| pertussis toxin-sensitive g proteins are transported toward synaptic terminals by fast axonal transport. | we find that half of the pertussis toxin-sensitive guanine nucleotide-binding protein (g protein) in the squid (loligo pealei) giant axon is cytoplasmic and that this species of g protein is intermediate in size between the two forms present in axolemma. this g protein is transported toward synaptic terminals at 44 mm/day. moreover, these data are consistent with there being two additional steps leading to the maturation of g proteins: (i) association with and transport on intracellular organell ... | 1991 | 1705707 |
| membrane bilayer assembly in neural tissue of rat and squid as a critical phenomenon: influence of temperature and membrane proteins. | cell membrane bilayers have been reconstructed in vitro utilizing total lipid extracts from rat neural tissue (forebrain, cerebellum, brainstem and spinal cord) and from the optic lobe and fin nerve of the squid loligo pealei. in agreement with the critical state theory of bilayer assembly (gershfeld, n.l. 1986. biophys. j. 50:457-461; gershfeld, nl.l. 1989. j. phys. chem. 93:5256-5261), these lipid extracts spontaneously formed purely unilamellar structures in aqueous dispersion, but only at a ... | 1991 | 2008012 |
| amino acid sequence of a low molecular weight, high affinity calcium-binding protein from the optic lobe of the squid loligo pealei. | the amino acid sequence was determined for squid calcium-binding protein (cabp), a low molecular weight, high affinity calcium-binding protein from squid optic lobe. the sequence shows this protein to consist of 149 amino acids with an n-acetylated n terminus. the protein has a molecular weight of 16,894 and is homologous to calmodulin, which is also present in squid optic lobe (head, j. f., spielberg, s., and kaminer, b. (1983) biochem. j. 209, 797-802). when the sequences of squid cabp and bov ... | 1989 | 2708363 |
| light-induced changes in the content of inositol phosphates in squid (loligo pealei) retina. | illumination induced an increase in inositol polyphosphates, inositol 1,4-bisphosphate and inositol 1,4,5-trisphosphate, in the photoreceptors of the squid, loligo pealei. there was a concomitant decrease in phosphatidylinositol 4,5-bisphosphate, but no light-induced change in any other phosphoinositide. none of these stimulus-induced changes were altered by treatment in vivo with pertussis toxin, which adp-ribosylated a mr-39000-peptide. these findings support the hypothesis that inositol 1,4,5 ... | 1987 | 2827625 |
| effects of palytoxin on sodium and potassium permeabilities in unmyelinated axons. | palytoxin (ptx) is a very potent marine toxin isolated from the zoanthid palythoa. its effects on the nerve membrane have been studied on two different preparations: the giant axon of the cockroach, periplaneta americana and the giant axon of the squids, loligo pealei and loligo forbesi. in both preparations, ptx at concentrations ranging from 0.03 to 10 microm depolarized the axonal membrane through a selective increase in the resting sodium conductance. this increase was never reversible and w ... | 1982 | 6123163 |
| inhibition of neurotransmitter release by c2-domain peptides implicates synaptotagmin in exocytosis. | neurotransmitter release is triggered by ca2+ ions binding to an unknown ca2+ receptor within presynaptic terminals. synaptotagmin, a ca2(+)-binding protein of synaptic and other secretory vesicles, has been proposed to mediate vesicle-plasma membrane interactions during neurotransmitter release. here we test this hypothesis using the giant synapse of the squid loligo pealei, which because of its unusually large size and well established physiology is uniquely suited for dissecting presynaptic e ... | 1993 | 8097867 |
| molecules and cognition: the latterday lessons of levels, language, and lac. evolutionary overview of brain structure and function in some vertebrates and invertebrates. | the characteristics of the nervous systems of a number of organisms in different phyla are examined at the recombinant dna, protein, neuroanatomic, neurophysiological, and cognitive levels. among the invertebrates, special attention is paid to the advantages as well as the shortcomings of the fly drosophila melanogaster, the worm caenorhabditis elegans, the honey bee apis mellifera, the sea hare aplysia californica, the octopus octopus vulgaris, and the squid loligo pealei. among vertebrates, th ... | 1993 | 8331341 |
| levels of ethanolamine intermediates in the human and rat visual system structures: comparison with neural tissues of a lower vertebrate (mustelus canis) and an invertebrate (loligo pealei). | levels of ethanolamine intermediates in the retina and optic nerves of autopsied human donors and in the rat visual system (retina, optic nerve, lateral geniculate body, superior colliculus) were measured. amounts were also obtained from the retina, optic nerve, and optic tectum of a primitive elasmobranch, the smooth dogfish mustelus canis, and from the related nervous structures (retina, optic lobe, fin nerve, and stellate ganglia) of a marine invertebrate, the squid loligo pealei. in all regi ... | 1993 | 8443564 |
| evolutionary comparison of enzyme activities of phosphatidylcholine metabolism in the nervous system of an invertebrate (loligo pealei), lower vertebrate (mustelus canis) and the rat. | while steady-state kinetic parameters (metabolite pools, km and activation energies) are partially known for the enzymes involved in phosphatidylcholine synthesis and degradation in mammalian brain, they are not available for the nervous system of lower vertebrates or invertebrates. since the extent of evolutionary development of an enzyme is not known a priori, we evaluated the kinetic and thermodynamic parameters of choline kinase, ctp:phosphocholine cytidylyltransferase, choline phosphotransf ... | 1995 | 8529026 |
| presynaptic injection of syntaxin-specific antibodies blocks transmission in the squid giant synapse. | a polyclonal antibody, raised against the squid (loligo pealei) syntaxin i, inhibited ca2+-dependent interaction of syntaxin with synaptotagmin c2a domain in vitro. presynaptic injection of the anti-loligo syntaxin igg into the squid giant synapse blocked synaptic transmission without affecting the presynaptic action potential or the voltage-gated calcium current responsible for transmitter release. repetitive presynaptic stimulation produced a gradual decrease in the amplitude of the postsynapt ... | 1998 | 9692742 |
| amino-acid sequence of squid myosin heavy chain. | this work describes the determination of the cdna sequence encoding the myosin heavy chain (mhc) of the squid, loligo pealei. to date, the amino-acid sequence of the mhc of calcium-regulated myosins is known only for two closely related species of scallops. we have determined the sequence of the entire coding region of the muscle mhc of squid, a cephalopod, and compared it with the mhc of scallops, which are pelecypods, and to other regulated and non-regulated myosins. residues present in the mh ... | 1998 | 9742454 |
| shewanella pealeana sp. nov., a member of the microbial community associated with the accessory nidamental gland of the squid loligo pealei. | a new, mesophillic, facultatively anaerobic, psychrotolerant bacterium, strain ang-sq1t (t = type strain), was isolated from a microbial community colonizing the accessory nidamental gland of the squid loligo pealei. it was selected from the community on the basis of its ability to reduce elemental sulfur. the cells are motile, gram-negative rods (2.0-3.0 microns long, 0.4-0.6 micron wide). ang-sq1t grows optimally over the temperature range of 25-30 degrees c and a ph range of 6.5-7.5 degrees c ... | 1999 | 10555311 |
| molecular evolution of the synapsin gene family. | synapsins, a family of synaptic vesicle proteins, play a crucial role in the regulation of neurotransmission and synaptogenesis. they have been identified in a variety of invertebrate and vertebrate species, including human, rat (rattus norvegicus), cow (bos taurus), longfin squid (loligo pealei), and fruit fly (drosophila melanogaster). here, synapsins were cloned from three additional species: frog (xenopus laevis), lamprey (lampetra fluviatilis), and nematode (caenorhabditis elegans). synapsi ... | 1999 | 10578110 |
| crystallization and preliminary x-ray analysis of squid neuronal sec1. | sec1 protein family members are involved in the regulation of all intracellular snare-mediated (snare = soluble n-ethylmaleimide-sensitive fusion protein attachment protein receptor) vesicle-fusion processes in a step preceding membrane fusion and have been shown to interact with t-snares. to better understand the structural basis and the role of sec1 in the regulation of the snare-complex formation, neuronal sec1 from the squid loligo pealei has been expressed and crystallized; this invertebrat ... | 2000 | 10739933 |
| retrograde axonal transport of herpes simplex virus: evidence for a single mechanism and a role for tegument. | herpes simplex virus type i (hsv) typically enters peripheral nerve terminals and then travels back along the nerve to reach the neuronal cell body, where it replicates or enters latency. to monitor axoplasmic transport of hsv, we used the giant axon of the squid, loligo pealei, a well known system for the study of axoplasmic transport. to deliver hsv into the axoplasm, viral particles stripped of their envelopes by detergent were injected into the giant axon, thereby bypassing the infective pro ... | 2000 | 10884436 |
| phylogenetic characterization of epibiotic bacteria in the accessory nidamental gland and egg capsules of the squid loligo pealei (cephalopoda:loliginidae). | sexually mature female squid loligo pealei harbour dense bacterial communities in their accessory nidamental glands (angs) and in their egg capsules (ecs). this study describes a molecular approach using the 16s rrna gene (rdna) to identify bacterial populations within the ang and the ecs of the north atlantic squid species l. pealei. fluorescent in situ hybridization (fish) and 16s rdna analysis showed that predominantly alpha- and, to a lesser extent, gamma-proteobacteria were the predominant ... | 2001 | 11321532 |
| crystal structure of the habc domain of neuronal syntaxin from the squid loligo pealei reveals conformational plasticity at its c-terminus. | intracellular membrane fusion processes are mediated by the spatial and temporal control of snare complex assembly that results in the formation of a four-helical bundle, composed of one vesicle snare and three target membrane snare polypeptide chains. syntaxins are essential t-snares and are characterized by an n-terminal habc domain, a flexible linker region, a coiled-coil or snare motif and a membrane anchor. the n-terminal habc domain fulfills important regulatory functions while the coiled- ... | 2004 | 15113421 |
| cloning and characterization of a novel g protein beta-subunit of pearl oyster (pinctada fucata), and its interaction sites with calmodulin. | a cdna clone encoding a novel g protein beta subunit of beta1 subclass, pfgbeta1 was isolated from the pearl oyster (pinctada fucata). the deduced amino acid sequence of pfgbeta1 (341 amino acids) shares high homology to northern european squid (loligo pealei) and great pond snail (lymnaea stagnalis) pfgbeta1, while it has diverged from bovine (bos taurus) and human. the well-conserved amino acid domains in g protein beta subunit, seven wd repeats, were founded in the deduced amino acid sequence ... | 2005 | 16054410 |
| crystallization and preliminary x-ray diffraction analysis of calexcitin from loligo pealei: a neuronal protein implicated in learning and memory. | the neuronal protein calexcitin from the long-finned squid loligo pealei has been expressed in escherichia coli and purified to homogeneity. calexcitin is a 22 kda calcium-binding protein that becomes up-regulated in invertebrates following pavlovian conditioning and is likely to be involved in signal transduction events associated with learning and memory. recombinant squid calexcitin has been crystallized using the hanging-drop vapour-diffusion technique in the orthorhombic space group p2(1)2( ... | 2005 | 16511184 |
| identification of highly brominated analogues of q1 in marine mammals. | three novel halogenated organic compounds (hocs) have been identified in the blubber of marine mammals from coastal new england with the molecular formulae c(9)h(3)n(2)br(6)cl, c(9)h(3)n(2)br(7), and c(9)h(4)n(2)br(5)cl. they were identified using high and low resolution gas chromatography mass spectrometry (gcms) and appear to be highly brominated analogues of q1, a heptachlorinated hoc suspected to be naturally produced. these compounds were found in atlantic white sided dolphin (lagenorhynchu ... | 2006 | 16517037 |
| squid (loligo pealei) giant fiber system: a model for studying neurodegeneration and dementia? | in many neurodegenerative disorders that lead to memory loss and dementia, the brain pathology responsible for neuronal loss is marked by accumulations of proteins in the form of extracellular plaques and intracellular filamentous tangles, containing hyperphosphorylated cytoskeletal proteins. these are assumed to arise as a consequence of deregulation of a normal pattern of topographic phosphorylation-that is, an abnormal shift of cytoskeletal protein phosphorylation from the normal axonal compa ... | 2006 | 16801505 |
| a novel 65 kda rna-binding protein in squid presynaptic terminals. | a polyclonal antibody (c4), raised against the head domain of chicken myosin va, reacted strongly towards a 65 kda polypeptide (p65) on western blots of extracts from squid optic lobes but did not recognize the heavy chain of squid myosin v. this peptide was not recognized by other myosin va antibodies, nor by an antibody specific for squid myosin v. in an attempt to identify it, p65 was purified from optic lobes of loligo plei by cationic exchange and reverse phase chromatography. several pepti ... | 2010 | 20004709 |
| levels of choline intermediates in the visual system structures and in peripheral nerve of the rat: comparison with neural tissues of a lower vertebrate (mustelus canis) and an invertebrate (loligo pealei). | the levels of choline intermediate endogenous pools in structures of the visual system (retina, optic nerve, lateral geniculate body, superior colliculus) and in sciatic nerve of adult (4-month-old) and young (30-day-old) rats were measured. the amounts were also obtained from retina, optic nerve, optic tectum and cranio-spinal nerves of a primitive elasmobranch, the smooth dogfish mustelus canis, and from related nervous structures (retina, optic lobe, fin nerve, stellar nerve and stellate gang ... | 1990 | 20504663 |
| most used codons per amino acid and per genome in the code of man compared to other organisms according to the rotating circular genetic code. | my previous theoretical research shows that the rotating circular genetic code is a viable tool to make easier to distinguish the rules of variation applied to the amino acid exchange; it presents a precise and positional bio-mathematical balance of codons, according to the amino acids they codify. here, i demonstrate that when using the conventional or classic circular genetic code, a clearer pattern for the human codon usage per amino acid and per genome emerges. the most used human codons per ... | 2011 | 22997484 |
| in vitro polymorphism and phase transitions of the neurofilamentous network isolated from the giant axon of the squid (loligo pealei l.). | using electron microscopy (em), optical diffraction and image reconstruction techniques, we have demonstrated polymorphism of neurofilamentous network (nfn) in vitro based on phase transitions of the protein assemblies. the specific polymorphic appearances depended upon a number of factors, such as k+, mg2+, ca2+ ions, as well as the charge and hydration state of the molecules. furthermore, modifications initiated by the state of phosphorylation of the sidearm proteins played an important role, ... | 2011 | 3133114 |
| preparation and characterization of two isozymes of choline acetyltransferase from squid head ganglia. ii. self-association, molecular weight determinations, and studies with inactivating antisera. | the two isozymes of choline acetyltransferase (acetyl-coa:choline o-acetyltransferase, ec 2.3.1.6) from head ganglia of loligo pealei have been examined by polyacrylamide gel electrophoresis, gel chromatography, and equilibrium sedimentation in the ultracentrifuge. inactivating antisera, prepared to both native and dithiothreitol-treated isozymes 1 and 2 of squid choline acetyltransferase, were used to demonstrate the immunologic identity of isozymes 1 and 2. each isozyme appeared to contain two ... | 2001 | 60139 |
| laser light scattering determination of size and dispersity of synaptosomes and synaptic vesicles isolated from squid (loligo pealei) optic lobes. | quasi-elastic laser light scattering has been used to investigate the size and dispersity of synaptosomes and synaptic vesicles isolated from optic lobes of the squid loligo pealei. synaptosomal fractions were highly polydisperse (mu2/gamma -2 = 0.5) and the mean diameter (-d) ranged from 0.5-2.0 microns. size distribution histograms yielded two major components - smaller particles (-d approximately 300-700 nm) and a larger group of particles (-d approximately 1,500-5,000 nm). the heterogeneity ... | 2012 | 3436312 |
| pigment migration and adaptation in the eye of the squid, loligo pealei. | the migration of the screening pigment was investigated in the retina of the intact squid. the action spectrum of pigment migration corresponds to the action spectrum of the visual pigment, rhodopsin, rather than to the absorption spectrum of the screening pigment. the total number of quanta required for a fixed criterion of pigment migration is the same, when the quanta are delivered over any period of time from 6 s to an hour or more. when less than 3-10% of the rhodopsin is isomerized, the sc ... | 2016 | 4810208 |
| primary structure of myosin from the striated adductor muscle of the atlantic scallop, pecten maximus, and expression of the regulatory domain. | we have determined the complete cdna and deduced amino acid sequences of the heavy chain, regulatory light chain and essential light chain which constitute the molecular structure of myosin from the striated adductor muscle of the scallop, pecten maximus. the deduced amino acid sequences of p. maximus regulatory light chain, essential light chain and heavy chain comprise 156, 156 and 1940 amino acids, respectively. these myosin peptide sequences, obtained from the most common of the eastern atla ... | 2000 | 11129432 |
| squid nerve sphingomyelin containing an unusual sphingoid base. | a new methodology has been developed to determine sphingolipid structures by positive-ion fast atom bombardment tandem mass spectrometry (fab-ms/ms). the method was verified by application to a structurally known glycosphingolipid, and then used in the structural study of an unusual sphingomyelin isolated from squid (loligo pealei) nerve. our previous study of this squid sphingomyelin indicated that the major base had a branched c(19) alkyl chain with three double bonds, two of which were conjug ... | 2000 | 10884294 |