide of unusual sequence (including a long stretch of alternating cysteine and valine residues). This presumptive signal peptide can be partially cleaved in an in vitro processing system. Putative CCAAT and TATA boxes begin 102 and 92 nucleotides, respectively, upstream from the initiation codon, and the polyadenylation signal, AATAAA, is located approximately 240 nucleotides downstream from the termination codon. Thus this AFGP gene appears to encode a secreted, high-copy-number polyprotein that is processed post-translationally to produce active AFGP.U of I OnlyETDs are only available to UIUC Users without author permissio

Using Imiquimod-Induced Psoriasis-Like Skin as a Model to Measure the Skin Penetration of Anti-Psoriatic Drugs

<div><p>Objective</p><p>Psoriasis is a chronic inflammatory skin disease and topical therapy remains a key role for treatment. The aim of this study is to evaluate the influence of psoriasis-like lesions on the cutaneous permeation of anti-psoriatic drugs.</p><p>Methods</p><p>We first set up imiquimod-induced dermatitis in mice that closely resembles human psoriasis lesions. The development of the lesions is based on the IL-23/IL17A axis for phenotypical and histological characteristics. Four drugs, 5-aminolevulinic acid (ALA), tacrolimus, calcipotriol, and retinoic acid, were used to evaluate percutaneous absorption.</p><p>Results</p><p>The most hydrophilic molecule, ALA, revealed the greatest enhancement on skin absorption after imiquimod treatment. Imiquimod increased the skin deposition and flux of ALA by 5.6 to 14.4-fold, respectively, compared to normal skin. The follicular accumulation of ALA was also increased 3.8-fold. The extremely lipophilic drug retinoic acid showed a 1.7- and 3.8-fold increase in skin deposition and flux, respectively. Tacrolimus flux was enhanced from 2 to 21 μg/cm²/h by imiquimod intervention. However, imiquimod did not promote skin deposition of this macrolide. The lipophilicity, but not the molecular size, dominated drug permeation enhancement by psoriatic lesions. The in vivo percutaneous absorption of ALA and rhodamine B examined by confocal microscopy confirmed the deficient resistance of epidermal barrier for facilitating cutaneous delivery of drugs via psoriasis-like skin.</p><p>Conclusion</p><p>We established the topical delivery profiles of anti-psoriatic drugs via imiquimod-treated psoriasis-like skin.</p></div

Interface geometry of potential mega-thrust earthquakes beneath the westernmost Ryukyu subduction system

The interface geometry at the subduction boundary plays one of the most important roles on evaluation of both seismic and tsunami impacts as the mega-thrust earthquakes occur between two plates. Although the general feature of the subducted slab at the mantle depth is clearly delineated from the seismicity in the Wadati-Benioff zone, the exact interface geometry at the crustal depth is hardly obtained from abundant earthquakes scattering in and around the interface between the two plates. Examination of seismic data recorded at the dense seismic array in the Tatun volcano group of northern Taiwan shows two unambiguous P-waves generated by shallow earthquakes offshore the Hualien area in eastern Taiwan. The detailed analyses of travel-times of both P-waves show that the 1st P-wave was the direct wave propagating within the upper crust while the 2nd P-waves were reflected from the subducted slab dipping northward ~23 degrees. This observation reveals the general interface geometry between the subducted Philippine Sea and the overlaid Eurasian plates at the crustal depth, where is often considered as the locked zone and accumulated a lot of seismic energy for release. Thus, the interface geometry obtained here provides important parameters for estimating the possible rupture plane along the mega-thrust fault between two plates in the westernmost Ryukyu subduction system in the future

The comparison of skin permeation profiles of 5-aminolevulinic acid, tacrolimus, calcipotriol, and retinoic acid via control and psoriasis-like skins.

<p>^a The control group corresponds to the mice treated with the vehicle.</p><p>^b Ratio_{psoriasis/control}, ratio of the permeation parameter of psoriatic skin/ permeation parameter of control skin.</p><p>^c ―, not determined.</p><p>Each value represents the mean and S.D. (<i>n</i> = 4).</p><p>The comparison of skin permeation profiles of 5-aminolevulinic acid, tacrolimus, calcipotriol, and retinoic acid via control and psoriasis-like skins.</p

The mRNA levels of cytokines and differentiation markers in mouse skin treated with and without imiquimod cream: (A) TNF-α; (B) IL-17A; (C) IL-23; (D) filaggrin; and (E) involucrin.

<p>The control group corresponds to the mice treated with the vehicle. The data are presented as the mean of six experiments±S.D. *, <i>p</i> < 0.05 between control and imiquimod groups.</p

Cumulative percentage-time profiles of drug permeation across intact and psoriasis-like skins: (A) ALA; (B) tacrolimus; (C) calcipotriol; and (D) retinoic acid.

<p>The data of are presented as the mean of four experiments±S.D.</p

Physicochemical properties of the drug molecules tested in this study.

<p>The physicochemical properties of all drugs were obtained from DrugBank website (<a href="http://www.drugbank.ca/" target="_blank">www.drugbank.ca/</a><i>)</i>.</p><p>Physicochemical properties of the drug molecules tested in this study.</p