The molecular basis of memory. Part 3: tagging with “emotive” neurotransmitters

Many neurons of all animals that exhibit memory (snails, worms, flies, vertebrae) present arborized shapes with many varicosities and boutons. These neurons, release neurotransmitters and contain ionotropic receptors that produce and sense electrical signals (ephaptic transmission). The extended shapes maximize neural contact with the surrounding neutrix (neural extracellular matrix (nECM)+ diffusible (neurometals and neurotransmitters) as well as with other neurons. We propose a tripartite mechanism of animal memory based on the dynamic interactions of splayed neurons with the neutrix. Their interactions form cognitive units of information (cuinfo), metal-centered complexes within the nECM around the neuron. Emotive content is provided by NTs, which embody molecular links between physiologic (body) responses and psychic feelings. We propose that neurotransmitters form mixed complexes with cuinfo used for tagging emotive memory.Thus, NTs provide encoding option not available to a Turing, binary-based, device.The neurons employ combinatorially diverse options, with > 10 NMs and > 90 NTs for encoding (flavoring) cuinfo with emotive tags. The neural network efficiently encodes, decodes and consolidates related (entangled) sets of cuinfo into a coherent pattern, the basis for emotionally imbued memory, critical for determining a behavioral choice aimed at survival. The tripartite mechanism with tagging of NTs permits of a causal connection between physiology and psychology.<br/

A peptide derived from the N-terminal region of HIV-1 Vpr promotes nuclear import in permeabilized cells: elucidation of the NLS region of the Vpr

AbstractViral protein r (Vpr), a HIV-1 auxiliary protein which mediates nuclear import of the viral preintegration complex (PIC), contains two regions, N- and C-terminal, which have been proposed to function as a nuclear localization signal (NLS). We have synthesized peptides corresponding to both regions (designated as VprN and VprC), conjugated them to bovine serum albumin (BSA), and tested their ability to mediate nuclear import in permeabilized cells. Only VprN, and not VprC, functioned as an active NLS and promoted translocation of the conjugate into nuclei. Nuclear import of the conjugate was found to be energy and temperature dependent and was inhibited by wheat germ agglutinin (WGA). However, it did not require the addition of cytosolic factors and was not inhibited by the prototypic SV40 large T-antigen NLS peptide. Our results show that Vpr harbours a non-conventional negatively charged NLS and therefore suggest that Vpr may use a distinct nuclear import pathway

The Calbindin-D28k binding site on inositol monophosphatase may allow inhibition independent of the lithium site of action

Among numerous reported biochemical effects the lithium-inhibitable enzyme inositol-monophosphatase (IMPase) remains a viable target for lithium&#x27;s therapeutic mechanism of action. Calbindin-D28k (calbindin) interacts with IMPase enhancing its activity. In the present study in silico modeling of IMPase-calbindin binding using the program MolFit indicated that the 55-66 amino acid segment of IMPase anchors calbindin via Lys59 and Lys61 with a glutamate in between (Lys-Glu-Lys motif). The model further suggested that the Lys-Glu-Lys motif interacts with residues Asp24 and Asp26 of calbindin. Indeed, we found that differently from wildtype calbindin, IMPase was not activated by mutated calbindin in which Asp24 and Asp26 were replaced by alanine. Calbindin&#x27;s effect was significantly reduced by a peptide with the sequence of amino acids 58-63 of IMPase (peptide 1) and by six amino-acid peptides including at least part of the Lys-Glu-Lys motif. The three amino-acid peptide Lys-Glu-Lys or five amino-acid peptides containing this motif were ineffective. Intracerebroventricular administration of peptide 1 resulted in a significant antidepressant-like reduced immobility in the Porsolt forced swim test (FST) compared with mice treated with a scrambled peptide or artificial cerebrospinal fluid. Based on the sequence of peptide 1, and to potentially increase the peptide&#x27;s stability, cyclic and linear pre-cyclic analog peptides were synthesized. One cyclic and one linear pre-cyclic analog peptides exhibited an inhibitory effect on calbindin-activated brain IMPase activity in vitro. These findings may lead to the development of molecules capable of inhibiting IMPase activity at an alternative site than that of lithium

Shared Epitope–Antagonistic Ligands: A New Therapeutic Strategy in Mice With Erosive Arthritis

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/112271/1/art39158.pd

Optimization of Chemical Processes by the Hydrodynamic Simulation Method (HSM)

We describe a hydrodynamic simulation method (HSM) that is based on hydrodynamic considerations in Batch and Semi Batch stirred reactor systems. The method combines hydrodynamic studies of the mixing procedure obtained from experiments in small and large scale stirred reactors together with process simulation by VisiMix software. We describe how this hydrodynamic simulation method can aid in process optimization and scale up. The use of the simulation method described in this article, will offer the user the possibility to achieve the best results during production stage, saving time and currency, and at the same time increasing the knowledge of the performed process. Several examples in the article demonstrate the benefits of the proposed method

DMAP-assisted sulfonylation as an efficient step for the methylation of primary amine motifs on solid support.

Several multistep strategies were developed to ensure single methylation of amines on solid support. These strategies rely on the introduction of the o-NBS protecting/activating group as a key step. We found that the state-of-the-art strategies fail for the methylation of several primary amine motifs, largely due to inefficient sulfonylation. Here we show that using the superior nucleophilic base DMAP instead of the commonly used base collidine as a sulfonylation additive is essential for the introduction of the o-NBS group to these amine motifs. DFT calculations provide an explanation by showing that the energy barrier of the DMAP intermediate is significantly lower than the one of the collidine. We demonstrate that using DMAP as a sole additive in the sulfonylation step results in an overall effective and regioselective N-methylation. The method presented herein proved highly efficient in solid-phase synthesis of a somatostatin analogue bearing three Nα-methylation sites that could not be synthesized using the previously described state-of-the-art methods