Thomas Vanaman - Academia.edu (original) (raw)

Papers by Thomas Vanaman

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

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Elsevier eBooks, 1987

Publisher Summary This chapter presents information concerning the strategies used for the prepar... more Publisher Summary This chapter presents information concerning the strategies used for the preparation and characterization of modified calmodulin derivatives useful for a variety of studies. Chemical modification is an important tool for studying calmodulin structure and function. The amino acid sequences of all but the plant calmodulins are devoid of cysteinyl residues, a common target for modification owing to the high reactivity of the nucleophilic thiol group. Modification of the calmodulin molecule with a variety of amine-directed reagents is presented. This chapter describes results of lysine modification studies using two different classes of amine-directed reagents, the nitrosoureaderived isocyanates, and several N-hydroxysuccinimide-containing compounds. Preparation of calmodulin derivatives for binding studies and immuno assays are reported using both Bolton-Hunter reagent and NHS-biotin. The exact site of modification is determined directly for the major calmodulin derivatives formed when both methyl-CCNU and NHS-biotin are reacted with calmodulin under the conditions used to produce the modifications. The simplest calmodulin-dependent enzyme to assay is 3', 5’ cyclic nucleotide phosphodiesterase (PDE). This enzyme is readily purified from bovine brain in a crude, calmodulin-stimulable state.

Journal of Molecular Biology, May 1, 1969

Bovine α-lactalbumin and hen egg-white lysozyme have closely similar amino acid sequences. A mode... more Bovine α-lactalbumin and hen egg-white lysozyme have closely similar amino acid sequences. A model of α-lactalbumin has been constructed on the basis of the main chain conformation established for lysozyme. The side chain interactions of lysozyme are listed (Table 2) and ...

ChemInform, Aug 12, 2010

Synthesis and Binding Affinity of New 1,4-Disubstituted Triazoles as Potential Dopamine D3 Recept... more Synthesis and Binding Affinity of New 1,4-Disubstituted Triazoles as Potential Dopamine D3 Receptor Ligands.-A series of new 1,4-disubstituted triazoles (V) are synthesized using click chemistry methodology and evaluated as potential ligands on several subtypes of dopamine receptors. The new compounds show high affinity for dopamine D3 receptors. Compound (Vd) displays the highest affinity at the D3 receptor, 70-fold selectivity over D 2 and 200-fold over D 4 , and behavior as a competitive antagonist in the low nanomolar range.-(INSUA, I.;

Journal of Immunology, Sep 1, 1980

The interleukin 1 gene is expressed by rat glomerular mesangial cells and is augmented in immune ... more The interleukin 1 gene is expressed by rat glomerular mesangial cells and is augmented in immune complex glomerulonephritis.

Journal of Biological Chemistry, 1992

Encyclopedia of Basic Epilepsy Research, 2009

In molecular terms, epilepsy is a dysfunction in neurotransmission, involving either an inappropr... more In molecular terms, epilepsy is a dysfunction in neurotransmission, involving either an inappropriate response to, or an altered release of, neurotransmitters (NT). We have examined the synaptosomal proteins involved in NT release to determine if alterations in their interactions correlate with epilepsy. We have quantified secretion machinery elements (SNARE – soluble N-ethylmaleimide sensitive factor attachment protein receptors) complex and SNARE effectors) in hippocampi from electrically kindled animals. In these animals, there is a persistent, asymmetric accumulation of SNARE complexes in the hippocampus ipsilateral to the stimulating electrode, regardless of stimulation site. Treatment with levetiracetam (an antiepileptic drug which specifically binds SV2 (synaptic vesicle protein 2)) dampened this accumulation and delayed kindling. Of the SNARE effectors examined, only SV2, tomosyn, and NSF (N-ethylmaleimide sensitive factor) showed alterations upon kindling. The implications of these findings toward an understanding of epilepsy are discussed.

Advances in Protein Chemistry, 1982

Federation proceedings, 1982

Numerous lines of evidence implicate calcium and calmodulin (CaM) as regulators of cell growth an... more Numerous lines of evidence implicate calcium and calmodulin (CaM) as regulators of cell growth and functional differentiation. In light of this evidence, several studies of the possible involvement of the CaM system in cellular transformation by RNA and DNA tumor viruses have been carried out. This paper summarizes the evidence linking calcium and CaM to the regulation of cell growth and critically examines the evidence that increases in CaM levels occur in transformed versus normal cells. A nontraumatic method for synchronizing both normal and transformed chick fibroblasts is presented. This method is utilized in a comparison of CaM level throughout the cell cycle of Rous sarcoma virus transformed and normal chick embryo fibroblasts. These studies best support the hypothesis that the observed differences in CaM levels between transformed and normal cultures under optimal growth conditions may largely reflect differences in the proportion of cells in a dividing versus a nondividing ...

Virology, 1973

Techniques are described for isolating several reovirus capsid polypeptides in amounts sufficient... more Techniques are described for isolating several reovirus capsid polypeptides in amounts sufficient for determination of amino and carboxyl terminal amino acid sequences and fingerprinting. Among them are chromatography on CM-and DEAE-Sephadex in the presence of urea, and gel filtration on agarose A-15 m in the presence of sodium dodecyl sulfate. Using a combination of these procedures, and starting with either virions or cores, polypeptides ~3, ~2, and ~2 have been obtained essentially pure. Polypeptides Xl and x2 have been obtained as a mixture which has so far not been resolved. All reovirus capsid polypeptides except ~2 possess blocked amino terminal amino acid residues. The amino terminal amino acid sequence of polypeptide p2 is HJX-Pro-Gly-Gly-Val-Pro-. This suggests that polypeptide ~2 is derived from its precursor, polypeptide ~1, by cleavage of the amino terminal portion of the polypeptide chain. The carboxyl terminal regions of at least three of the five major reovirus capsid polypeptides are different. Polypeptide 03 ends in-(val,val,leu)-COOH; polypeptide ~2 in-leu-(arg, tyr, tyr)-Arg-COOH; and either one or both of the two polypeptides Xl and h2 terminate(s) in-Arg-COOH, the adjacent amino acid sequence being different from that of ~2.

Respiratory Physiology & Neurobiology, 2006

This study was carried out to investigate the role of cationic charge in the hypersensitivity of ... more This study was carried out to investigate the role of cationic charge in the hypersensitivity of pulmonary C-fibers induced by airway exposure to synthetic cationic protein poly-l-lysine (PLL) in anesthetized rats. Inhalation of PLL aerosol induced a distinctly irregular breathing pattern, and significantly enhanced the pulmonary chemoreflex responses to capsaicin. However, after the cationic charges were completely removed from PLL by succinylation, the succinylated PLL no longer produced any change in either the baseline breathing pattern or the reflex responses to capsaicin. In addition, the effects of PLL were also abolished after premixing it with a polyanion, poly-l-glutamic or poly-l-aspartic acid, before delivery. In sharp contrast, when delivered within 5 min after the PLL aerosol, these two polyanions were completely ineffective in reversing the effects of PLL. Electrophysiological recording of the afferent activity of single pulmonary C-fibers further supported our conclusion that the cationic charge carried by this protein is primarily responsible for generating the stimulatory and sensitizing effects of PLL on these afferents.

Proceedings of the National Academy of Sciences, 1975

Highly purified fatty acid synthetases of chicken and rat livers have molecular weights of 500,00... more Highly purified fatty acid synthetases of chicken and rat livers have molecular weights of 500,000 and dissociate in solutions of low ionic strength into subunits of molecular weight 250,000 with loss of synthetase activity. The subunits can be reassociated in phosphate buffer with full restoration of the activity. In the presence of sodium dodecyl sulfate or guanifine-HCl, the synthetases dissociate into polypeptide chains of molecular weight 220,000 as determined by sodium dodecyl sulfate-gel electrophoresis and sedimentation equilibrium. The polypeptide contains the 4-phosphopantetheine group and the [14C]acetyl and [4C]malonyl groups if the synthetases were prelabeled with [14C]acetyl-CoA and [14C]malonyl-CoA. Similar results were obtained with the synthetase from yeast, except the subunit has a molecular weight of 200,000. These observations indicate that the multi-catalytic activities of the synthetases and the acyl carrier protein are associated only with the two polypeptide ...

Journal of Neuro-Oncology, 1994

The function of proteases in brain tumor invasion is currently not well established. For tumors o... more The function of proteases in brain tumor invasion is currently not well established. For tumors of epithelial and fibromatous origin collagenase production can enhance the invasive capacity of cells to penetrate basement membranes. We showed previously that a c-Ha-ras transformed glial cell line (CxT24neo3) invaded hamster brain tissue in vivo. These cells were also capable of invading reconstituted basement membrane and embryonic chick hearts in vitro. Since the histopathology of CxT24neo3 tumors mimics that of glioblastoma multiforme in humans, CxT24neo3 was used as the model in vitro for this type of brain tumor. Presently, we detected by zymogram analysis a gelatinase that was secreted by CxT24neo3 and that had an apparent molecular mass of 62 kD. To verify whether gelatinase affected invasion in vitro of these glial cells we determined the efficacy of a substrate specific collagenase inhibitor on invasion in vitro. GM600t is a synthetic polypeptide that specifically occupies the substrate binding sites of metalloprotease. Since this drug did not show cytotoxicity, its specificity for metalloprotease is a valuable tool to evaluate the physiological function of these enzymes on invasion. We found that treatment of CxT24neo3 with GM6001 reduced the fraction of invading CxT24neo3 cells through reconstituted basement membrane. These data suggest that metalloproteases can stimulate brain tumor invasion.

Biochimica et Biophysica Acta (BBA) - Biomembranes, 1991

Electron paramagnefic resonance was used to investigate the physical state of plant calmodulin in... more Electron paramagnefic resonance was used to investigate the physical state of plant calmodulin in solution. Wheat germ calmodulin contains a single cysteine residue (Cys-27) on the first of four calcium binding loops. In this study the nitroxide spin label 2,2,6,6-tetramethyl-4-maleimidopiperidine-l-oxyl (MAL-6) was covalentiy attached to Cys-27 to produce a CaZ+-sensitive, biologically-active, labeled protein. The rotational correlation time of the spin label, a measure of its rotational mobility and reflective of the physical state of this region of the protein, was calculated under various conditions. Relative to control, changes in the physical state of the protein reflected by increased motion of the spin label were observed at high pH, low ionic strength and upon addition of C'a z+. These results extend knowledge of the structure of the protein, previously known from solid state and biochemical studies, to ce, lmodulin in solution. inWoduction Proteins which bind Ca 2+ specifically and tightly, and which are involved in the regulation and processing of Ca 2+ flux across a cell membrane, fall into two groups, soluble proteins and membrane-intrinsic proteins. In general, Ca2+-proteins buffer the amount of calcium ion in the cytosol and regulate the activity of other effector proteins and enzymes of the cell. a, qae most prevalent and truly multifunctional (less specialized) of these Ca2+-regulatory proteins is calmodulin (CAM). This protein is found in all eukaryotic cePls, and since its discovery by Cheung [1] and Kakiuchi and Yamazaki [2] in 1970, CaM has been shown to regulate or bind more than 30 different proteins and enzymes in a calcium-dependent manner [3]. CaM is a member of the water soluble group of Ca2+-regulatory proteins and thus is found, when unbound, in the cytosol. CaM contains only calciumspecific domains (no Ca2+-Mg z+ sites) as shown by the high selectivity for Ca z+ over other physiological cations at physiological concentrations (K ÷ 0.1 M, Mg 2÷ 1-3 mM) [4,51. CaM has four of these domains which interact cooperatively allowing it to respond to rapid

FEBS Letters, 1978

Introduction Kakuichi et al. [l] and Cheung [2,3] were the first to demonstrate the presence of a... more Introduction Kakuichi et al. [l] and Cheung [2,3] were the first to demonstrate the presence of a factor in brain homogenates, which in the presence of Ca"', stimulated the activity of one of the cyclic nucleotide phosphodiesterases of this tissue. This factor was subsequently shown to be a small heat stable calcium binding protein, which was present in high concentrations in a wide variety of animal tissues [4-61. Following its purification to apparent homogeneity from bovine brain [7] and bovine heart [8] , it was noted that its physico-chemical properties were very similar to the calcium-binding subunit of rabbit skeletal muscle troponin, troponln-C, the protein which confers calcium sensitivity to actomyosin ATPase [9,10]. This idea was substantiated by the determination of the amino acid sequence of the 'calcium-dependent modulator' from bovine brain [ 1 l] and rat testis [ 121, which showed extensive homology with troponin-C, and by the finding that the 'modulator' could substitute for troponin-C in restoring calcium sensitivity to actomyosin ATPase in reconstituted systems [ 131. Troponin-C can also substitute for the 'modulator' in the activation of cyclic nucleotide

Brain and Behavior, 2017

This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Epilepsy Research, 2001

L-type voltage-sensitive Ca 2 + channels (VSCCs) preferentially modulate several neuronal process... more L-type voltage-sensitive Ca 2 + channels (VSCCs) preferentially modulate several neuronal processes that are thought to be important in epileptogenesis, including the slow afterhyperpolarization (AHP), LTP, and trophic factor gene expression. However, little is yet known about the roles of L-type VSCCs in the epileptogenic process. Here, we used cell-attached patch recording techniques and single cell mRNA analyses to study L-type VSCCs in CA1 neurons from partially dissociated (zipper) hippocampal slices from entorhinally-kindled rats. L-type Ca 2 +-channel activity was reduced by \ 50% at 1.5-3 months after kindling. Following recording, the same single neurons were extracted and collected for mRNA analysis using a recently developed method that does not amputate major dendritic processes. Therefore, neurons contained essentially full complements of mRNA. For each collected neuron, mRNA contents for the L-type pore-forming a 1D /Ca v 1.3-subunit and for calmodulin were then analyzed by semiquantitative kinetic RT-PCR. L-type a 1D-subunit mRNA was correlated with L-type Ca 2 +-channel activity across single cells, whereas calmodulin mRNA was not. Thus, these results appear to provide the first direct evidence at the single channel and gene expression levels that chronic expression of an identified Ca 2 +-channel type is modulated by epileptiform activity. Moreover, the present data suggest the hypothesis that down regulation of a 1D-gene expression by kindling may contribute to the long-term maintenance of epileptiform activity, possibly through reduced Ca 2 +-dependent AHP and/or altered expression of other relevant genes.

Biochemical and Biophysical Research Communications, 1976

Abstract Modulator protein, a brain troponin C-like protein, has been coupled to Sepharose 4B usi... more Abstract Modulator protein, a brain troponin C-like protein, has been coupled to Sepharose 4B using conditions that allow retention of phosphodiesterase stimulatory activity. This conjugate has been used to directly demonstrate the calcium dependent formation of a reversible modulator protein-phosphodiesterase complex and to purify a cyclic nucleotide phosphodiesterase by affinity chromatography.