Replacement of His23 by Cys in a zinc finger of HIV-1 NCp7 led to a change in 1H NMR-derived 3D structure and to a loss of biological activity

AbstractThe nucleocapsid protein NCp7 of human immunodeficiency virus type 1 (HIV-1), which is necessary for the formation of infectious virions, contains two zinc fingers of the Cys-X2-Cys-X4-His-X4-Cys form. To elucidate the importance of this particular motif, well conserved in retroviruses and retroelements, we substituted the histidine residue by a cysteine in the first zinc binding domain 13VKCFNCGKEGHTARNCRA30. The structures of the mutated and native zinc complexed peptides were studied by two-dimensional 600 MHz 1H nuclear magnetic resonance (NMR) in aqueous solution. The nuclear Overhauser effects were used as constraints to determine the solution structures using DIANA software followed by AMBER energy refinement. The results show that native and mutant peptides fold into non-identical three-dimensional structures, probably accounting for the loss of retrovirus infectivity following the His-Cys point mutation

GPCRs from fusarium graminearum detection, modeling and virtual screening - the search for new routes to control head blight disease.

201

A fast surface-matching procedure for protein-ligand docking.

Made available in DSpace on 2018-06-05T00:40:01Z (GMT). No. of bitstreams: 1 ID276921.pdf: 398378 bytes, checksum: 38e2899e85781003024b3795babfe4f3 (MD5) Previous issue date: 2006-12-2

Improving Technology Use, Digital Competence, and Access to Community Resources Among Older Participants in the University of Rhode Island Engaging Generations Cyber-Seniors digiAGE Pilot Study

This pilot study aimed to bridge the digital divide between older and younger adults. The goal was for older people in the state to become digitally literate by engaging them in a program that provides digital devices (i.e., Apple iPads), internet connectivity (i.e., through HotSpots), and training from supervised university student mentors. This project, funded as a key policy initiative through the state’s unit on aging, specifically promoted social and economic equity by targeting participants from lower-income communities and areas hit hardest by the COVID-19 pandemic. Our university partnered with senior/community centers to recruit and support English- and Spanish-speaking adults 50 years of age and older (age range: 55-100, M=72.3, SD=8.5). For this paper, we examined changes in technology use and digital competence from the pre- to the post-survey (collected over the phone) from older participants (N=145), and we examined how the program contributed to new ways for participants to connect to community resources. Based on statistical analyses, participants improved in digital competence (pre=2.06, post=2.74), technology use (pre=1.99, post=2.70), tablet use (pre=1.53, post=4.08), and the number of purposes in which participants used technology (pre=4.09, post=5.55; p’

Limit theorems for von Mises statistics of a measure preserving transformation

For a measure preserving transformation $T$ of a probability space $(X,\mathcal F,\mu)$ we investigate almost sure and distributional convergence of random variables of the form $$x \to \frac{1}{C_n} \sum_{i_1<n,...,i_d<n} f(T^{i_1}x,...,T^{i_d}x),\, n=1,2,...,$$ where $f$ (called the \emph{kernel}) is a function from $X^d$ to $\R$ and $C_1, C_2,...$ are appropriate normalizing constants. We observe that the above random variables are well defined and belong to $L_r(\mu)$ provided that the kernel is chosen from the projective tensor product $$L_p(X_1,\mathcal F_1, \mu_1) \otimes_{\pi}...\otimes_{\pi} L_p(X_d,\mathcal F_d, \mu_d)\subset L_p(\mu^d)$$ with $p=d\,r,\, r\ \in [1, \infty).$ We establish a form of the individual ergodic theorem for such sequences. Next, we give a martingale approximation argument to derive a central limit theorem in the non-degenerate case (in the sense of the classical Hoeffding's decomposition). Furthermore, for $d=2$ and a wide class of canonical kernels $f$ we also show that the convergence holds in distribution towards a quadratic form $\sum_{m=1}^{\infty} \lambda_m\eta^2_m$ in independent standard Gaussian variables $\eta_1, \eta_2,...$. Our results on the distributional convergence use a $T$--\,invariant filtration as a prerequisite and are derived from uni- and multivariate martingale approximations

Molecular, functional and structural properties of the prolyl oligopeptidase of Trypanosoma cruzi (POP Tc80), which is required for parasite entry into mammalian cells.

Made available in DSpace on 2018-06-05T00:40:50Z (GMT). No. of bitstreams: 1 ID277921.pdf: 1343722 bytes, checksum: d514a3b1ca241360a0cb8b5492056aa0 (MD5) Previous issue date: 2007-01-0

A chemosensory GPCR as a potential target to control the Root-Knot Nematode Meloidogyne incognita parasitism in plants.

Made available in DSpace on 2019-10-24T18:15:24Z (GMT). No. of bitstreams: 1 molecules2403798.pdf: 19607038 bytes, checksum: 72043c875bb4164ff917bd5eeeed827d (MD5) Previous issue date: 2019bitstream/item/203619/1/molecules-24-03798.pd

Community-wide assessment of GPCR structure modelling and ligand docking: GPCR Dock 2008

Recent breakthroughs in the determination of the crystal structures of G protein-coupled receptors (GPCRs) have provided new opportunities for structure-based drug design strategies targeting this protein family. With the aim of evaluating the current status of GPCR structure prediction and ligand docking, a community-wide, blind prediction assessment - GPCR Dock 2008 - was conducted in coordination with the publication of the crystal structure of the human adenosine A2Areceptor bound to the ligand ZM241385. Twenty-nine groups submitted 206 structural models before the release of the experimental structure, which were evaluated for the accuracy of the ligand binding mode and the overall receptor model compared with the crystal structure. This analysis highlights important aspects for success and future development, such as accurate modelling of structurally divergent regions and use of additional biochemical insight such as disulphide bridges in the extracellular loops