Marine molecular biology: an emerging field of biological sciences.

Science.gov (United States)

Thakur, Narsinh L; Jain, Roopesh; Natalio, Filipe; Hamer, Bojan; Thakur, Archana N; Müller, Werner E G

2008-01-01

An appreciation of the potential applications of molecular biology is of growing importance in many areas of life sciences, including marine biology. During the past two decades, the development of sophisticated molecular technologies and instruments for biomedical research has resulted in significant advances in the biological sciences. However, the value of molecular techniques for addressing problems in marine biology has only recently begun to be cherished. It has been proven that the exploitation of molecular biological techniques will allow difficult research questions about marine organisms and ocean processes to be addressed. Marine molecular biology is a discipline, which strives to define and solve the problems regarding the sustainable exploration of marine life for human health and welfare, through the cooperation between scientists working in marine biology, molecular biology, microbiology and chemistry disciplines. Several success stories of the applications of molecular techniques in the field of marine biology are guiding further research in this area. In this review different molecular techniques are discussed, which have application in marine microbiology, marine invertebrate biology, marine ecology, marine natural products, material sciences, fisheries, conservation and bio-invasion etc. In summary, if marine biologists and molecular biologists continue to work towards strong partnership during the next decade and recognize intellectual and technological advantages and benefits of such partnership, an exciting new frontier of marine molecular biology will emerge in the future.

Structural and Molecular Basis for Coordination in a Viral DNA Packaging Motor.

Science.gov (United States)

Mao, Huzhang; Saha, Mitul; Reyes-Aldrete, Emilio; Sherman, Michael B; Woodson, Michael; Atz, Rockney; Grimes, Shelley; Jardine, Paul J; Morais, Marc C

2016-03-01

Ring NTPases are a class of ubiquitous molecular motors involved in basic biological partitioning processes. dsDNA viruses encode ring ATPases that translocate their genomes to near-crystalline densities within pre-assembled viral capsids. Here, X-ray crystallography, cryoEM, and biochemical analyses of the dsDNA packaging motor in bacteriophage phi29 show how individual subunits are arranged in a pentameric ATPase ring and suggest how their activities are coordinated to translocate dsDNA. The resulting pseudo-atomic structure of the motor and accompanying functional analyses show how ATP is bound in the ATPase active site; identify two DNA contacts, including a potential DNA translocating loop; demonstrate that a trans-acting arginine finger is involved in coordinating hydrolysis around the ring; and suggest a functional coupling between the arginine finger and the DNA translocating loop. The ability to visualize the motor in action illuminates how the different motor components interact with each other and with their DNA substrate. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Mathematical modeling of molecular motors

OpenAIRE

Keller, Peter

2013-01-01

Amongst the many complex processes taking place in living cells, transport of cargoes across the cytosceleton is fundamental to cell viability and activity. To move cargoes between the different cell parts, cells employ Molecular Motors. The motors operate by transporting cargoes along the so-called cellular micro-tubules, namely rope-like structures that connect, for instance, the cell-nucleus and outer membrane. We introduce a new Markov Chain, the killed Quasi-Random-Walk, for such transpo...

Molecular Imaging in Synthetic Biology, and Synthetic Biology in Molecular Imaging.

Science.gov (United States)

Gilad, Assaf A; Shapiro, Mikhail G

2017-06-01

Biomedical synthetic biology is an emerging field in which cells are engineered at the genetic level to carry out novel functions with relevance to biomedical and industrial applications. This approach promises new treatments, imaging tools, and diagnostics for diseases ranging from gastrointestinal inflammatory syndromes to cancer, diabetes, and neurodegeneration. As these cellular technologies undergo pre-clinical and clinical development, it is becoming essential to monitor their location and function in vivo, necessitating appropriate molecular imaging strategies, and therefore, we have created an interest group within the World Molecular Imaging Society focusing on synthetic biology and reporter gene technologies. Here, we highlight recent advances in biomedical synthetic biology, including bacterial therapy, immunotherapy, and regenerative medicine. We then discuss emerging molecular imaging approaches to facilitate in vivo applications, focusing on reporter genes for noninvasive modalities such as magnetic resonance, ultrasound, photoacoustic imaging, bioluminescence, and radionuclear imaging. Because reporter genes can be incorporated directly into engineered genetic circuits, they are particularly well suited to imaging synthetic biological constructs, and developing them provides opportunities for creative molecular and genetic engineering.

The influence of viscosity on the functioning of molecular motors

NARCIS (Netherlands)

Klok, Martin; Janssen, Leon P.B.M.; Browne, Wesley R.; Feringa, Ben L.

2009-01-01

Light driven molecular motors based on sterically overcrowded alkenes achieve repetitive unidirectional rotation through a sequential series of photochemical and thermal steps. The influence of highly viscous environments on the functioning of unidirectional light driven molecular motors is

Correlations and symmetry of interactions influence collective dynamics of molecular motors

International Nuclear Information System (INIS)

Celis-Garza, Daniel; Teimouri, Hamid; Kolomeisky, Anatoly B

2015-01-01

Enzymatic molecules that actively support many cellular processes, including transport, cell division and cell motility, are known as motor proteins or molecular motors. Experimental studies indicate that they interact with each other and they frequently work together in large groups. To understand the mechanisms of collective behavior of motor proteins we study the effect of interactions in the transport of molecular motors along linear filaments. It is done by analyzing a recently introduced class of totally asymmetric exclusion processes that takes into account the intermolecular interactions via thermodynamically consistent approach. We develop a new theoretical method that allows us to compute analytically all dynamic properties of the system. Our analysis shows that correlations play important role in dynamics of interacting molecular motors. Surprisingly, we find that the correlations for repulsive interactions are weaker and more short-range than the correlations for the attractive interactions. In addition, it is shown that symmetry of interactions affect dynamic properties of molecular motors. The implications of these findings for motor proteins transport are discussed. Our theoretical predictions are tested by extensive Monte Carlo computer simulations. (paper)

Periodic thermodynamics of laser-driven molecular motor

International Nuclear Information System (INIS)

Li Dan; Zheng Wenwei; Wang Zhisong

2008-01-01

Operation of a laser-driven nano-motor inevitably generates a non-trivial amount of heat, which can possibly lead to instability or even hinder the motor's continual running. This work quantitatively examines the overheating problem for a recently proposed laser-operated molecular locomotive. We present a single-molecule cooling theory, in which molecular details of the locomotive system are explicitly treated. This theory is able to quantitatively predict cooling efficiency for various candidates of molecular systems for the locomotive, and also suggests concrete strategies for improving the locomotive's cooling. It is found that water environment is able to cool the hot locomotive down to room temperature within 100 picoseconds after photon absorption. This cooling time is a few orders of magnitude shorter than the typical time for laser operation, effectively preventing any overheating for the nano-locomotive. However, when the cooling is less effective in non-aqueous environment, residual heat may build up. A continuous running of the motor will then lead to a periodic thermodynamics, which is a common character of many laser-operated nano-devices

Time-dependent motor properties of multipedal molecular spiders.

Science.gov (United States)

Samii, Laleh; Blab, Gerhard A; Bromley, Elizabeth H C; Linke, Heiner; Curmi, Paul M G; Zuckermann, Martin J; Forde, Nancy R

2011-09-01

Molecular spiders are synthetic biomolecular walkers that use the asymmetry resulting from cleavage of their tracks to bias the direction of their stepping motion. Using Monte Carlo simulations that implement the Gillespie algorithm, we investigate the dependence of the biased motion of molecular spiders, along with binding time and processivity, on tunable experimental parameters, such as number of legs, span between the legs, and unbinding rate of a leg from a substrate site. We find that an increase in the number of legs increases the spiders' processivity and binding time but not their mean velocity. However, we can increase the mean velocity of spiders with simultaneous tuning of the span and the unbinding rate of a spider leg from a substrate site. To study the efficiency of molecular spiders, we introduce a time-dependent expression for the thermodynamic efficiency of a molecular motor, allowing us to account for the behavior of spider populations as a function of time. Based on this definition, we find that spiders exhibit transient motor function over time scales of many hours and have a maximum efficiency on the order of 1%, weak compared to other types of molecular motors.

Control of Surface Wettability Using Tripodal Light-Activated Molecular Motors

NARCIS (Netherlands)

Chen, Kuang-Yen; Ivashenko, Oleksii; Carroll, Gregory T.; Robertus, Jort; Kistemaker, Jos C. M.; London, Gabor; Browne, Wesley R.; Rudolf, Petra; Feringa, Ben L.

2014-01-01

Monolayers of fluorinated light-driven molecular motors were synthesized and immobilized on gold films in an altitudinal orientation via tripodal stators. In this design the fimctionalized molecular motors are not interfering and preserve their rotary function on gold. The wettability of the

Biological Soft Robotics.

Science.gov (United States)

Feinberg, Adam W

2015-01-01

In nature, nanometer-scale molecular motors are used to generate force within cells for diverse processes from transcription and transport to muscle contraction. This adaptability and scalability across wide temporal, spatial, and force regimes have spurred the development of biological soft robotic systems that seek to mimic and extend these capabilities. This review describes how molecular motors are hierarchically organized into larger-scale structures in order to provide a basic understanding of how these systems work in nature and the complexity and functionality we hope to replicate in biological soft robotics. These span the subcellular scale to macroscale, and this article focuses on the integration of biological components with synthetic materials, coupled with bioinspired robotic design. Key examples include nanoscale molecular motor-powered actuators, microscale bacteria-controlled devices, and macroscale muscle-powered robots that grasp, walk, and swim. Finally, the current challenges and future opportunities in the field are addressed.

The Molecular Biology Capstone Assessment: A Concept Assessment for Upper-Division Molecular Biology Students

Science.gov (United States)

Couch, Brian A.; Wood, William B.; Knight, Jennifer K.

2015-01-01

Measuring students' conceptual understandings has become increasingly important to biology faculty members involved in evaluating and improving departmental programs. We developed the Molecular Biology Capstone Assessment (MBCA) to gauge comprehension of fundamental concepts in molecular and cell biology and the ability to apply these concepts in…

Ultrafast Excited State Dynamics in Molecular Motors : Coupling of Motor Length to Medium Viscosity

NARCIS (Netherlands)

Conyard, Jamie; Stacko, Peter; Chen, Jiawen; McDonagh, Sophie; Hall, Christopher R.; Laptenok, Sergey P.; Browne, Wesley R.; Feringa, Ben L.; Meech, Stephen R.

2017-01-01

Photochemically driven molecular motors convert the energy of incident radiation to intramolecular rotational motion. The motor molecules considered here execute four step unidirectional rotational motion. This comprises a pair of successive light induced isomerizations to a metastable state

Energetics and efficiency of a molecular motor model

DEFF Research Database (Denmark)

C. Fogedby, Hans; Svane, Axel

2013-01-01

The energetics and efficiency of a linear molecular motor model proposed by Mogilner et al. (Phys. Lett. 237, 297 (1998)) is analyzed from an analytical point of view. The model which is based on protein friction with a track is described by coupled Langevin equations for the motion in combination...... when incorporating the full motor dynamics, owing to the strong dissipation associated with the motor action....

Structural Molecular Biology 2017 | SSRL

Science.gov (United States)

Highlights Training Workshops & Summer Schools Summer Students Structural Molecular Biology Illuminating experimental driver for structural biology research, serving the needs of a large number of academic and — Our Mission The SSRL Structural Molecular Biology program operates as an integrated resource and has

Molecular biology: Self-sustaining chemistry

Directory of Open Access Journals (Sweden)

Wrede Paul

2007-10-01

Full Text Available Abstract Molecular biology is an established interdisciplinary field within biology that deals fundamentally with the function of any nucleic acid in the cellular context. The molecular biology section in Chemistry Central Journal focusses on the genetically determined chemistry and biochemistry occuring in the cell. How can thousands of chemical reactions interact smoothly to maintain the life of cells, even in a variable environment? How is this self-sustaining system achieved? These are questions that should be answered in the light of molecular biology and evolution, but with the application of biophysical, physico-chemical, analytical and preparative technologies. As the Section Editor for the molecular biology section in Chemistry Central Journal, I hope to receive manuscripts that present new approaches aimed at better answering and shedding light upon these fascinating questions related to the chemistry of livings cells.

Marine molecular biology: An emerging field of biological sciences

Digital Repository Service at National Institute of Oceanography (India)

Thakur, N.L.; Jain, R.; Natalio, F.; Hamer, B.; Thakur, A.N.; Muller, W.E.G.

An appreciation of the potential applications of molecular biology is of growing importance in many areas of life sciences, including marine biology. During the past two decades, the development of sophisticated molecular technologies...

The Art of Building Small : From Molecular Switches to Motors (Nobel Lecture)

NARCIS (Netherlands)

Feringa, Ben L.

2017-01-01

A journey into the nano-world: The ability to design, use and control motor-like functions at the molecular level sets the stage for numerous dynamic molecular systems. In his Nobel Lecture, B. L. Feringa describes the evolution of the field of molecular motors and explains how to program and

Energetics and efficiency of a molecular motor model

International Nuclear Information System (INIS)

Fogedby, Hans C; Svane, Axel

2013-01-01

The energetics and efficiency of a linear molecular motor model proposed by Mogilner et al are analyzed from an analytical point of view. The model, which is based on protein friction with a track, is described by coupled Langevin equations for the motion in combination with coupled master equations for the ATP hydrolysis. Here the energetics and efficiency of the motor are addressed using a many body scheme with focus on the efficiency at maximum power (EMP). It is found that the EMP is reduced from about 10% in a heuristic description of the motor to about 1 per mille when incorporating the full motor dynamics, owing to the strong dissipation associated with the motor action. (paper)

Data warehousing in molecular biology.

Science.gov (United States)

Schönbach, C; Kowalski-Saunders, P; Brusic, V

2000-05-01

In the business and healthcare sectors data warehousing has provided effective solutions for information usage and knowledge discovery from databases. However, data warehousing applications in the biological research and development (R&D) sector are lagging far behind. The fuzziness and complexity of biological data represent a major challenge in data warehousing for molecular biology. By combining experiences in other domains with our findings from building a model database, we have defined the requirements for data warehousing in molecular biology.

Artificial muscle-like function from hierarchical supramolecular assembly of photoresponsive molecular motors.

Science.gov (United States)

Chen, Jiawen; Leung, Franco King-Chi; Stuart, Marc C A; Kajitani, Takashi; Fukushima, Takanori; van der Giessen, Erik; Feringa, Ben L

2018-02-01

A striking feature of living systems is their ability to produce motility by amplification of collective molecular motion from the nanoscale up to macroscopic dimensions. Some of nature's protein motors, such as myosin in muscle tissue, consist of a hierarchical supramolecular assembly of very large proteins, in which mechanical stress induces a coordinated movement. However, artificial molecular muscles have often relied on covalent polymer-based actuators. Here, we describe the macroscopic contractile muscle-like motion of a supramolecular system (comprising 95% water) formed by the hierarchical self-assembly of a photoresponsive amphiphilic molecular motor. The molecular motor first assembles into nanofibres, which further assemble into aligned bundles that make up centimetre-long strings. Irradiation induces rotary motion of the molecular motors, and propagation and accumulation of this motion lead to contraction of the fibres towards the light source. This system supports large-amplitude motion, fast response, precise control over shape, as well as weight-lifting experiments in water and air.

Artificial muscle-like function from hierarchical supramolecular assembly of photoresponsive molecular motors

Science.gov (United States)

Chen, Jiawen; Leung, Franco King-Chi; Stuart, Marc C. A.; Kajitani, Takashi; Fukushima, Takanori; van der Giessen, Erik; Feringa, Ben L.

2018-02-01

A striking feature of living systems is their ability to produce motility by amplification of collective molecular motion from the nanoscale up to macroscopic dimensions. Some of nature's protein motors, such as myosin in muscle tissue, consist of a hierarchical supramolecular assembly of very large proteins, in which mechanical stress induces a coordinated movement. However, artificial molecular muscles have often relied on covalent polymer-based actuators. Here, we describe the macroscopic contractile muscle-like motion of a supramolecular system (comprising 95% water) formed by the hierarchical self-assembly of a photoresponsive amphiphilic molecular motor. The molecular motor first assembles into nanofibres, which further assemble into aligned bundles that make up centimetre-long strings. Irradiation induces rotary motion of the molecular motors, and propagation and accumulation of this motion lead to contraction of the fibres towards the light source. This system supports large-amplitude motion, fast response, precise control over shape, as well as weight-lifting experiments in water and air.

Molecular biology - Part II: Beneficial liaisons: Radiobiology meets cellular and molecular biology

International Nuclear Information System (INIS)

Stevenson, Mary Ann; Coleman, C. Norman

1997-01-01

Purpose: The purpose of this course is to familiarize radiation oncologists with the concepts and terminology of molecular and cellular biology that are especially relevant to radiation oncology. The ability of radiation oncologists to remain current with the new discoveries of modern biology is essential to the development of improved therapeutic strategies and, importantly, to the proper balance between investment in technology and biology. Objective: This year, this Refresher Course is part of a three-part ''series'' including Drs. McKenna and Dritschilo. The objective is to provide continuing education for the academic and practicing radiation oncologist, physicist and biologist in the modern biologic concepts of cancer and its treatment. An effort will be made to relate these general concepts to the clinic by providing a broad view as to potential new biological treatments which might enhance the efficacy of radiation therapy. The specific focus of this Course will vary from year to year. Some of the classic radiation biology models which form the basis of clinical practice and laboratory research will be examined and 'newer' models will be presented which take into account the emerging knowledge of cellular and molecular biology. A few techniques in molecular and cellular biology will be described to the extent necessary to understand their basic concepts and their applicability. Aspects of radiation biology which will be covered include cell cycle, radiation-induced changes in the cellular phenotype, and considerations of the effect of the tumor microenvironment. It is not the expectation that the attendees will become experts in the particular subjects presented. Rather, it is the intent to increase their curiosity as to the new knowledge that is emerging and to demonstrate that these seemingly complicated areas can be understood and appreciated with a modicum of the effort

Molecular biology - Part II: Beneficial liaisons: Radiobiology meets cellular and molecular biology

International Nuclear Information System (INIS)

Stevenson, Mary Ann; Coleman, C. Norman

1996-01-01

Purpose: The purpose of this course is to familiarize radiation oncologists with the concepts and terminology of molecular and cellular biology that are especially relevant to radiation oncology. The ability of radiation oncologists to remain current with the new discoveries of modern biology is essential to the development of improved therapeutic strategies and, importantly, to the proper balance between investment in technology and biology. Objective: This year, this Refresher Course is part of a three-part 'series' including Drs. Martin Brown and Amato Giaccia. The objective is to provide continuing education for the academic and practicing radiation oncologist, physicist and biologist in the modern biologic concepts of cancer and its treatment. An effort will be made to relate these general concepts to the clinic by providing a broad view as to potential new biological treatments which might enhance the efficacy of radiation therapy. The specific focus of this Course will vary from year to year. Some of the classic radiation biology models which form the basis of clinical practice and laboratory research will be examined and 'newer' models will be presented which take into account the emerging knowledge of cellular and molecular biology. A few techniques in molecular and cellular biology will be described to the extent necessary to understand their basic concepts and their applicability. Aspects of radiation biology which will be covered include cell cycle, radiation-induced changes in the cellular phenotype, and considerations of the effect of the tumor microenvironment. It is not the expectation that the attendees will become experts in the particular subjects presented. Rather, it is the intent to increase their curiosity as to the new knowledge that is emerging and to demonstrate that these seemingly complicated areas can be understood and appreciated with a modicum of the effort

Introduction to basic molecular biologic techniques for molecular imaging researches

International Nuclear Information System (INIS)

Kang, Joo Hyun

2004-01-01

Molecular imaging is a rapidly growing field due to the advances in molecular biology and imaging technologies. With the introduction of imaging reporter genes into the cell, diverse cellular processes can be monitored, quantified and imaged non-invasively in vivo. These processes include the gene expression, protein-protein interactions, signal transduction pathways, and monitoring of cells such as cancer cells, immune cells, and stem cells. In the near future, molecular imaging analysis will allow us to observe the incipience and progression of the disease. These will make us easier to give a diagnosis in the early stage of intractable diseases such as cancer, neuro-degenerative disease, and immunological disorders. Additionally, molecular imaging method will be a valuable tool for the real-time evaluation of cells in molecular biology and the basic biological studies. As newer and more powerful molecular imaging tools become available, it will be necessary to corporate clinicians, molecular biologists and biochemists for the planning, interpretation, and application of these techniques to their fullest potential. In order for such a multidisciplinary team to be effective, it is essential that a common understanding of basic biochemical and molecular biologic techniques is achieved. Basic molecular techniques for molecular imaging methods are presented in this paper

Human papillomavirus molecular biology.

Science.gov (United States)

Harden, Mallory E; Munger, Karl

Human papillomaviruses are small DNA viruses with a tropism for squamous epithelia. A unique aspect of human papillomavirus molecular biology involves dependence on the differentiation status of the host epithelial cell to complete the viral lifecycle. A small group of these viruses are the etiologic agents of several types of human cancers, including oral and anogenital tract carcinomas. This review focuses on the basic molecular biology of human papillomaviruses. Copyright © 2016 Elsevier B.V. All rights reserved.

The nucleic acid revolution continues - will forensic biology become forensic molecular biology?

Science.gov (United States)

Gunn, Peter; Walsh, Simon; Roux, Claude

2014-01-01

Molecular biology has evolved far beyond that which could have been predicted at the time DNA identity testing was established. Indeed we should now perhaps be referring to "forensic molecular biology." Aside from DNA's established role in identifying the "who" in crime investigations, other developments in medical and developmental molecular biology are now ripe for application to forensic challenges. The impact of DNA methylation and other post-fertilization DNA modifications, plus the emerging role of small RNAs in the control of gene expression, is re-writing our understanding of human biology. It is apparent that these emerging technologies will expand forensic molecular biology to allow for inferences about "when" a crime took place and "what" took place. However, just as the introduction of DNA identity testing engendered many challenges, so the expansion of molecular biology into these domains will raise again the issues of scientific validity, interpretation, probative value, and infringement of personal liberties. This Commentary ponders some of these emerging issues, and presents some ideas on how they will affect the conduct of forensic molecular biology in the foreseeable future.

Biophysics of filament length regulation by molecular motors

International Nuclear Information System (INIS)

Kuan, Hui-Shun; Betterton, M D

2013-01-01

Regulating physical size is an essential problem that biological organisms must solve from the subcellular to the organismal scales, but it is not well understood what physical principles and mechanisms organisms use to sense and regulate their size. Any biophysical size-regulation scheme operates in a noisy environment and must be robust to other cellular dynamics and fluctuations. This work develops theory of filament length regulation inspired by recent experiments on kinesin-8 motor proteins, which move with directional bias on microtubule filaments and alter microtubule dynamics. Purified kinesin-8 motors can depolymerize chemically-stabilized microtubules. In the length-dependent depolymerization model, the rate of depolymerization tends to increase with filament length, because long filaments accumulate more motors at their tips and therefore shorten more quickly. When balanced with a constant filament growth rate, this mechanism can lead to a fixed polymer length. However, the mechanism by which kinesin-8 motors affect the length of dynamic microtubules in cells is less clear. We study the more biologically realistic problem of microtubule dynamic instability modulated by a motor-dependent increase in the filament catastrophe frequency. This leads to a significant decrease in the mean filament length and a narrowing of the filament length distribution. The results improve our understanding of the biophysics of length regulation in cells. (paper)

Nanotechnology Review: Molecular Electronics to Molecular Motors

Science.gov (United States)

Srivastava, Deepak; Saini, Subhash (Technical Monitor)

1998-01-01

Reviewing the status of current approaches and future projections, as already published in scientific journals and books, the talk will summarize the direction in which computational and experimental nanotechnologies are progressing. Examples of nanotechnological approaches to the concepts of design and simulation of carbon nanotube based molecular electronic and mechanical devices will be presented. The concepts of nanotube based gears and motors will be discussed. The above is a non-technical review talk which covers long term precompetitive basic research in already published material that has been presented before many US scientific meeting audiences.

Molecular ferroelectrics: where electronics meet biology.

Science.gov (United States)

Li, Jiangyu; Liu, Yuanming; Zhang, Yanhang; Cai, Hong-Ling; Xiong, Ren-Gen

2013-12-28

In the last several years, we have witnessed significant advances in molecular ferroelectrics, with the ferroelectric properties of molecular crystals approaching those of barium titanate. In addition, ferroelectricity has been observed in biological systems, filling an important missing link in bioelectric phenomena. In this perspective, we will present short historical notes on ferroelectrics, followed by an overview of the fundamentals of ferroelectricity. The latest developments in molecular ferroelectrics and biological ferroelectricity will then be highlighted, and their implications and potential applications will be discussed. We close by noting molecular ferroelectric as an exciting frontier between electronics and biology, and a number of challenges ahead are also described.

Monod and the spirit of molecular biology

OpenAIRE

Morange , Michel

2015-01-01

International audience; The founders of molecular biology shared views on the place of biology within science, as well as on the relations of molecular biology to Darwinism. Jacques Monod was no exception, but the study of his writings is particularly interesting because he expressed his point of view very clearly and pushed the implications of some of his choices further than most of his contemporaries. The spirit of molecular biology is no longer the same as in the 1960s but, interestingly,...

Stochastic mechano-chemical kinetics of molecular motors: A multidisciplinary enterprise from a physicist’s perspective

Energy Technology Data Exchange (ETDEWEB)

Chowdhury, Debashish, E-mail: debchg@gmail.com

2013-08-01

A molecular motor is made of either a single macromolecule or a macromolecular complex. Just like their macroscopic counterparts, molecular motors “transduce” input energy into mechanical work. All the nano-motors considered here operate under isothermal conditions far from equilibrium. Moreover, one of the possible mechanisms of energy transduction, called Brownian ratchet, does not even have any macroscopic counterpart. But, molecular motor is not synonymous with Brownian ratchet; a large number of molecular motors execute a noisy power stroke, rather than operating as Brownian ratchet. We review not only the structural design and stochastic kinetics of individual single motors, but also their coordination, cooperation and competition as well as the assembly of multi-module motors in various intracellular kinetic processes. Although all the motors considered here execute mechanical movements, efficiency and power output are not necessarily good measures of performance of some motors. Among the intracellular nano-motors, we consider the porters, sliders and rowers, pistons and hooks, exporters, importers, packers and movers as well as those that also synthesize, manipulate and degrade “macromolecules of life”. We review mostly the quantitative models for the kinetics of these motors. We also describe several of those motor-driven intracellular stochastic processes for which quantitative models are yet to be developed. In part I, we discuss mainly the methodology and the generic models of various important classes of molecular motors. In part II, we review many specific examples emphasizing the unity of the basic mechanisms as well as diversity of operations arising from the differences in their detailed structure and kinetics. Multi-disciplinary research is presented here from the perspective of physicists.

Controllable molecular motors engineered from myosin and RNA

Science.gov (United States)

Omabegho, Tosan; Gurel, Pinar S.; Cheng, Clarence Y.; Kim, Laura Y.; Ruijgrok, Paul V.; Das, Rhiju; Alushin, Gregory M.; Bryant, Zev

2018-01-01

Engineering biomolecular motors can provide direct tests of structure-function relationships and customized components for controlling molecular transport in artificial systems1 or in living cells2. Previously, synthetic nucleic acid motors3-5 and modified natural protein motors6-10 have been developed in separate complementary strategies to achieve tunable and controllable motor function. Integrating protein and nucleic-acid components to form engineered nucleoprotein motors may enable additional sophisticated functionalities. However, this potential has only begun to be explored in pioneering work harnessing DNA scaffolds to dictate the spacing, number and composition of tethered protein motors11-15. Here, we describe myosin motors that incorporate RNA lever arms, forming hybrid assemblies in which conformational changes in the protein motor domain are amplified and redirected by nucleic acid structures. The RNA lever arm geometry determines the speed and direction of motor transport and can be dynamically controlled using programmed transitions in the lever arm structure7,9. We have characterized the hybrid motors using in vitro motility assays, single-molecule tracking, cryo-electron microscopy and structural probing16. Our designs include nucleoprotein motors that reversibly change direction in response to oligonucleotides that drive strand-displacement17 reactions. In multimeric assemblies, the controllable motors walk processively along actin filaments at speeds of 10-20 nm s-1. Finally, to illustrate the potential for multiplexed addressable control, we demonstrate sequence-specific responses of RNA variants to oligonucleotide signals.

Molecular automata assembly: principles and simulation of bacterial membrane construction.

Science.gov (United States)

Lahoz-Beltra, R

1997-01-01

The motivation to understand the basic rules and principles governing molecular self-assembly may be relevant to explain in the context of molecular biology the self-organization and biological functions exhibited within cells. This paper presents a molecular automata model to simulate molecular self-assembly introducing the concept of molecular programming to simulate the biological function or operation performed by an assembled molecular state machine. The method is illustrated modelling Escherichia coli membrane construction including the assembly and operation of ATP synthase as well as the assembly of the bacterial flagellar motor. Flagellar motor operation was simulated using a different approach based on state machine definition used in virtual reality systems. The proposed methodology provides a modelling framework for simulation of biological functions performed by cellular components and other biological systems suitable to be modelled as molecular state machines.

Assessment of knowledge of participants on basic molecular biology techniques after 5-day intensive molecular biology training workshops in Nigeria.

Science.gov (United States)

Yisau, J I; Adagbada, A O; Bamidele, T; Fowora, M; Brai, B I C; Adebesin, O; Bamidele, M; Fesobi, T; Nwaokorie, F O; Ajayi, A; Smith, S I

2017-07-08

The deployment of molecular biology techniques for diagnosis and research in Nigeria is faced with a number of challenges, including the cost of equipment and reagents coupled with the dearth of personnel skilled in the procedures and handling of equipment. Short molecular biology training workshops were conducted at the Nigerian Institute of Medical Research (NIMR), to improve the knowledge and skills of laboratory personnel and academics in health, research, and educational facilities. Five-day molecular biology workshops were conducted annually between 2011 and 2014, with participants drawn from health, research facilities, and the academia. The courses consisted of theoretical and practical sessions. The impact of the workshops on knowledge and skill acquisition was evaluated by pre- and post-tests which consisted of 25 multiple choice and other questions. Sixty-five participants took part in the workshops. The mean knowledge of molecular biology as evaluated by the pre- and post-test assessments were 8.4 (95% CI 7.6-9.1) and 13.0 (95 CI 11.9-14.1), respectively. The mean post-test score was significantly greater than the mean pre-test score (p biology workshop significantly increased the knowledge and skills of participants in molecular biology techniques. © 2017 by The International Union of Biochemistry and Molecular Biology, 45(4):313-317, 2017. © 2017 The International Union of Biochemistry and Molecular Biology.

Assessing the Impact of Electrostatic Drag on Processive Molecular Motor Transport.

Science.gov (United States)

Smith, J Darby; McKinley, Scott A

2018-06-04

The bidirectional movement of intracellular cargo is usually described as a tug-of-war among opposite-directed families of molecular motors. While tug-of-war models have enjoyed some success, recent evidence suggests underlying motor interactions are more complex than previously understood. For example, these tug-of-war models fail to predict the counterintuitive phenomenon that inhibiting one family of motors can decrease the functionality of opposite-directed transport. In this paper, we use a stochastic differential equations modeling framework to explore one proposed physical mechanism, called microtubule tethering, that could play a role in this "co-dependence" among antagonistic motors. This hypothesis includes the possibility of a trade-off: weakly bound trailing molecular motors can serve as tethers for cargoes and processing motors, thereby enhancing motor-cargo run lengths along microtubules; however, this introduces a cost of processing at a lower mean velocity. By computing the small- and large-time mean-squared displacement of our theoretical model and comparing our results to experimental observations of dynein and its "helper protein" dynactin, we find some supporting evidence for microtubule tethering interactions. We extrapolate these findings to predict how dynein-dynactin might interact with the opposite-directed kinesin motors and introduce a criterion for when the trade-off is beneficial in simple systems.

Biasing the random walk of a molecular motor

Energy Technology Data Exchange (ETDEWEB)

Astumian, R Dean [Department of Physics, University of Maine, Orono, ME 04469-5709 (United States)

2005-11-30

Biomolecular motors are often described in mechanical terms, with analogy to cars, turbines, judo throws, levers, etc. It is important to remember however that because of their small size, and because of the aqueous environment in which molecular motors move, viscous drag and thermal noise dominate the inertial forces that drive macroscopic machines. The sequence of motions-conformational changes-by which a motor protein moves can best be described as a random walk, with transitions from one state to another occurring by thermal activation over energy barriers. In this paper I will address the question of how this random walk is biased by a non-equilibrium chemical reaction (ATP hydrolysis) so that the motor molecule moves preferentially (with almost unit certainty) in one direction, even when an external force is applied to drive it in the opposite direction. I will also discuss how these 'soft matter' motors can achieve thermodynamic efficiencies of nearly 100%.

Biasing the random walk of a molecular motor

International Nuclear Information System (INIS)

Astumian, R Dean

2005-01-01

Biomolecular motors are often described in mechanical terms, with analogy to cars, turbines, judo throws, levers, etc. It is important to remember however that because of their small size, and because of the aqueous environment in which molecular motors move, viscous drag and thermal noise dominate the inertial forces that drive macroscopic machines. The sequence of motions-conformational changes-by which a motor protein moves can best be described as a random walk, with transitions from one state to another occurring by thermal activation over energy barriers. In this paper I will address the question of how this random walk is biased by a non-equilibrium chemical reaction (ATP hydrolysis) so that the motor molecule moves preferentially (with almost unit certainty) in one direction, even when an external force is applied to drive it in the opposite direction. I will also discuss how these 'soft matter' motors can achieve thermodynamic efficiencies of nearly 100%

[Advance in molecular biology of Dendrobium (Orchidaceae)].

Science.gov (United States)

Li, Qing; Li, Biao; Guo, Shun-Xing

2016-08-01

With the development of molecular biology, the process in molecular biology research of Dendrobium is going fast. Not only did it provide new ways to identify Dendrobium quickly, reveal the genetic diversity and relationship of Dendrobium, but also lay the vital foundation for explaining the mechanism of Dendrobium growth and metabolism. The present paper reviews the recent process in molecular biology research of Dendrobium from three aspects, including molecular identification, genetic diversity and functional genes. And this review will facilitate the development of this research area and Dendrobium. Copyright© by the Chinese Pharmaceutical Association.

Adhesion of Photon-Driven Molecular Motors to Surfaces via 1,3-Dipolar Cycloadditions : Effect of Interfacial Interactions on Molecular Motion

NARCIS (Netherlands)

Carroll, Gregory T.; London, Gabor; Fernández Landaluce, Tatiana; Rudolf, Petra; Feringa, Ben L.

We report the attachment of altitudinal light-driven molecular motors to surfaces using 1,3-dipolar cycloaddition reactions. Molecular motors were designed containing azide or alkyne groups for attachment to alkyne- or azide-modified surfaces. Surface attachment was characterized by UV-vis, IR, XPS,

History of the molecular biology of cytomegaloviruses.

Science.gov (United States)

Stinski, Mark F

2014-01-01

The history of the molecular biology of cytomegaloviruses from the purification of the virus and the viral DNA to the cloning and expression of the viral genes is reviewed. A key genetic element of cytomegalovirus (the CMV promoter) contributed to our understanding of eukaryotic cell molecular biology and to the development of lifesaving therapeutic proteins. The study of the molecular biology of cytomegaloviruses also contributed to the development of antivirals to control the viral infection.

Molecular biology of the cell

CERN Document Server

Alberts, Bruce; Lewis, Julian

2000-01-01

Molecular Biology of the Cell is the classic in-dept text reference in cell biology. By extracting the fundamental concepts from this enormous and ever-growing field, the authors tell the story of cell biology, and create a coherent framework through which non-expert readers may approach the subject. Written in clear and concise language, and beautifully illustrated, the book is enjoyable to read, and it provides a clear sense of the excitement of modern biology. Molecular Biology of the Cell sets forth the current understanding of cell biology (completely updated as of Autumn 2001), and it explores the intriguing implications and possibilities of the great deal that remains unknown. The hallmark features of previous editions continue in the Fourth Edition. The book is designed with a clean and open, single-column layout. The art program maintains a completely consistent format and style, and includes over 1,600 photographs, electron micrographs, and original drawings by the authors. Clear and concise concept...

Monod and the spirit of molecular biology.

Science.gov (United States)

Morange, Michel

2015-06-01

The founders of molecular biology shared views on the place of biology within science, as well as on the relations of molecular biology to Darwinism. Jacques Monod was no exception, but the study of his writings is particularly interesting because he expressed his point of view very clearly and pushed the implications of some of his choices further than most of his contemporaries. The spirit of molecular biology is no longer the same as in the 1960s but, interestingly, Monod anticipated some recent evolutions of this discipline. Copyright © 2015 Académie des sciences. Published by Elsevier SAS. All rights reserved.

En route to surface-bound electric field-driven molecular motors.

Science.gov (United States)

Jian, Huahua; Tour, James M

2003-06-27

Four caltrop-shaped molecules that might be useful as surface-bound electric field-driven molecular motors have been synthesized. The caltrops are comprised of a pair of electron donor-acceptor arms and a tripod base. The molecular arms are based on a carbazole or oligo(phenylene ethynylene) core with a strong net dipole. The tripod base uses a silicon atom as its core. The legs of the tripod bear sulfur-tipped bonding units, as acetyl-protected benzylic thiols, for bonding to a gold surface. The geometry of the tripod base allows the caltrop to project upward from a metallic surface after self-assembly. Ellipsometric studies show that self-assembled monolayers of the caltrops are formed on Au surfaces with molecular thicknesses consistent with the desired upright-shaft arrangement. As a result, the zwitterionic molecular arms might be controllable when electric fields are applied around the caltrops, thereby constituting field-driven motors.

The molecular biology capstone assessment: a concept assessment for upper-division molecular biology students.

Science.gov (United States)

Couch, Brian A; Wood, William B; Knight, Jennifer K

2015-03-02

Measuring students' conceptual understandings has become increasingly important to biology faculty members involved in evaluating and improving departmental programs. We developed the Molecular Biology Capstone Assessment (MBCA) to gauge comprehension of fundamental concepts in molecular and cell biology and the ability to apply these concepts in novel scenarios. Targeted at graduating students, the MBCA consists of 18 multiple-true/false (T/F) questions. Each question consists of a narrative stem followed by four T/F statements, which allows a more detailed assessment of student understanding than the traditional multiple-choice format. Questions were iteratively developed with extensive faculty and student feedback, including validation through faculty reviews and response validation through student interviews. The final assessment was taken online by 504 students in upper-division courses at seven institutions. Data from this administration indicate that the MBCA has acceptable levels of internal reliability (α=0.80) and test-retest stability (r=0.93). Students achieved a wide range of scores with a 67% overall average. Performance results suggest that students have an incomplete understanding of many molecular biology concepts and continue to hold incorrect conceptions previously documented among introductory-level students. By pinpointing areas of conceptual difficulty, the MBCA can provide faculty members with guidance for improving undergraduate biology programs. © 2015 B. A. Couch et al. CBE—Life Sciences Education © 2015 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Simultaneous observation of chemomechanical coupling of a molecular motor.

Science.gov (United States)

Nishizaka, Takayuki; Hasimoto, Yuh; Masaike, Tomoko

2011-01-01

F(1)-ATPase is the smallest rotary molecular motor ever found. Unidirectional rotation of the γ-shaft is driven by precisely coordinated sequential ATP hydrolysis reactions in three catalytic sites arranged 120° apart in the cylinder. Single-molecule observation allows us to directly watch the rotation of the shaft using micron-sized plastic beads. Additionally, an advanced version of "total internal reflection fluorescence microscope (TIRFM)" enables us to detect binding and release of energy currency through fluorescently labeled ATP. In this chapter, we describe how to set up the system for simultaneous observation of these two critical events. This specialized optical setup is applicable to a variety of research, not only molecular motors but also other single-molecule topics.

The Molecular Biology of Pestiviruses.

Science.gov (United States)

Tautz, Norbert; Tews, Birke Andrea; Meyers, Gregor

2015-01-01

Pestiviruses are among the economically most important pathogens of livestock. The biology of these viruses is characterized by unique and interesting features that are both crucial for their success as pathogens and challenging from a scientific point of view. Elucidation of these features at the molecular level has made striking progress during recent years. The analyses revealed that major aspects of pestivirus biology show significant similarity to the biology of human hepatitis C virus (HCV). The detailed molecular analyses conducted for pestiviruses and HCV supported and complemented each other during the last three decades resulting in elucidation of the functions of viral proteins and RNA elements in replication and virus-host interaction. For pestiviruses, the analyses also helped to shed light on the molecular basis of persistent infection, a special strategy these viruses have evolved to be maintained within their host population. The results of these investigations are summarized in this chapter. © 2015 Elsevier Inc. All rights reserved.

Topology in Molecular Biology

CERN Document Server

Monastyrsky, Michail Ilych

2007-01-01

The book presents a class of new results in molecular biology for which topological methods and ideas are important. These include: the large-scale conformation properties of DNA; computational methods (Monte Carlo) allowing the simulation of large-scale properties of DNA; the tangle model of DNA recombination and other applications of Knot theory; dynamics of supercoiled DNA and biocatalitic properties of DNA; the structure of proteins; and other very recent problems in molecular biology. The text also provides a short course of modern topology intended for the broad audience of biologists and physicists. The authors are renowned specialists in their fields and some of the new results presented here are documented for the first time in monographic form.

Protein-polymer nano-machines. Towards synthetic control of biological processes

Directory of Open Access Journals (Sweden)

Alexander Cameron

2004-09-01

Full Text Available Abstract The exploitation of nature's machinery at length scales below the dimensions of a cell is an exciting challenge for biologists, chemists and physicists, while advances in our understanding of these biological motifs are now providing an opportunity to develop real single molecule devices for technological applications. Single molecule studies are already well advanced and biological molecular motors are being used to guide the design of nano-scale machines. However, controlling the specific functions of these devices in biological systems under changing conditions is difficult. In this review we describe the principles underlying the development of a molecular motor with numerous potential applications in nanotechnology and the use of specific synthetic polymers as prototypic molecular switches for control of the motor function. The molecular motor is a derivative of a TypeI Restriction-Modification (R-M enzyme and the synthetic polymer is drawn from the class of materials that exhibit a temperature-dependent phase transition. The potential exploitation of single molecules as functional devices has been heralded as the dawn of new era in biotechnology and medicine. It is not surprising, therefore, that the efforts of numerous multidisciplinary teams 12. have been focused in attempts to develop these systems. as machines capable of functioning at the low sub-micron and nanometre length-scales 3. However, one of the obstacles for the practical application of single molecule devices is the lack of functional control methods in biological media, under changing conditions. In this review we describe the conceptual basis for a molecular motor (a derivative of a TypeI Restriction-Modification enzyme with numerous potential applications in nanotechnology and the use of specific synthetic polymers as prototypic molecular switches for controlling the motor function 4.

Cycle kinetics, steady state thermodynamics and motors-a paradigm for living matter physics

International Nuclear Information System (INIS)

Qian, Hong

2005-01-01

An integration of the stochastic mathematical models for motor proteins with Hill's steady state thermodynamics yields a rather comprehensive theory for molecular motors as open systems in the nonequilibrium steady state. This theory, a natural extension of Gibbs' approach to isothermal molecular systems in equilibrium, is compared with other existing theories with dissipative structures and dynamics. The theory of molecular motors might be considered as an archetype for studying more complex open biological systems such as biochemical reaction networks inside living cells

Chemical and thermal modulation of molecular motor activities

Science.gov (United States)

Hong, Weili

Molecular motors of kinesin and dynein families are responsible for various intracellular activities, from long distance movement of organelles, vesicles, protein complexes, and mRNAs to powering mitotic processes. They can take nanometer steps using chemical energy from the hydrolysis of ATP (adenosine triphosphate), and their dysfunction is involved in many neurodegenerative diseases that require long distance transport of cargos. Here I report on the study of the properties of molecular motors at a single-molecule level using optical trappings. I first studied the inhibition properties of kinesin motors by marine natural compound adociasulfates. I showed that adociasulfates compete with microtubules for binding to kinesins and thus inhibit kinesins' activity. Although adociasulfates are a strong inhibitor for all kinesin members, they show a much higher inhibition effect for conventional kinesins than for mitotic kinesins. Thus adociasulfates can be used to specifically inhibit conventional kinesins. By comparing the inhibition of kinesins by two structurally similar adociasulfates, one can see that the negatively charged sulfate residue of adociasulfates can be replaced by other negative residues and thus make it possible for adociasulfate-derived compounds to be more cell permeable. Kinesins and dyneins move cargos towards opposite directions along a microtubule. Cargos with both kinesins and dyneins attached often move bidirectionally due to undergoing a tug-of-war between the oppositely moving kinesin and dynein motors. Here I studied the effect of temperature on microtubule-based kinesin and dynein motor transport. While kinesins' and dyneins' velocities are closely matched above 15 °C, below this temperature the dyneins' velocity decreases much faster than the kinesins'. The kinesins' and dyneins' forces do not measurably change with temperature. The results suggest that temperature has significant effects on bidirectional transport and can be used to

Structural and Conformational Chemistry from Electrochemical Molecular Machines. Replicating Biological Functions. A Review.

Science.gov (United States)

Otero, Toribio F

2017-12-14

Each constitutive chain of a conducting polymer electrode acts as a reversible multi-step electrochemical molecular motor: reversible reactions drive reversible conformational movements of the chain. The reaction-driven cooperative actuation of those molecular machines generates, or destroys, inside the film the free volume required to lodge/expel balancing counterions and solvent: reactions drive reversible film volume variations, which basic structural components are here identified and quantified from electrochemical responses. The content of the reactive dense gel (chemical molecular machines, ions and water) mimics that of the intracellular matrix in living functional cells. Reaction-driven properties (composition-dependent properties) and devices replicate biological functions and organs. An emerging technological world of soft, wet, reaction-driven, multifunctional and biomimetic devices and the concomitant zoomorphic or anthropomorphic robots is presented. © 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ins and outs of systems biology vis-à-vis molecular biology: continuation or clear cut?

Science.gov (United States)

De Backer, Philippe; De Waele, Danny; Van Speybroeck, Linda

2010-03-01

The comprehension of living organisms in all their complexity poses a major challenge to the biological sciences. Recently, systems biology has been proposed as a new candidate in the development of such a comprehension. The main objective of this paper is to address what systems biology is and how it is practised. To this end, the basic tools of a systems biological approach are explored and illustrated. In addition, it is questioned whether systems biology 'revolutionizes' molecular biology and 'transcends' its assumed reductionism. The strength of this claim appears to depend on how molecular and systems biology are characterised and on how reductionism is interpreted. Doing credit to molecular biology and to methodological reductionism, it is argued that the distinction between molecular and systems biology is gradual rather than sharp. As such, the classical challenge in biology to manage, interpret and integrate biological data into functional wholes is further intensified by systems biology's use of modelling and bioinformatics, and by its scale enlargement.

Highly sensitive detection of NT-proBNP by molecular motor

Directory of Open Access Journals (Sweden)

Jie Zhang

2017-03-01

Full Text Available FoF1-ATPase is an active rotary motor, and generates three-ATP for each rotation. At saturated substrate concentration, the motor can achieve about 103 r.p.m, which means one motor can generate about 105 ATP molecules during 30 min. Here, we constituted a novel nanodevice with a molecular rotary motor and a “battery”, FoF1-ATPase and chromatophore, and presented a novel method of sandwich type rotary biosensor based on ε subunit with one target-to-one motor, in which one target corresponds 105 ATP molecules as detection signals during 30 min. The target such as NT-proBNP detection demonstrated that this novel nanodevice has potential to be developed into an ultrasensitive biosensor to detect low expressed targets.

Measurement Frontiers in Molecular Biology

Science.gov (United States)

Laderman, Stephen

2009-03-01

Developments of molecular measurements and manipulations have long enabled forefront research in evolution, genetics, biological development and its dysfunction, and the impact of external factors on the behavior of cells. Measurement remains at the heart of exciting and challenging basic and applied problems in molecular and cell biology. Methods to precisely determine the identity and abundance of particular molecules amongst a complex mixture of similar and dissimilar types require the successful design and integration of multiple steps involving biochemical manipulations, separations, physical probing, and data processing. Accordingly, today's most powerful methods for characterizing life at the molecular level depend on coordinated advances in applied physics, biochemistry, chemistry, computer science, and engineering. This is well illustrated by recent approaches to the measurement of DNA, RNA, proteins, and intact cells. Such successes underlie well founded visions of how molecular biology can further assist in answering compelling scientific questions and in enabling the development of remarkable advances in human health. These visions, in turn, are motivating the interdisciplinary creation of even more comprehensive measurements. As a further and closely related consequence, they are motivating innovations in the conceptual and practical approaches to organizing and visualizing large, complex sets of interrelated experimental results and distilling from those data compelling, informative conclusions.

Understanding molecular motor walking along a microtubule: a themosensitive asymmetric Brownian motor driven by bubble formation.

Science.gov (United States)

Arai, Noriyoshi; Yasuoka, Kenji; Koishi, Takahiro; Ebisuzaki, Toshikazu; Zeng, Xiao Cheng

2013-06-12

The "asymmetric Brownian ratchet model", a variation of Feynman's ratchet and pawl system, is invoked to understand the kinesin walking behavior along a microtubule. The model system, consisting of a motor and a rail, can exhibit two distinct binding states, namely, the random Brownian state and the asymmetric potential state. When the system is transformed back and forth between the two states, the motor can be driven to "walk" in one direction. Previously, we suggested a fundamental mechanism, that is, bubble formation in a nanosized channel surrounded by hydrophobic atoms, to explain the transition between the two states. In this study, we propose a more realistic and viable switching method in our computer simulation of molecular motor walking. Specifically, we propose a thermosensitive polymer model with which the transition between the two states can be controlled by temperature pulses. Based on this new motor system, the stepping size and stepping time of the motor can be recorded. Remarkably, the "walking" behavior observed in the newly proposed model resembles that of the realistic motor protein. The bubble formation based motor not only can be highly efficient but also offers new insights into the physical mechanism of realistic biomolecule motors.

The Molecular Era of Surfactant Biology

OpenAIRE

Whitsett, Jeffrey A.

2014-01-01

Advances in the physiology, biochemistry, molecular and cell biology of the pulmonary surfactant system transformed the clinical care and outcome of preterm infants with respiratory distress syndrome. The molecular era of surfactant biology provided genetic insights into the pathogenesis of pulmonary disorders, previously termed “idiopathic” that affect newborn infants, children and adults. Knowledge related to the structure and function of the surfactant proteins and their roles in alveolar ...

Teaching Molecular Biology with Microcomputers.

Science.gov (United States)

Reiss, Rebecca; Jameson, David

1984-01-01

Describes a series of computer programs that use simulation and gaming techniques to present the basic principles of the central dogma of molecular genetics, mutation, and the genetic code. A history of discoveries in molecular biology is presented and the evolution of these computer assisted instructional programs is described. (MBR)

The progress of molecular biology in radiation research

International Nuclear Information System (INIS)

Wei Kang

1989-01-01

The recent progress in application of molecular biology techniques in the study of radiation biology is reviewed. The three sections are as follows: (1) the study of DNA damage on molecular level, (2) the molecular mechanism of radiation cell genetics, including chromosome abberation and cell mutation, (3) the study on DNA repair gene with DNA mediated gene transfer techniques

Asymmetric Synthesis of Second-Generation Light-Driven Molecular Motors

NARCIS (Netherlands)

van Leeuwen, Thomas; Danowski, Wojciech; Otten, Edwin; Wezenberg, Sander J; Feringa, Ben L

2017-01-01

The enantiomeric homogeneity of light-driven molecular motors based on overcrowded alkenes is crucial in their application as either unidirectional rotors or as chiral multistate switches. It was challenging to obtain these compounds as single enantiomers via the established synthetic procedures due

Advanced molecular devices based on light-driven molecular motors

NARCIS (Netherlands)

Chen, Jiawen

2015-01-01

Nature has provided a large collection of molecular machines and devices that are among the most amazing nanostructures on this planet. These machines are able to operate complex biological processes which are of great importance in our organisms. Inspired by these natural devices, artificial

The molecular biology in wound healing & non-healing wound.

Science.gov (United States)

Qing, Chun

2017-08-01

The development of molecular biology and other new biotechnologies helps us to recognize the wound healing and non-healing wound of skin in the past 30 years. This review mainly focuses on the molecular biology of many cytokines (including growth factors) and other molecular factors such as extracellular matrix (ECM) on wound healing. The molecular biology in cell movement such as epidermal cells in wound healing was also discussed. Moreover many common chronic wounds such as pressure ulcers, leg ulcers, diabetic foot wounds, venous stasis ulcers, etc. usually deteriorate into non-healing wounds. Therefore the molecular biology such as advanced glycation end products (AGEs) and other molecular factors in diabetes non-healing wounds were also reviewed. Copyright © 2017 Daping Hospital and the Research Institute of Surgery of the Third Military Medical University. Production and hosting by Elsevier B.V. All rights reserved.

The molecular biology of WHO grade I astrocytomas.

Science.gov (United States)

Marko, Nicholas F; Weil, Robert J

2012-12-01

World Health Organization (WHO) grade I astrocytomas include pilocytic astrocytoma (PA) and subependymal giant cell astrocytoma (SEGA). As technologies in pharmacologic neo-adjuvant therapy continue to progress and as molecular characteristics are progressively recognized as potential markers of both clinically significant tumor subtypes and response to therapy, interest in the biology of these tumors has surged. An updated review of the current knowledge of the molecular biology of these tumors is needed. We conducted a Medline search to identify published literature discussing the molecular biology of grade I astrocytomas. We then summarized this literature and discuss it in a logical framework through which the complex biology of these tumors can be clearly understood. A comprehensive review of the molecular biology of WHO grade I astrocytomas is presented. The past several years have seen rapid progress in the level of understanding of PA in particular, but the molecular literature regarding both PA and SEGA remains nebulous, ambiguous, and occasionally contradictory. In this review we provide a comprehensive discussion of the current understanding of the chromosomal, genomic, and epigenomic features of both PA and SEGA and provide a logical framework in which these data can be more readily understood.

Associations of biological factors and affordances in the home with infant motor development.

Science.gov (United States)

Saccani, Raquel; Valentini, Nadia C; Pereira, Keila Rg; Müller, Alessandra B; Gabbard, Carl

2013-04-01

Whereas considerable work has been published regarding biological factors associated with infant health, much less is known about the associations of environmental context with infant development - the focus of the present cross-sectional study. Data were collected on 561 infants, aged newborn to 18 months. Measures included the Affordances in the Home Environment for Motor Development-Infant Scale, Alberta Infant Motor Scale, and selected bio/medical factors. Correlation and regression were used to analyze the data. Home environmental factors were associated with children's motor development as much as some typically high-risk biologic factors. The home environment partially explained infant development outcomes and infants at risk could possibly be helped with a home assessment for affordances. © 2012 The Authors. Pediatrics International © 2012 Japan Pediatric Society.

From Molecular Biology to Biomedicine

International Nuclear Information System (INIS)

Salas, M.

2009-01-01

From Molecular Biology to Biomedicine. The well known molecular biologist Margarita Salas offered an informative conference at the CSN on progress in these areas since the discovery, more than half a century ago, of the structure of the molecule carrying genetic information, DNA, work that is having an enormous impact in areas such as biomedicine and foodstuff production. (Author)

Isotopes in molecular biology

International Nuclear Information System (INIS)

Goldfarb, P.S.G.

1988-01-01

The use of radioisotopes in molecular biology, with particular reference to the structure and functions of DNA, RNA and the cellular synthesis of proteins, is discussed. The use of labelled DNA and RNA in diagnostic techniques is presented. (U.K.)

Human spinal motor control

DEFF Research Database (Denmark)

Nielsen, Jens Bo

2016-01-01

Human studies in the past three decades have provided us with an emerging understanding of how cortical and spinal networks collaborate to ensure the vast repertoire of human behaviors. We differ from other animals in having direct cortical connections to spinal motoneurons, which bypass spinal...... the central motor command by opening or closing sensory feedback pathways. In the future, human studies of spinal motor control, in close collaboration with animal studies on the molecular biology of the spinal cord, will continue to document the neural basis for human behavior. Expected final online...

Interactive analysis of systems biology molecular expression data

Directory of Open Access Journals (Sweden)

Prabhakar Sunil

2008-02-01

Full Text Available Abstract Background Systems biology aims to understand biological systems on a comprehensive scale, such that the components that make up the whole are connected to one another and work through dependent interactions. Molecular correlations and comparative studies of molecular expression are crucial to establishing interdependent connections in systems biology. The existing software packages provide limited data mining capability. The user must first generate visualization data with a preferred data mining algorithm and then upload the resulting data into the visualization package for graphic visualization of molecular relations. Results Presented is a novel interactive visual data mining application, SysNet that provides an interactive environment for the analysis of high data volume molecular expression information of most any type from biological systems. It integrates interactive graphic visualization and statistical data mining into a single package. SysNet interactively presents intermolecular correlation information with circular and heatmap layouts. It is also applicable to comparative analysis of molecular expression data, such as time course data. Conclusion The SysNet program has been utilized to analyze elemental profile changes in response to an increasing concentration of iron (Fe in growth media (an ionomics dataset. This study case demonstrates that the SysNet software is an effective platform for interactive analysis of molecular expression information in systems biology.

Assessment of Knowledge of Participants on Basic Molecular Biology Techniques after 5-Day Intensive Molecular Biology Training Workshops in Nigeria

Science.gov (United States)

Yisau, J. I.; Adagbada, A. O.; Bamidele, T.; Fowora, M.; Brai, B. I. C.; Adebesin, O.; Bamidele, M.; Fesobi, T.; Nwaokorie, F. O.; Ajayi, A.; Smith, S. I.

2017-01-01

The deployment of molecular biology techniques for diagnosis and research in Nigeria is faced with a number of challenges, including the cost of equipment and reagents coupled with the dearth of personnel skilled in the procedures and handling of equipment. Short molecular biology training workshops were conducted at the Nigerian Institute of…

Ordinary differential equations with applications in molecular biology.

Science.gov (United States)

Ilea, M; Turnea, M; Rotariu, M

2012-01-01

Differential equations are of basic importance in molecular biology mathematics because many biological laws and relations appear mathematically in the form of a differential equation. In this article we presented some applications of mathematical models represented by ordinary differential equations in molecular biology. The vast majority of quantitative models in cell and molecular biology are formulated in terms of ordinary differential equations for the time evolution of concentrations of molecular species. Assuming that the diffusion in the cell is high enough to make the spatial distribution of molecules homogenous, these equations describe systems with many participating molecules of each kind. We propose an original mathematical model with small parameter for biological phospholipid pathway. All the equations system includes small parameter epsilon. The smallness of epsilon is relative to the size of the solution domain. If we reduce the size of the solution region the same small epsilon will result in a different condition number. It is clear that the solution for a smaller region is less difficult. We introduce the mathematical technique known as boundary function method for singular perturbation system. In this system, the small parameter is an asymptotic variable, different from the independent variable. In general, the solutions of such equations exhibit multiscale phenomena. Singularly perturbed problems form a special class of problems containing a small parameter which may tend to zero. Many molecular biology processes can be quantitatively characterized by ordinary differential equations. Mathematical cell biology is a very active and fast growing interdisciplinary area in which mathematical concepts, techniques, and models are applied to a variety of problems in developmental medicine and bioengineering. Among the different modeling approaches, ordinary differential equations (ODE) are particularly important and have led to significant advances

Agent-Based Modeling in Molecular Systems Biology.

Science.gov (United States)

Soheilypour, Mohammad; Mofrad, Mohammad R K

2018-06-08

Molecular systems orchestrating the biology of the cell typically involve a complex web of interactions among various components and span a vast range of spatial and temporal scales. Computational methods have advanced our understanding of the behavior of molecular systems by enabling us to test assumptions and hypotheses, explore the effect of different parameters on the outcome, and eventually guide experiments. While several different mathematical and computational methods are developed to study molecular systems at different spatiotemporal scales, there is still a need for methods that bridge the gap between spatially-detailed and computationally-efficient approaches. In this review, we summarize the capabilities of agent-based modeling (ABM) as an emerging molecular systems biology technique that provides researchers with a new tool in exploring the dynamics of molecular systems/pathways in health and disease. © 2018 WILEY Periodicals, Inc.

2010 CELL AND MOLECULAR FUNGAL BIOLOGY GORDON RESEARCH CONFERENCE, JUNE 13-18, 2010

Energy Technology Data Exchange (ETDEWEB)

Michelle Momany

2010-06-18

The Cellular and Molecular Fungal Biology Conference provides a forum for presentation of the latest advances in fungal research with an emphasis on filamentous fungi. This open-registration scientific meeting brings together the leading scientists from academia, government and industry to discuss current research results and future directions at Holderness School, an outstanding venue for scientific interaction. A key objective of the conference is to foster interaction among scientists working on model fungi such as Saccharomyces cerevisiae, Schizosaccharomyces pombe, Neurospora crassa and Aspergillus nidulans and scientists working on a variety of filamentous fungi whose laboratory tractability is often inversely proportional to their medical, industrial or ecological importance. Sessions will be devoted to Systems Biology, Fungi and Cellulosic Biomass, Small RNAs, Population Genomics, Symbioses, Pathogenesis, Membrane Trafficking and Polarity, and Cytoskeleton and Motors. A session will also be devoted to hot topics picked from abstracts. The CMFB conference provides a unique opportunity to examine the breadth of fungal biology in a small meeting format that encourages in-depth discussion among the attendees.

Motor properties from persistence: a linear molecular walker lacking spatial and temporal asymmetry

International Nuclear Information System (INIS)

Zuckermann, Martin J; Forde, Nancy R; Angstmann, Christopher N; Schmitt, Regina; Linke, Heiner; Blab, Gerhard A; Bromley, Elizabeth HC; Curmi, Paul MG

2015-01-01

The stepping direction of linear molecular motors is usually defined by a spatial asymmetry of the motor, its track, or both. Here we present a model for a molecular walker that undergoes biased directional motion along a symmetric track in the presence of a temporally symmetric chemical cycle. Instead of using asymmetry, directionality is achieved by persistence. At small load force the walker can take on average thousands of steps in a given direction until it stochastically reverses direction. We discuss a specific experimental implementation of a synthetic motor based on this design and find, using Langevin and Monte Carlo simulations, that a realistic walker can work against load forces on the order of picoNewtons with an efficiency of ∼18%, comparable to that of kinesin. In principle, the walker can be turned into a permanent motor by externally monitoring the walker’s momentary direction of motion, and using feedback to adjust the direction of a load force. We calculate the thermodynamic cost of using feedback to enhance motor performance in terms of the Shannon entropy, and find that it reduces the efficiency of a realistic motor only marginally. We discuss the implications for natural protein motor performance in the context of the strong performance of this design based only on a thermal ratchet. (paper)

The stochastic chemomechanics of the F(1)-ATPase molecular motor.

Science.gov (United States)

Gaspard, P; Gerritsma, E

2007-08-21

We report a theoretical study of the F(1)-ATPase molecular rotary motor experimentally studied by R. Yasuda, H. Noji, M. Yoshida, K. Kinosita Jr., H. Itoh [Nature 410 (2001) 898]. The motor is modeled as a stochastic process for the angle of its shaft and the chemical state of its catalytic sites. The stochastic process is ruled by six coupled Fokker-Planck equations for the biased diffusion of the angle and the random jumps between the chemical states. The model reproduces the experimental observations that the motor proceeds by substeps and the rotation rate saturates at high concentrations of adenosine triphosphate or at low values of the friction coefficient. Moreover, predictions are made about the dependence of the rotation rate on temperature, and about the behavior of the F(1) motor under the effect of an external torque, especially, in the regime of synthesis of adenosine triphosphate.

Design principles and optimal performance for molecular motors under realistic constraints

Science.gov (United States)

Tu, Yuhai; Cao, Yuansheng

2018-02-01

The performance of a molecular motor, characterized by its power output and energy efficiency, is investigated in the motor design space spanned by the stepping rate function and the motor-track interaction potential. Analytic results and simulations show that a gating mechanism that restricts forward stepping in a narrow window in configuration space is needed for generating high power at physiologically relevant loads. By deriving general thermodynamics laws for nonequilibrium motors, we find that the maximum torque (force) at stall is less than its theoretical limit for any realistic motor-track interactions due to speed fluctuations. Our study reveals a tradeoff for the motor-track interaction: while a strong interaction generates a high power output for forward steps, it also leads to a higher probability of wasteful spontaneous back steps. Our analysis and simulations show that this tradeoff sets a fundamental limit to the maximum motor efficiency in the presence of spontaneous back steps, i.e., loose-coupling. Balancing this tradeoff leads to an optimal design of the motor-track interaction for achieving a maximum efficiency close to 1 for realistic motors that are not perfectly coupled with the energy source. Comparison with existing data and suggestions for future experiments are discussed.

Ultrafast Dynamics in Light-Driven Molecular Rotary Motors Probed by Femtosecond Stimulated Raman Spectroscopy

NARCIS (Netherlands)

Hall, Christopher R.; Conyard, Jamie; Heisler, Ismael A.; Jones, Garth; Frost, James; Browne, Wesley R.; Feringa, Ben L.; Meech, Stephen R.

2017-01-01

Photochemical isomerization in sterically crowded chiral alkenes is the driving force for molecular rotary motors in nanoscale machines. Here the excited-state dynamics and structural evolution of the prototypical light-driven rotary motor are followed on the ultrafast time scale by femtosecond

Evolution of egg coats: linking molecular biology and ecology.

Science.gov (United States)

Shu, Longfei; Suter, Marc J-F; Räsänen, Katja

2015-08-01

One central goal of evolutionary biology is to explain how biological diversity emerges and is maintained in nature. Given the complexity of the phenotype and the multifaceted nature of inheritance, modern evolutionary ecological studies rely heavily on the use of molecular tools. Here, we show how molecular tools help to gain insight into the role of egg coats (i.e. the extracellular structures surrounding eggs and embryos) in evolutionary diversification. Egg coats are maternally derived structures that have many biological functions from mediating fertilization to protecting the embryo from environmental hazards. They show great molecular, structural and functional diversity across species, but intraspecific variability and the role of ecology in egg coat evolution have largely been overlooked. Given that much of the variation that influences egg coat function is ultimately determined by their molecular phenotype, cutting-edge molecular tools (e.g. proteomics, glycomics and transcriptomics), combined with functional assays, are needed for rigorous inferences on their evolutionary ecology. Here, we identify key research areas and highlight emerging molecular techniques that can increase our understanding of the role of egg coats in the evolution of biological diversity, from adaptation to speciation. © 2015 John Wiley & Sons Ltd.

A National Comparison of Biochemistry and Molecular Biology Capstone Experiences

Science.gov (United States)

Aguanno, Ann; Mertz, Pamela; Martin, Debra; Bell, Ellis

2015-01-01

Recognizing the increasingly integrative nature of the molecular life sciences, the "American Society for Biochemistry and Molecular Biology" (ASBMB) recommends that Biochemistry and Molecular Biology (BMB) programs develop curricula based on concepts, content, topics, and expected student outcomes, rather than courses. To that end,…

How to make spinal motor neurons.

Science.gov (United States)

Davis-Dusenbery, Brandi N; Williams, Luis A; Klim, Joseph R; Eggan, Kevin

2014-02-01

All muscle movements, including breathing, walking, and fine motor skills rely on the function of the spinal motor neuron to transmit signals from the brain to individual muscle groups. Loss of spinal motor neuron function underlies several neurological disorders for which treatment has been hampered by the inability to obtain sufficient quantities of primary motor neurons to perform mechanistic studies or drug screens. Progress towards overcoming this challenge has been achieved through the synthesis of developmental biology paradigms and advances in stem cell and reprogramming technology, which allow the production of motor neurons in vitro. In this Primer, we discuss how the logic of spinal motor neuron development has been applied to allow generation of motor neurons either from pluripotent stem cells by directed differentiation and transcriptional programming, or from somatic cells by direct lineage conversion. Finally, we discuss methods to evaluate the molecular and functional properties of motor neurons generated through each of these techniques.

Teaching molecular genetics: Chapter 1--Background principles and methods of molecular biology.

NARCIS (Netherlands)

Knoers, N.V.A.M.; Monnens, L.A.H.

2006-01-01

In this first chapter of the series "Teaching molecular genetics," an introduction to molecular genetics is presented. We describe the structure of DNA and genes and explain in detail the central dogma of molecular biology, that is, the flow of genetic information from DNA via RNA to polypeptide

Chemoradiotherapy and molecular biology

International Nuclear Information System (INIS)

Hasegawa, Masatoshi; Mitsuhashi, Norio; Niibe, Hideo

2000-01-01

The current status of chemoradiotherapy was reviewed from the standpoint of molecular biology. Chemoradiotherapy was conducted to achieve systemic tumor control, to intensify the response to irradiation, and to reduce adverse reactions. The mechanisms of the efficacy of chemoradiotherapy were: modification of dose-response relationships, inhibition of tumor cell recovery from sublethal damage or potential lethal damage, effects on cell dynamics and the cell cycle, improvement of blood flow or reoxygenation, recruitment, improvement of drug uptake, increased cell damage. Cell death (necrosis and apoptosis) and cancer-related genes were described, as the essential points, because they are involved in the response to chemoradiotherapy. Cisplatin (platinum compound), 5-fluorouracil, etoposide, and taxoid (paclitaxel, docetaxel) were the principal anticancer agents used for chemoradiotherapy, and they enhanced the effects of irradiation. However, even when good responses or synergism between anticancer drug and radiotherapy was observed in in vitro studies, there was little therapeutic advantage clinically. Data from in vitro and in vivo studies should be collected and systemized, and ''molecular biology in chemotherapy'' that can be applied clinically may become established. (K.H.)

Molecular motor assembly of a biomimetic system

Institute of Scientific and Technical Information of China (English)

无

2008-01-01

@@ Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction.

Systems biology for molecular life sciences and its impact in biomedicine.

Science.gov (United States)

Medina, Miguel Ángel

2013-03-01

Modern systems biology is already contributing to a radical transformation of molecular life sciences and biomedicine, and it is expected to have a real impact in the clinical setting in the next years. In this review, the emergence of systems biology is contextualized with a historic overview, and its present state is depicted. The present and expected future contribution of systems biology to the development of molecular medicine is underscored. Concerning the present situation, this review includes a reflection on the "inflation" of biological data and the urgent need for tools and procedures to make hidden information emerge. Descriptions of the impact of networks and models and the available resources and tools for applying them in systems biology approaches to molecular medicine are provided as well. The actual current impact of systems biology in molecular medicine is illustrated, reviewing two cases, namely, those of systems pharmacology and cancer systems biology. Finally, some of the expected contributions of systems biology to the immediate future of molecular medicine are commented.

Laboratory of Cell and Molecular Biology

Data.gov (United States)

Federal Laboratory Consortium — The Laboratory of Cell and Molecular Biology investigates the organization, compartmentalization, and biochemistry of eukaryotic cells and the pathology associated...

Nanoconfined catalytic Ångström-size motors

Energy Technology Data Exchange (ETDEWEB)

Colberg, Peter H., E-mail: pcolberg@chem.utoronto.ca; Kapral, Raymond, E-mail: rkapral@chem.utoronto.ca [Chemical Physics Theory Group, Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6 (Canada)

2015-11-14

Self-propelled chemically powered synthetic micron and nano-scale motors are being intensively studied because of the wide range of potential applications that exploit their directed motion. This paper considers even smaller Ångström-size synthetic motors. Such very small motors in bulk solution display effects arising from their self-propulsion. Recent experiments have shown that small-molecule catalysts and single enzyme molecules exhibit properties that have been attributed to their chemical activity. Molecular dynamics is used to investigate the properties of very small Ångström-size synthetic chemically powered sphere-dimer motors in a simple atomic-like solvent confined between walls separated by distances of tens of nanometers. Evidence for strong structural ordering of the motors between the walls, which reflects the finite size of solvent molecules and depends on solvent depletion forces, is provided. Dynamical properties, such as average motor velocity, orientational relaxation, and mean square displacement, are anisotropic and depend on the distance from the walls. This research provides information needed for potential applications that use molecular-scale motors in the complex confined geometries encountered in biology and the laboratory.

Nanoconfined catalytic Ångström-size motors

International Nuclear Information System (INIS)

Colberg, Peter H.; Kapral, Raymond

2015-01-01

Self-propelled chemically powered synthetic micron and nano-scale motors are being intensively studied because of the wide range of potential applications that exploit their directed motion. This paper considers even smaller Ångström-size synthetic motors. Such very small motors in bulk solution display effects arising from their self-propulsion. Recent experiments have shown that small-molecule catalysts and single enzyme molecules exhibit properties that have been attributed to their chemical activity. Molecular dynamics is used to investigate the properties of very small Ångström-size synthetic chemically powered sphere-dimer motors in a simple atomic-like solvent confined between walls separated by distances of tens of nanometers. Evidence for strong structural ordering of the motors between the walls, which reflects the finite size of solvent molecules and depends on solvent depletion forces, is provided. Dynamical properties, such as average motor velocity, orientational relaxation, and mean square displacement, are anisotropic and depend on the distance from the walls. This research provides information needed for potential applications that use molecular-scale motors in the complex confined geometries encountered in biology and the laboratory

[Molecular Biology on the Mechanisms of Autism Spectrum Disorder for Clinical Psychiatrists].

Science.gov (United States)

Makinodan, Manabu

2015-01-01

While, in general, a certain number of clinical psychiatrists might not be familiar with molecular biology, the mechanisms of mental illnesses have been uncovered by molecular biology for decades. Among mental illnesses, even biological psychiatrists and neuroscientists have paid less attention to the biological treatment of autism spectrum disorder (ASD) than Alzheimer's disease and schizophrenia since ASD has been regarded as a developmental disorder that was seemingly untreatable. However, multifaceted methods of molecular biology have revealed the mechanisms that would lead to the medication of ASD. In this article, how molecular biology dissects the pathobiology of ASD is described in order to announce the possibilities of biological treatment for clinical psychiatrists.

Third international congress of plant molecular biology: Molecular biology of plant growth and development

Energy Technology Data Exchange (ETDEWEB)

Hallick, R.B. [ed.

1995-02-01

The Congress was held October 6-11, 1991 in Tucson with approximately 3000 scientists attending and over 300 oral presentations and 1800 posters. Plant molecular biology is one of the most rapidly developing areas of the biological sciences. Recent advances in the ability to isolate genes, to study their expression, and to create transgenic plants have had a major impact on our understanding of the many fundamental plant processes. In addition, new approaches have been created to improve plants for agricultural purposes. This is a book of presentation and posters from the conference.

A Diagnostic Assessment for Introductory Molecular and Cell Biology

Science.gov (United States)

Shi, Jia; Wood, William B.; Martin, Jennifer M.; Guild, Nancy A.; Vicens, Quentin; Knight, Jennifer K.

2010-01-01

We have developed and validated a tool for assessing understanding of a selection of fundamental concepts and basic knowledge in undergraduate introductory molecular and cell biology, focusing on areas in which students often have misconceptions. This multiple-choice Introductory Molecular and Cell Biology Assessment (IMCA) instrument is designed…

Synthetic biology: engineering molecular computers

CERN Multimedia

CERN. Geneva

2018-01-01

Complicated systems cannot survive the rigors of a chaotic environment, without balancing mechanisms that sense, decide upon and counteract the exerted disturbances. Especially so with living organisms, forced by competition to incredible complexities, escalating also their self-controlling plight. Therefore, they compute. Can we harness biological mechanisms to create artificial computing systems? Biology offers several levels of design abstraction: molecular machines, cells, organisms... ranging from the more easily-defined to the more inherently complex. At the bottom of this stack we find the nucleic acids, RNA and DNA, with their digital structure and relatively precise interactions. They are central enablers of designing artificial biological systems, in the confluence of engineering and biology, that we call Synthetic biology. In the first part, let us follow their trail towards an overview of building computing machines with molecules -- and in the second part, take the case study of iGEM Greece 201...

Molecular infection biology : interactions between microorganisms and cells

National Research Council Canada - National Science Library

Hacker, Jörg (Jörg Hinrich); Heesemann, Jurgen

2002-01-01

... and epidemiology of infectious diseases. Investigators, specialists, clinicians, and graduate students in biology, pharmacy, and medicine will find Molecular Infection Biology an invaluable addition to their professional libraries...

Commentary: Biochemistry and Molecular Biology Educators Launch National Network

Science.gov (United States)

Bailey, Cheryl; Bell, Ellis; Johnson, Margaret; Mattos, Carla; Sears, Duane; White, Harold B.

2010-01-01

The American Society of Biochemistry and Molecular Biology (ASBMB) has launched an National Science Foundation (NSF)-funded 5 year project to support biochemistry and molecular biology educators learning what and how students learn. As a part of this initiative, hundreds of life scientists will plan and develop a rich central resource for…

Enantiopure Functional Molecular Motors Obtained by a Switchable Chiral-Resolution Process

NARCIS (Netherlands)

van Leeuwen, Thomas; Gan, Jefri; Kistemaker, Jos C. M.; Pizzolato, Stefano F.; Chang, Mu-Chieh; Feringa, Ben L.

2016-01-01

Molecular switches, rotors, and motors play an important role in the development of nano-machines and devices, as well as responsive and adaptive functional materials. For unidirectional rotors based on chiral overcrowded alkenes, their stereochemical homogeneity is of crucial importance. Herein, a

Molecular biology applications to infectious diseases diagnostic

International Nuclear Information System (INIS)

2001-01-01

This project goes directed to the applications of the techniques of molecular biology in hepatitis virus.A great advance of these techniques it allows its application to the diagnose molecular and it becomes indispensable to have these fundamental tools in the field of the Health Public for the detection precocious, pursuit of the treatment, the one predicts and the evolution of the patient hepatitis bearing virus technical.Use of molecular biology to increase the handling and the control of the patients with hepatitis B and C and to detect an adult numbers of positive cases by means of the training and integration of all the countries participating.Implement the technique of PCR to identify the virus of the hepatitis B and C,implement quantification methods and genotipification for these virus

Molecular biology of Plasmodiophora brassicae

DEFF Research Database (Denmark)

Siemens, Johannes; Bulman, Simon; Rehn, Frank

2009-01-01

of several genes have been revealed, and the expression of those genes has been linked to development of clubroot to some extent. In addition, the sequence data have reinforced the inclusion of the plasmodiophorids within the Cercozoa. The recent successes in molecular biology have produced new approaches...

Molecular Theory of the Living Cell Concepts, Molecular Mechanisms, and Biomedical Applications

CERN Document Server

Ji, Sungchul

2012-01-01

This book presents a comprehensive molecular theory of the living cell based on over thirty concepts, principles and laws imported from thermodynamics, statistical mechanics, quantum mechanics, chemical kinetics, informatics, computer science, linguistics, semiotics, and philosophy. The author formulates physically, chemically and enzymologically realistic molecular mechanisms to account for the basic living processes such as ligand-receptor interactions, protein folding, single-molecule enzymic catalysis, force-generating mechanisms in molecular motors, signal transduction, regulation of the genome-wide RNA metabolism, morphogenesis, the micro-macro coupling in coordination dynamics, the origin of life, and the mechanisms of biological evolution itself. Possible solutions to basic and practical problems facing contemporary biology and biomedical sciences have been suggested, including pharmacotheragnostics and personalized medicine.

NanoShuttles: Harnessing Motor Proteins to Transport Cargo in Synthetic Environments

Science.gov (United States)

Vogel, V.; Hess, H.

Motors have become a crucial commodity in our daily lives, from transportation to driving conveyor belts that enable the sequential assembly of cars and other industrial machines. For the sequential assembly of building blocks at the nanoscale that would not assemble spontaneously into larger functional systems, however, active transport systems are not yet available. In contrast, cells have evolved sophisticated molecular machinery that drives movement and active transport. Driven by the conversion of chemical into mechanical energy, namely through hydrolysis of the biological fuel ATP, molecular motors enable cells to operate far away from equilibrium by transporting organelles and molecules to designated locations within the cell, often against concentration gradients. Inspired by the biological concept of active transport, major efforts are underway to learn how to build nanoscale transport systems that are driven by molecular motors. Emerging engineering principles are discussed of how to build tracks and junctions to guide such nanoshuttles, how to load them with cargo and control their speed, how to use active transport to assemble mesoscopic structures that would otherwise not assemble spontaneously and what polymeric materials to choose to integrate motors into MEMS and other biohybrid devices. Finally, two applications that exploit the physical properties of microtubules are discussed, surface imaging by a swarm of microtubules and a self-assembled picoNewton force meter to probe receptor-ligand interactions.

Molecular biology of pancreatic cancer: how useful is it in clinical practice?

Science.gov (United States)

Sakorafas, George H; Smyrniotis, Vasileios

2012-07-10

During the recent two decades dramatic advances of molecular biology allowed an in-depth understanding of pancreatic carcinogenesis. It is currently accepted that pancreatic cancer has a genetic component. The real challenge is now how these impressive advances could be used in clinical practice. To critically present currently available data regarding clinical application of molecular biology in pancreatic cancer. Reports about clinical implications of molecular biology in patients with pancreatic cancer were retrieved from PubMed. These reports were selected on the basis of their clinical relevance, and the data of their publication (preferentially within the last 5 years). Emphasis was placed on reports investigating diagnostic, prognostic, and therapeutic implications. Molecular biology can be used to identify individuals at high-risk for pancreatic cancer development. Intensive surveillance is indicated in these patients to detect pancreatic neoplasia ideally at a preinvasive stage, when curative resection is still possible. Molecular biology can also be used in the diagnosis of pancreatic cancer, with molecular analysis on samples of biologic material, such as serum or plasma, duodenal fluid or preferentially pure pancreatic juice, pancreatic cells or tissue, and stools. Molecular indices have also prognostic significance. Finally, molecular biology may have therapeutic implications by using various therapeutic approaches, such as antiangiogenic factors, purine synthesis inhibitors, matrix metalloproteinase inhibitors, factors modulating tumor-stroma interaction, inactivation of the hedgehog pathway, gene therapy, oncolytic viral therapy, immunotherapy (both passive as well as active) etc. Molecular biology may have important clinical implications in patients with pancreatic cancer and represents one of the most active areas on cancer research. Hopefully clinical applications of molecular biology in pancreatic cancer will expand in the future, improving the

Molecular biology - Part I: Techniques, terminology, and concepts

International Nuclear Information System (INIS)

Brown, J. Martin

1996-01-01

Purpose/Objective: One of the barriers to understanding modern molecular biology is the lack of a clear understanding of the relevant terminology, techniques, and concepts. This refresher course is intended to address these deficiencies starting from a basic level. The lecture will cover many of the common uses of recombinant DNA, including gene cloning and manipulation. The goal is to enable the nonspecialist to increase his or her understanding of molecular biology in order to more fully enjoy reading current publications and/or listening seminars. Radiation biologists trying to understand a little more molecular biology should also benefit. The following concepts will be among those explained and illustrated: restriction endonucleases, gel electrophoresis, gene cloning, use of vectors such as plasmids, bacteriophage, cosmids and viruses, cDNA and genomic libraries, Southern, Northern, and Western blotting, fluorescent in situ hybridization, polymerase chain reaction (PCR), gel retardation, and reporter gene assays

Biología molecular y cáncer de tiroides Molecular biology and thyroid cancer

Directory of Open Access Journals (Sweden)

Juan Cassola Santana

2010-12-01

Full Text Available Se realiza una revisión actualizada sobre aspectos de biología molecular que servirán de base al cirujano actuante para un mejor conocimiento del cáncer tiroideo. El objetivo radica en alertar a los cirujanos sobre las nuevas evaluaciones a las que podrán someterse los tumores de la tiroides, que implicarán cambios en toda la gama de conductas actuales en estos casos. Se señalan aspectos que sin duda cambiarán los conceptos que se manejan hoy día.A updating review is carry out on the features of molecular biology as a basis for acting surgeon to a better knowledge of thyroid cancer. The objective is to alert surgeons on the new assessments for this type of cancer, implicating changes in all the range of current behaviors in these cases. The features that will change the nowadays concepts in this respect.

Theoretical Molecular Biophysics

CERN Document Server

Scherer, Philipp

2010-01-01

"Theoretical Molecular Biophysics" is an advanced study book for students, shortly before or after completing undergraduate studies, in physics, chemistry or biology. It provides the tools for an understanding of elementary processes in biology, such as photosynthesis on a molecular level. A basic knowledge in mechanics, electrostatics, quantum theory and statistical physics is desirable. The reader will be exposed to basic concepts in modern biophysics such as entropic forces, phase separation, potentials of mean force, proton and electron transfer, heterogeneous reactions coherent and incoherent energy transfer as well as molecular motors. Basic concepts such as phase transitions of biopolymers, electrostatics, protonation equilibria, ion transport, radiationless transitions as well as energy- and electron transfer are discussed within the frame of simple models.

2012 Gordon Research Conference, Plant molecular biology, July 15-20 2012

Energy Technology Data Exchange (ETDEWEB)

Sussman, Michael R. [Univ. of Wisconsin, Madison, WI (United States)

2013-07-20

The 2012 Gordon Conference on Plant Molecular Biology will present cutting-edge research on molecular aspects of plant growth and development, with particular emphasis on recent discoveries in molecular mechanisms involved with plant signaling systems. The Conference will feature a wide range of topics in plant molecular biology including hormone receptors and early events in hormone signaling, plant perception of and response to plant pathogen and symbionts, as well as technological and biological aspects of epigenomics particularly as it relates to signaling systems that regulate plant growth and development. Genomic approaches to plant signaling will be emphasized, including genomic profiling technologies for quantifying various biological subsystems, such as the epigenome, transcriptome, phosphorylome, and metabolome. The meeting will include an important session devoted to answering the question, "What are the biological and technological limits of plant breeding/genetics, and how can they be solved"?

Teaching molecular genetics: Chapter 1--Background principles and methods of molecular biology.

Science.gov (United States)

Knoers, Nine V A M; Monnens, Leo A H

2006-02-01

In this first chapter of the series "Teaching molecular genetics," an introduction to molecular genetics is presented. We describe the structure of DNA and genes and explain in detail the central dogma of molecular biology, that is, the flow of genetic information from DNA via RNA to polypeptide (protein). In addition, several basic and frequently used general molecular tools, such as restriction enzymes, Southern blotting, DNA amplification and sequencing are discussed, in order to lay the foundations for the forthcoming chapters.

Brownian diode: Molecular motor based on a semi-permeable Brownian particle with internal potential drop

International Nuclear Information System (INIS)

Plyukhin, A.V.

2013-01-01

A model of an autonomous isothermal Brownian motor with an internal propulsion mechanism is considered. The motor is a Brownian particle which is semi-transparent for molecules of surrounding ideal gas. Molecular passage through the particle is controlled by a potential similar to that in the transition rate theory, i.e. characterized by two stationary states with a finite energy difference separated by a potential barrier. The internal potential drop maintains the diode-like asymmetry of molecular fluxes through the particle, which results in the particle's stationary drift.

Molecular motors that digest their track to rectify Brownian motion: processive movement of exonuclease enzymes.

Science.gov (United States)

Xie, Ping

2009-09-16

A general model is presented for the processive movement of molecular motors such as λ-exonuclease, RecJ and exonuclease I that use digestion of a DNA track to rectify Brownian motion along this track. Using this model, the translocation dynamics of these molecular motors is studied. The sequence-dependent pausing of λ-exonuclease, which results from a site-specific high affinity DNA interaction, is also studied. The theoretical results are consistent with available experimental data. Moreover, the model is used to predict the lifetime distribution and force dependence of these paused states.

Molecular motors that digest their track to rectify Brownian motion: processive movement of exonuclease enzymes

International Nuclear Information System (INIS)

Xie Ping

2009-01-01

A general model is presented for the processive movement of molecular motors such as λ-exonuclease, RecJ and exonuclease I that use digestion of a DNA track to rectify Brownian motion along this track. Using this model, the translocation dynamics of these molecular motors is studied. The sequence-dependent pausing of λ-exonuclease, which results from a site-specific high affinity DNA interaction, is also studied. The theoretical results are consistent with available experimental data. Moreover, the model is used to predict the lifetime distribution and force dependence of these paused states.

Beneficial liaisons: radiobiology meets cellular and molecular biology

International Nuclear Information System (INIS)

Stevenson, Mary Ann; Coleman, C. Norman

1995-01-01

Purpose: The purpose of this course is to familiarize radiation oncologists with the concepts and terminology and molecular and cellular biology that are especially relevant to radiation oncology. The ability of radiation oncologists to remain current with the new discoveries of modern biology is essential to the development of improved therapeutic strategies and, importantly, to the proper balance between investment in technology and biology. Objective: This year, this Refresher Course is part of a three-part ''series'' including Drs. Martin Brown and Amato Giaccia. The objective is to provide continuing education for the academic and practicing radiation oncologist, physicist and biologist in the modern biologic concepts of cancer and its treatment. An effort will be made to relate these general concepts to the clinic by providing a broad view as to potential new biological treatments which might enhance the efficacy of radiation therapy. The specific focus of this Course will vary from year to year. Some of the classic radiation biology models which form the basis of clinical practice and laboratory research will be examined and 'newer' models will be presented which take into account the emerging knowledge of cellular and molecular biology. A few techniques in molecular and cellular biology will be described to the extent necessary to understand their basic concepts and their applicability. Aspects of radiation biology which will be covered include cell cycle, radiation-induced changes in the cellular phenotype, and considerations of the effect of the tumor microenvironment. It is not the expectation that the attendees will become experts in the particular subjects presented. Rather, it is the intent to increase their curiosity as to the new knowledge that is emerging and to demonstrate that these seemingly complicated areas can be understood and appreciated with a modicum of the effort

pGLO Mutagenesis: A Laboratory Procedure in Molecular Biology for Biology Students

Science.gov (United States)

Bassiri, Eby A.

2011-01-01

A five-session laboratory project was designed to familiarize or increase the laboratory proficiency of biology students and others with techniques and instruments commonly used in molecular biology research laboratories and industries. In this project, the EZ-Tn5 transposon is used to generate and screen a large number of cells transformed with…

The role and future of in-vitro isotopic techniques in molecular biology

International Nuclear Information System (INIS)

Dar, L.; Khan, B.K.

2004-01-01

In this review we discuss isotopic in-vitro molecular biology techniques, and their advantages and applications. Isotopic methods have helped to shape molecular biology since its early days. Despite the availability of non-isotopic alternatives, isotopic methods continue to be used in molecular biology due to certain advantages, especially related to sensitivity and cost-effectiveness. Numerous techniques involving the use of isotopes help in the characterization of genes, including the detection of single nucleotide polymorphisms (SNPs) or mutations. Other isotopic molecular methods are utilized to study the phenotypic expression of gene sequences and their mutation. Emerging branches of molecular biology like functional genomics and proteomics are extremely important for exploiting the rapidly growing data derived from whole genomic sequencing of human and microbial genomes. Recent molecular biology applications like the high-throughput array techniques are relevant in the context of both structural and functional genomics. In proteomics, stable isotope based technology has found applications in the analysis of protein structure and interactions. (author)

Thermal E/ Z Isomerization in First Generation Molecular Motors.

Science.gov (United States)

Kuwahara, Shunsuke; Suzuki, Yuri; Sugita, Naoya; Ikeda, Mari; Nagatsugi, Fumi; Harada, Nobuyuki; Habata, Yoichi

2018-04-20

Determination of a thermal E/ Z isomerization barrier of first generation molecular motors is reported. Stable ( E)-1a directly converts to stable ( Z)-1c without photochemical E/ Z isomerization. The activation Gibbs energy of the isomerization was determined to be 123 kJ mol -1 by circular dichroism spectral changes. Density functional theory calculations show that ( Z)-1c is ∼11.4 kJ mol -1 more stable than ( E)-1a.

European Conference on Molecular Biology EMBO

CERN Multimedia

1967-01-01

European Conference on Molecular Biology, which eventually led to the setting up of EMBO, was held at CERN in April. Olivier Reverdin is adressing the delegates. Bernard Gregory is on the left and Willy Spuhler in the centre.

Molecular Biology and Prevention of Endometrial Cancer

National Research Council Canada - National Science Library

Maxwell, George L

2006-01-01

To increase our understanding of the molecular aberrations associated with endometrial carcinogenesis and the biologic mechanisms underlying the protective effect of oral contraceptive (OC) therapy. 1...

Molecular Biology and Prevention of Endometrial Cancer

National Research Council Canada - National Science Library

Maxwell, George

2003-01-01

To increase our understanding of the molecular aberrations associated with endometrial carcinogenesis and the biologic mechanisms underlying the protective effect of oral contraceptive therapy. Methods: 1...

Molecular Biology and Prevention of Endometrial Cancer

National Research Council Canada - National Science Library

Maxwell, George L

2004-01-01

To increase our understanding of the molecular aberrations associated with endometrial carcinogenesis and the biologic mechanisms underlying the protective effect of oral contraceptive therapy. Methods: 1...

Micropropagation, genetic engineering, and molecular biology of Populus

Science.gov (United States)

N. B. Klopfenstein; Y. W. Chun; M. -S. Kim; M. A. Ahuja; M. C. Dillon; R. C. Carman; L. G. Eskew

1997-01-01

Thirty-four Populus biotechnology chapters, written by 85 authors, are comprised in 5 sections: 1) in vitro culture (micropropagation, somatic embryogenesis, protoplasts, somaclonal variation, and germplasm preservation); 2) transformation and foreign gene expression; 3) molecular biology (molecular/genetic characterization); 4) biotic and abiotic resistance (disease,...

Frontiers of NMR in Molecular Biology

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-08-25

NMR spectroscopy is expanding the horizons of structural biology by determining the structures and describing the dynamics of blobular proteins in aqueous solution, as well as other classes of proteins including membrane proteins and the polypeptides that form the aggregates diagnostic of prion and amyloid diseases. Significant results are also emerging on DNA and RNA oligomers and their complexes with proteins. This meeting focused attention on key structural questions emanating from molecular biology and how NMR spectroscopy can be used to answer them.

Simple Calculation Programs for Biology Methods in Molecular ...

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Simple Calculation Programs for Biology Methods in Molecular Biology. GMAP: A program for mapping potential restriction sites. RE sites in ambiguous and non-ambiguous DNA sequence; Minimum number of silent mutations required for introducing a RE sites; Set ...

Artificial muscle-like function from hierarchical supramolecular assembly of photoresponsive molecular motors

NARCIS (Netherlands)

Chen, Jiawen; Leung, Franco King-Chi; Stuart, Marc C A; Kajitani, Takashi; Fukushima, Takanori; van der Giessen, Erik; Feringa, Ben L

A striking feature of living systems is their ability to produce motility by amplification of collective molecular motion from the nanoscale up to macroscopic dimensions. Some of nature's protein motors, such as myosin in muscle tissue, consist of a hierarchical supramolecular assembly of very large

Macroscopic transport by synthetic molecular machines

NARCIS (Netherlands)

Berna, J; Leigh, DA; Lubomska, M; Mendoza, SM; Perez, EM; Rudolf, P; Teobaldi, G; Zerbetto, F

Nature uses molecular motors and machines in virtually every significant biological process, but demonstrating that simpler artificial structures operating through the same gross mechanisms can be interfaced with - and perform physical tasks in - the macroscopic world represents a significant hurdle

tRNA--the golden standard in molecular biology.

Science.gov (United States)

Barciszewska, Mirosława Z; Perrigue, Patrick M; Barciszewski, Jan

2016-01-01

Transfer RNAs (tRNAs) represent a major class of RNA molecules. Their primary function is to help decode a messenger RNA (mRNA) sequence in order to synthesize protein and thus ensures the precise translation of genetic information that is imprinted in DNA. The discovery of tRNA in the late 1950's provided critical insight into a genetic machinery when little was known about the central dogma of molecular biology. In 1965, Robert Holley determined the first nucleotide sequence of alanine transfer RNA (tRNA(Ala)) which earned him the 1968 Nobel Prize in Physiology or Medicine. Today, tRNA is one of the best described and characterized biological molecules. Here we review some of the key historical events in tRNA research which led to breakthrough discoveries and new developments in molecular biology.

The Central Dogma of Molecular Biology

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 3. The Central Dogma of Molecular Biology - A Retrospective after Fifty Years. Michel Morange. General Article Volume 14 Issue 3 March 2009 pp 236-247. Fulltext. Click here to view fulltext PDF. Permanent link:

Current dichotomy between traditional molecular biological and omic research in cancer biology and pharmacology.

Science.gov (United States)

Reinhold, William C

2015-12-10

There is currently a split within the cancer research community between traditional molecular biological hypothesis-driven and the more recent "omic" forms or research. While the molecular biological approach employs the tried and true single alteration-single response formulations of experimentation, the omic employs broad-based assay or sample collection approaches that generate large volumes of data. How to integrate the benefits of these two approaches in an efficient and productive fashion remains an outstanding issue. Ideally, one would merge the understandability, exactness, simplicity, and testability of the molecular biological approach, with the larger amounts of data, simultaneous consideration of multiple alterations, consideration of genes both of known interest along with the novel, cross-sample comparisons among cell lines and patient samples, and consideration of directed questions while simultaneously gaining exposure to the novel provided by the omic approach. While at the current time integration of the two disciplines remains problematic, attempts to do so are ongoing, and will be necessary for the understanding of the large cell line screens including the Developmental Therapeutics Program's NCI-60, the Broad Institute's Cancer Cell Line Encyclopedia, and the Wellcome Trust Sanger Institute's Cancer Genome Project, as well as the the Cancer Genome Atlas clinical samples project. Going forward there is significant benefit to be had from the integration of the molecular biological and the omic forms or research, with the desired goal being improved translational understanding and application.

How molecular motors are arranged on a cargo is important for vesicular transport.

Directory of Open Access Journals (Sweden)

Robert P Erickson

2011-05-01

Full Text Available The spatial organization of the cell depends upon intracellular trafficking of cargos hauled along microtubules and actin filaments by the molecular motor proteins kinesin, dynein, and myosin. Although much is known about how single motors function, there is significant evidence that cargos in vivo are carried by multiple motors. While some aspects of multiple motor function have received attention, how the cargo itself--and motor organization on the cargo--affects transport has not been considered. To address this, we have developed a three-dimensional Monte Carlo simulation of motors transporting a spherical cargo, subject to thermal fluctuations that produce both rotational and translational diffusion. We found that these fluctuations could exert a load on the motor(s, significantly decreasing the mean travel distance and velocity of large cargos, especially at large viscosities. In addition, the presence of the cargo could dramatically help the motor to bind productively to the microtubule: the relatively slow translational and rotational diffusion of moderately sized cargos gave the motors ample opportunity to bind to a microtubule before the motor/cargo ensemble diffuses out of range of that microtubule. For rapidly diffusing cargos, the probability of their binding to a microtubule was high if there were nearby microtubules that they could easily reach by translational diffusion. Our simulations found that one reason why motors may be approximately 100 nm long is to improve their 'on' rates when attached to comparably sized cargos. Finally, our results suggested that to efficiently regulate the number of active motors, motors should be clustered together rather than spread randomly over the surface of the cargo. While our simulation uses the specific parameters for kinesin, these effects result from generic properties of the motors, cargos, and filaments, so they should apply to other motors as well.

Bio-hybrid micro/nanodevices powered by flagellar motor: challenges and strategies

Directory of Open Access Journals (Sweden)

Jin-Woo eKim

2015-07-01

Full Text Available Molecular motors, which are precision-engineered by nature, offer exciting possibilities for bio-hybrid engineered systems. They could enable real applications ranging from micro/nano fluidics, to biosensing, to medical diagnoses. This review describes the fundamental biological insights and fascinating potentials of these remarkable sensing and actuation machines, in particular bacterial flagellar motors, as well as their engineering perspectives with regard to applications in bio-engineered hybrid systems and nanobiotechnology.

Conformational dynamics of ATP/Mg:ATP in motor proteins via data mining and molecular simulation

Science.gov (United States)

Bojovschi, A.; Liu, Ming S.; Sadus, Richard J.

2012-08-01

The conformational diversity of ATP/Mg:ATP in motor proteins was investigated using molecular dynamics and data mining. Adenosine triphosphate (ATP) conformations were found to be constrained mostly by inter cavity motifs in the motor proteins. It is demonstrated that ATP favors extended conformations in the tight pockets of motor proteins such as F1-ATPase and actin whereas compact structures are favored in motor proteins such as RNA polymerase and DNA helicase. The incorporation of Mg2+ leads to increased flexibility of ATP molecules. The differences in the conformational dynamics of ATP/Mg:ATP in various motor proteins was quantified by the radius of gyration. The relationship between the simulation results and those obtained by data mining of motor proteins available in the protein data bank is analyzed. The data mining analysis of motor proteins supports the conformational diversity of the phosphate group of ATP obtained computationally.

Genetics and molecular biology of breast cancer

Energy Technology Data Exchange (ETDEWEB)

King, M.C. [California Univ., Berkeley, CA (United States); Lippman, M. [Georgetown Univ. Medical Center, Washington, DC (United States)] [comps.

1992-12-31

This volume contains the abstracts of oral presentations and poster sessions presented at the Cold Springs Harbor Meeting on Cancer Cells, this meeting entitled Genetics and Molecular Biology of Breast Cancer.

Barrett's esophagus: cancer and molecular biology

NARCIS (Netherlands)

Gibson, Michael K.; Dhaliwal, Arashinder S.; Clemons, Nicholas J.; Phillips, Wayne A.; Dvorak, Katerina; Tong, Daniel; Law, Simon; Pirchi, E. Daniel; Räsänen, Jari; Krasna, Mark J.; Parikh, Kaushal; Krishnadath, Kausilia K.; Chen, Yu; Griffiths, Leonard; Colleypriest, Benjamin J.; Farrant, J. Mark; Tosh, David; Das, Kiron M.; Bajpai, Manisha

2013-01-01

The following paper on the molecular biology of Barrett's esophagus (BE) includes commentaries on signaling pathways central to the development of BE including Hh, NF-κB, and IL-6/STAT3; surgical approaches for esophagectomy and classification of lesions by appropriate therapy; the debate over the

Bioenergetics molecular biology, biochemistry, and pathology

CERN Document Server

Ozawa, Takayuki

1990-01-01

The emergence of the Biochemical Sciences is underlined by the FAOB symposium in Seoul and highlighted by this Satellite meeting on the "New Bioenergetics. " Classical mitochondrial electron transfer and energy coupling is now complemented by the emerging molecular biology of the respiratory chain which is studied hand in hand with the recognition of mitochondrial disease as a major and emerging study in the basic and clinical medical sciences. Thus, this symposium has achieved an important balance of the fundamental and applied aspects of bioenergetics in the modern setting of molecular biology and mitochondrial disease. At the same time, the symposium takes note not only of the emerging excellence of Biochemical Studies in the Orient and indeed in Korea itself, but also retrospectively enjoys the history of electron transport and energy conservation as represented by the triumvirate ofYagi, King and Slater. Many thanks are due Drs. Kim and Ozawa for their elegant organization of this meeting and its juxtapo...

Detectable states, cycle fluxes, and motility scaling of molecular motor kinesin: An integrative kinetic graph theory analysis

Science.gov (United States)

Ren, Jie

2017-12-01

The process by which a kinesin motor couples its ATPase activity with concerted mechanical hand-over-hand steps is a foremost topic of molecular motor physics. Two major routes toward elucidating kinesin mechanisms are the motility performance characterization of velocity and run length, and single-molecular state detection experiments. However, these two sets of experimental approaches are largely uncoupled to date. Here, we introduce an integrative motility state analysis based on a theorized kinetic graph theory for kinesin, which, on one hand, is validated by a wealth of accumulated motility data, and, on the other hand, allows for rigorous quantification of state occurrences and chemomechanical cycling probabilities. An interesting linear scaling for kinesin motility performance across species is discussed as well. An integrative kinetic graph theory analysis provides a powerful tool to bridge motility and state characterization experiments, so as to forge a unified effort for the elucidation of the working mechanisms of molecular motors.

Molecular profiles to biology and pathways: a systems biology approach.

Science.gov (United States)

Van Laere, Steven; Dirix, Luc; Vermeulen, Peter

2016-06-16

Interpreting molecular profiles in a biological context requires specialized analysis strategies. Initially, lists of relevant genes were screened to identify enriched concepts associated with pathways or specific molecular processes. However, the shortcoming of interpreting gene lists by using predefined sets of genes has resulted in the development of novel methods that heavily rely on network-based concepts. These algorithms have the advantage that they allow a more holistic view of the signaling properties of the condition under study as well as that they are suitable for integrating different data types like gene expression, gene mutation, and even histological parameters.

[The molecular biology of epithelial ovarian cancer].

Science.gov (United States)

Leary, Alexandra; Pautier, Patricia; Tazi, Youssef; Morice, Philippe; Duvillard, Pierre; Gouy, Sébastien; Uzan, Catherine; Gauthier, Hélène; Balleyguier, Corinne; Lhommé, Catherine

2012-12-01

Epithelial ovarian cancer frequently presents at an advanced stage where the cornerstone of management remains surgery and platinum-based chemotherapy. Unfortunately, despite sometimes dramatic initial responses, advanced ovarian cancer almost invariably relapses. Little progress has been made in the identification of effective targeted-therapies for ovarian cancer. The majority of clinical trials investigating novel agents have been negative and the only approved targeted-therapy is bevacizumab, for which reliable predictive biomarkers still elude us. Ovarian cancer is treated as a uniform disease. Yet, biological studies have highlighted the heterogeneity of this malignancy with marked differences in histology, oncogenesis, prognosis, chemo-responsiveness, and molecular profile. Recent high throughput molecular analyses have identified a huge number of genomic/phenotypic alterations. Broadly speaking, high grade serous carcinomas (type II) display significant genomic instability and numerous amplifications and losses; low grade (type I) tumors are genomically stable but display frequent mutations. Importantly, many of these genomic alterations relate to known oncogenes for which targeted-therapies are available or in development. There is today a real potential for personalized medicine in ovarian cancer. We will review the current literature regarding the molecular characterization of epithelial ovarian cancer and discuss the biological rationale for a number of targeted strategies. In order to translate these biological advances into meaningful clinical improvements for our patients, it is imperative to incorporate translational research in ovarian cancer trials, a number of strategies will be proposed such as the acquisition of quality tumor samples, including sequential pre- and post-treatment biopsies, the potential of liquid biopsies, and novel trial designs more adapted to the molecular era of ovarian cancer research.

Molecular beam sampling from a rocket-motor combustion chamber

International Nuclear Information System (INIS)

Houseman, John; Young, W.S.

1974-01-01

A molecular-beam mass-spectrometer sampling apparatus has been developed to study the reactive species concentrations as a function of position in a rocket-motor combustion chamber. Unique design features of the sampling system include (a) the use of a multiple-nozzle end plate for preserving the nonuniform properties of the flow field inside the combustion chamber, (b) the use of a water-injection heat shield, and (c) the use of a 300 CFM mechanical pump for the first vacuum stage (eliminating the use of a huge conventional oil booster pump). Preliminary rocket-motor tests have been performed using the highly reactive propellants nitrogen tetroxide/hydrazine (N 2 O 4 /N 2 H 4 ) at an oxidizer/fuel ratio of 1.2 by weight. The combustion-chamber pressure is approximately 60psig. Qualitative results on unreacted oxidizer/fuel ratio, relative abundance of oxidizer and fuel fragments, and HN 3 distribution across the chamber are presented

The molecular biology of ilarviruses.

Science.gov (United States)

Pallas, Vicente; Aparicio, Frederic; Herranz, Mari C; Sanchez-Navarro, Jesus A; Scott, Simon W

2013-01-01

Ilarviruses were among the first 16 groups of plant viruses approved by ICTV. Like Alfalfa mosaic virus (AMV), bromoviruses, and cucumoviruses they are isometric viruses and possess a single-stranded, tripartite RNA genome. However, unlike these other three groups, ilarviruses were recognized as being recalcitrant subjects for research (their ready lability is reflected in the sigla used to create the group name) and were renowned as unpromising subjects for the production of antisera. However, it was recognized that they shared properties with AMV when the phenomenon of genome activation, in which the coat protein (CP) of the virus is required to be present to initiate infection, was demonstrated to cross group boundaries. The CP of AMV could activate the genome of an ilarvirus and vice versa. Development of the molecular information for ilarviruses lagged behind the knowledge available for the more extensively studied AMV, bromoviruses, and cucumoviruses. In the past 20 years, genomic data for most known ilarviruses have been developed facilitating their detection and allowing the factors involved in the molecular biology of the genus to be investigated. Much information has been obtained using Prunus necrotic ringspot virus and the more extensively studied AMV. A relationship between some ilarviruses and the cucumoviruses has been defined with the recognition that members of both genera encode a 2b protein involved in RNA silencing and long distance viral movement. Here, we present a review of the current knowledge of both the taxonomy and the molecular biology of this genus of agronomically and horticulturally important viruses. Copyright © 2013 Elsevier Inc. All rights reserved.

Mechanical design of translocating motor proteins.

Science.gov (United States)

Hwang, Wonmuk; Lang, Matthew J

2009-01-01

Translocating motors generate force and move along a biofilament track to achieve diverse functions including gene transcription, translation, intracellular cargo transport, protein degradation, and muscle contraction. Advances in single molecule manipulation experiments, structural biology, and computational analysis are making it possible to consider common mechanical design principles of these diverse families of motors. Here, we propose a mechanical parts list that include track, energy conversion machinery, and moving parts. Energy is supplied not just by burning of a fuel molecule, but there are other sources or sinks of free energy, by binding and release of a fuel or products, or similarly between the motor and the track. Dynamic conformational changes of the motor domain can be regarded as controlling the flow of free energy to and from the surrounding heat reservoir. Multiple motor domains are organized in distinct ways to achieve motility under imposed physical constraints. Transcending amino acid sequence and structure, physically and functionally similar mechanical parts may have evolved as nature's design strategy for these molecular engines.

[Progress in molecular biology of a semi-mangrove, Millettia pinnata].

Science.gov (United States)

Huang, Jianzi; Zhang, Wanke; Huang, Rongfeng; Zheng, Yizhi

2015-04-01

Millettia pinnata L. is a leguminous tree with great potential in biodiesel applications and also a typical semi-mangrove. In this review, we presented several aspects about the recent research progress in molecular biology of M. pinnata. We descrived several types of molecular markers used to assess the genetic diversity and phylogeny of this species, genome and transcriptome analyses based on high-throughput sequencing platform accomplished for this species, and several gene and genomic sequences of this species isolated for further research. Finally, based on the current research progress, we proposed some orientations for future molecular biology research on M. pinnata.

Systematic Representation of Molecular Biology Knowledge.

Science.gov (United States)

Fisher, Kathleen M.

A small set of relationships has been identified which appears to be sufficient for describing all molecular and cellular reactions and structures discussed in an introductory biology course. A precise definition has been developed for each relationship. These 20 relationships are of four types: (1) analytical; (2) spatial; (3) temporal; and (4)…

Molecular biology of potyviruses.

Science.gov (United States)

Revers, Frédéric; García, Juan Antonio

2015-01-01

Potyvirus is the largest genus of plant viruses causing significant losses in a wide range of crops. Potyviruses are aphid transmitted in a nonpersistent manner and some of them are also seed transmitted. As important pathogens, potyviruses are much more studied than other plant viruses belonging to other genera and their study covers many aspects of plant virology, such as functional characterization of viral proteins, molecular interaction with hosts and vectors, structure, taxonomy, evolution, epidemiology, and diagnosis. Biotechnological applications of potyviruses are also being explored. During this last decade, substantial advances have been made in the understanding of the molecular biology of these viruses and the functions of their various proteins. After a general presentation on the family Potyviridae and the potyviral proteins, we present an update of the knowledge on potyvirus multiplication, movement, and transmission and on potyvirus/plant compatible interactions including pathogenicity and symptom determinants. We end the review providing information on biotechnological applications of potyviruses. © 2015 Elsevier Inc. All rights reserved.

A decade of molecular cell biology: achievements and challenges.

Science.gov (United States)

Akhtar, Asifa; Fuchs, Elaine; Mitchison, Tim; Shaw, Reuben J; St Johnston, Daniel; Strasser, Andreas; Taylor, Susan; Walczak, Claire; Zerial, Marino

2011-09-23

Nature Reviews Molecular Cell Biology celebrated its 10-year anniversary during this past year with a series of specially commissioned articles. To complement this, here we have asked researchers from across the field for their insights into how molecular cell biology research has evolved during this past decade, the key concepts that have emerged and the most promising interfaces that have developed. Their comments highlight the broad impact that particular advances have had, some of the basic understanding that we still require, and the collaborative approaches that will be essential for driving the field forward.

Adiabatic and non-adiabatic charge pumping in a single-level molecular motor

NARCIS (Netherlands)

Napitu, B.D.; Thijssen, J.M.

2015-01-01

We propose a design for realizing quantum charge pump based on a recent proposal for a molecular motor (Seldenthuis J S et al 2010 ACS Nano 4 6681). Our design is based on the presence of a moiety with a permanent dipole moment which can rotate, thereby modulating the couplings to metallic contacts

Grete Kellenberger-Gujer: Molecular biology research pioneer.

Science.gov (United States)

Citi, Sandra; Berg, Douglas E

2016-01-01

Grete Kellenberger-Gujer was a Swiss molecular biologist who pioneered fundamental studies of bacteriophage in the mid-20(th) century at the University of Geneva. Her life and career stories are reviewed here, focusing on her fundamental contributions to our early understanding of phage biology via her insightful analyses of phenomena such as the lysogenic state of a temperate phage (λ), genetic recombination, radiation's in vivo consequences, and DNA restriction-modification; on her creative personality and interactions with peers; and how her academic advancement was affected by gender, societal conditions and cultural attitudes of the time. Her story is important scientifically, putting into perspective features of the scientific community from just before the molecular biology era started through its early years, and also sociologically, in illustrating the numerous "glass ceilings" that, especially then, often hampered the advancement of creative women.

Digital learning material for experimental design and model building in molecular biology

NARCIS (Netherlands)

Aegerter-Wilmsen, T.

2005-01-01

Designing experimental approaches is a major cognitive skill in molecular biology research, and building models, including quantitative ones, is a cognitive skill which is rapidly gaining importance. Since molecular biology education at university level is aimed at educating future researchers, we

Information theory in molecular biology

OpenAIRE

Adami, Christoph

2004-01-01

This article introduces the physics of information in the context of molecular biology and genomics. Entropy and information, the two central concepts of Shannon's theory of information and communication, are often confused with each other but play transparent roles when applied to statistical ensembles (i.e., identically prepared sets) of symbolic sequences. Such an approach can distinguish between entropy and information in genes, predict the secondary structure of ribozymes, and detect the...

The extracellular matrix of plants: Molecular, cellular and developmental biology

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-31

A symposium entitled ``The Extracellular Matrix of Plants: Molecular, Cellular and Developmental Biology was held in Tamarron, Colorado, March 15--21, 1996. The following topics were explored in addresses by 43 speakers: structure and biochemistry of cell walls; biochemistry, molecular biology and biosynthesis of lignin; secretory pathway and synthesis of glycoproteins; biosynthesis of matrix polysaccharides, callose and cellulose; role of the extracellular matrix in plant growth and development; plant cell walls in symbiosis and pathogenesis.

QTAIM and Stress Tensor Characterization of Intramolecular Interactions Along Dynamics Trajectories of a Light-Driven Rotary Molecular Motor.

Science.gov (United States)

Wang, Lingling; Huan, Guo; Momen, Roya; Azizi, Alireza; Xu, Tianlv; Kirk, Steven R; Filatov, Michael; Jenkins, Samantha

2017-06-29

A quantum theory of atoms in molecules (QTAIM) and stress tensor analysis was applied to analyze intramolecular interactions influencing the photoisomerization dynamics of a light-driven rotary molecular motor. For selected nonadiabatic molecular dynamics trajectories characterized by markedly different S 1 state lifetimes, the electron densities were obtained using the ensemble density functional theory method. The analysis revealed that torsional motion of the molecular motor blades from the Franck-Condon point to the S 1 energy minimum and the S 1 /S 0 conical intersection is controlled by two factors: greater numbers of intramolecular bonds before the hop-time and unusually strongly coupled bonds between the atoms of the rotor and the stator blades. This results in the effective stalling of the progress along the torsional path for an extended period of time. This finding suggests a possibility of chemical tuning of the speed of photoisomerization of molecular motors and related molecular switches by reshaping their molecular backbones to decrease or increase the degree of coupling and numbers of intramolecular bond critical points as revealed by the QTAIM/stress tensor analysis of the electron density. Additionally, the stress tensor scalar and vector analysis was found to provide new methods to follow the trajectories, and from this, new insight was gained into the behavior of the S 1 state in the vicinity of the conical intersection.

Molecular Biology and Prevention of Endometrial Cancer. Addendum

National Research Council Canada - National Science Library

Maxwell, George L

2008-01-01

Objective: To increase our understanding of the molecular aberrations associated with endometrial carcinogenesis and the biologic mechanisms underlying the protective effect of oral contraceptive (OC) therapy. Methods: 1...

Dualities in the analysis of phage DNA packaging motors

Science.gov (United States)

Serwer, Philip; Jiang, Wen

2012-01-01

The DNA packaging motors of double-stranded DNA phages are models for analysis of all multi-molecular motors and for analysis of several fundamental aspects of biology, including early evolution, relationship of in vivo to in vitro biochemistry and targets for anti-virals. Work on phage DNA packaging motors both has produced and is producing dualities in the interpretation of data obtained by use of both traditional techniques and the more recently developed procedures of single-molecule analysis. The dualities include (1) reductive vs. accretive evolution, (2) rotation vs. stasis of sub-assemblies of the motor, (3) thermal ratcheting vs. power stroking in generating force, (4) complete motor vs. spark plug role for the packaging ATPase, (5) use of previously isolated vs. new intermediates for analysis of the intermediate states of the motor and (6) a motor with one cycle vs. a motor with two cycles. We provide background for these dualities, some of which are under-emphasized in the literature. We suggest directions for future research. PMID:23532204

Connecting Biology to Electronics: Molecular Communication via Redox Modality.

Science.gov (United States)

Liu, Yi; Li, Jinyang; Tschirhart, Tanya; Terrell, Jessica L; Kim, Eunkyoung; Tsao, Chen-Yu; Kelly, Deanna L; Bentley, William E; Payne, Gregory F

2017-12-01

Biology and electronics are both expert at for accessing, analyzing, and responding to information. Biology uses ions, small molecules, and macromolecules to receive, analyze, store, and transmit information, whereas electronic devices receive input in the form of electromagnetic radiation, process the information using electrons, and then transmit output as electromagnetic waves. Generating the capabilities to connect biology-electronic modalities offers exciting opportunities to shape the future of biosensors, point-of-care medicine, and wearable/implantable devices. Redox reactions offer unique opportunities for bio-device communication that spans the molecular modalities of biology and electrical modality of devices. Here, an approach to search for redox information through an interactive electrochemical probing that is analogous to sonar is adopted. The capabilities of this approach to access global chemical information as well as information of specific redox-active chemical entities are illustrated using recent examples. An example of the use of synthetic biology to recognize external molecular information, process this information through intracellular signal transduction pathways, and generate output responses that can be detected by electrical modalities is also provided. Finally, exciting results in the use of redox reactions to actuate biology are provided to illustrate that synthetic biology offers the potential to guide biological response through electrical cues. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Recommendations for accreditation of laboratories in molecular biology of hematologic malignancies.

Science.gov (United States)

Flandrin-Gresta, Pascale; Cornillet, Pascale; Hayette, Sandrine; Gachard, Nathalie; Tondeur, Sylvie; Mauté, Carole; Cayuela, Jean-Michel

2015-01-01

Over recent years, the development of molecular biology techniques has improved the hematological diseases diagnostic and follow-up. Consequently, these techniques are largely used in the biological screening of these diseases; therefore the Hemato-oncology molecular diagnostics laboratories must be actively involved in the accreditation process according the ISO 15189 standard. The French group of molecular biologists (GBMHM) provides requirements for the implementation of quality assurance for the medical molecular laboratories. This guideline states the recommendations for the pre-analytical, analytical (methods validation procedures, quality controls, reagents), and post-analytical conditions. In addition, herein we state a strategy for the internal quality control management. These recommendations will be regularly updated.

Molecular knots in biology and chemistry

International Nuclear Information System (INIS)

Lim, Nicole C H; Jackson, Sophie E

2015-01-01

Knots and entanglements are ubiquitous. Beyond their aesthetic appeal, these fascinating topological entities can be either useful or cumbersome. In recent decades, the importance and prevalence of molecular knots have been increasingly recognised by scientists from different disciplines. In this review, we provide an overview on the various molecular knots found in naturally occurring biological systems (DNA, RNA and proteins), and those created by synthetic chemists. We discuss the current knowledge in these fields, including recent developments in experimental and, in some cases, computational studies which are beginning to shed light into the complex interplay between the structure, formation and properties of these topologically intricate molecules. (paper)

Molecular Biology of Pancreatic Cancer: How Useful Is It in Clinical Practice?

OpenAIRE

George H Sakorafas; Vasileios Smyrniotis

2012-01-01

Context During the recent two decades dramatic advances of molecular biology allowed an in-depth understanding of pancreatic carcinogenesis. It is currently accepted that pancreatic cancer has a genetic component. The real challenge is now how these impressive advances could be used in clinical practice. Objective To critically present currently available data regarding clinical application of molecular biology in pancreatic cancer. Methods Reports about clinical implications of molecular bio...

Genomic Signal Processing: Predicting Basic Molecular Biological Principles

Science.gov (United States)

Alter, Orly

2005-03-01

Advances in high-throughput technologies enable acquisition of different types of molecular biological data, monitoring the flow of biological information as DNA is transcribed to RNA, and RNA is translated to proteins, on a genomic scale. Future discovery in biology and medicine will come from the mathematical modeling of these data, which hold the key to fundamental understanding of life on the molecular level, as well as answers to questions regarding diagnosis, treatment and drug development. Recently we described data-driven models for genome-scale molecular biological data, which use singular value decomposition (SVD) and the comparative generalized SVD (GSVD). Now we describe an integrative data-driven model, which uses pseudoinverse projection (1). We also demonstrate the predictive power of these matrix algebra models (2). The integrative pseudoinverse projection model formulates any number of genome-scale molecular biological data sets in terms of one chosen set of data samples, or of profiles extracted mathematically from data samples, designated the ``basis'' set. The mathematical variables of this integrative model, the pseudoinverse correlation patterns that are uncovered in the data, represent independent processes and corresponding cellular states (such as observed genome-wide effects of known regulators or transcription factors, the biological components of the cellular machinery that generate the genomic signals, and measured samples in which these regulators or transcription factors are over- or underactive). Reconstruction of the data in the basis simulates experimental observation of only the cellular states manifest in the data that correspond to those of the basis. Classification of the data samples according to their reconstruction in the basis, rather than their overall measured profiles, maps the cellular states of the data onto those of the basis, and gives a global picture of the correlations and possibly also causal coordination of

Molecular and biological interactions in colorectal cancer

NARCIS (Netherlands)

Heer, Pieter de

2007-01-01

The current thesis discusses the use of molecular and biological tumor markers to predict clinical outcome. By studying several key processes in the develepment of cancer as regulation of cell motility (non-receptor protein tyrosin adesion kinases, FAK, Src and paxillin, Apoptosis (caspase-3

Can molecular cell biology explain chromosome motions?

Directory of Open Access Journals (Sweden)

Gagliardi L

2011-05-01

Full Text Available Abstract Background Mitotic chromosome motions have recently been correlated with electrostatic forces, but a lingering "molecular cell biology" paradigm persists, proposing binding and release proteins or molecular geometries for force generation. Results Pole-facing kinetochore plates manifest positive charges and interact with negatively charged microtubule ends providing the motive force for poleward chromosome motions by classical electrostatics. This conceptual scheme explains dynamic tracking/coupling of kinetochores to microtubules and the simultaneous depolymerization of kinetochore microtubules as poleward force is generated. Conclusion We question here why cells would prefer complex molecular mechanisms to move chromosomes when direct electrostatic interactions between known bound charge distributions can accomplish the same task much more simply.

Quantum control of a chiral molecular motor driven by femtosecond laser pulses: Mechanisms of regular and reverse rotations

International Nuclear Information System (INIS)

Yamaki, M.; Hoki, K.; Kono, H.; Fujimura, Y.

2008-01-01

Rotational mechanisms of a chiral molecular motor driven by femtosecond laser pulses were investigated on the basis of results of a quantum control simulation. A chiral molecule, (R)-2-methyl-cyclopenta-2,4-dienecarboaldehyde, was treated as a molecular motor within a one-dimensional model. It was assumed that the motor is fixed on a surface and driven in the low temperature limit. Electric fields of femtosecond laser pulses driving both regular rotation of the molecular motor with a plus angular momentum and reverse rotation with a minus one were designed by using a global control method. The mechanism of the regular rotation is similar to that obtained by a conventional pump-dump pulse method: the direction of rotation is the same as that of the initial wave packet propagation on the potential surface of the first singlet (nπ*) excited state S 1 . A new control mechanism has been proposed for the reverse rotation that cannot be driven by a simple pump-dump pulse method. In this mechanism, a coherent Stokes pulse creates a wave packet localized on the ground state potential surface in the right hand side. The wave packet has a negative angular momentum to drive reverse rotation at an early time

Molecular biology approaches in bioadhesion research

Directory of Open Access Journals (Sweden)

Marcelo Rodrigues

2014-07-01

Full Text Available The use of molecular biology tools in the field of bioadhesion is still in its infancy. For new research groups who are considering taking a molecular approach, the techniques presented here are essential to unravelling the sequence of a gene, its expression and its biological function. Here we provide an outline for addressing adhesion-related genes in diverse organisms. We show how to gradually narrow down the number of candidate transcripts that are involved in adhesion by (1 generating a transcriptome and a differentially expressed cDNA list enriched for adhesion-related transcripts, (2 setting up a BLAST search facility, (3 perform an in situ hybridization screen, and (4 functional analyses of selected genes by using RNA interference knock-down. Furthermore, latest developments in genome-editing are presented as new tools to study gene function. By using this iterative multi-technologies approach, the identification, isolation, expression and function of adhesion-related genes can be studied in most organisms. These tools will improve our understanding of the diversity of molecules used for adhesion in different organisms and these findings will help to develop innovative bio-inspired adhesives.

Applications of neutron scattering in molecular biological research

International Nuclear Information System (INIS)

Nierhaus, K.H.

1984-01-01

The study of the molecular structure of biological materials by neutron scattering is described. As example the results of the study of the components of a ribosome of Escherichia coli are presented. (HSI) [de

Time scale of diffusion in molecular and cellular biology

International Nuclear Information System (INIS)

Holcman, D; Schuss, Z

2014-01-01

Diffusion is the driver of critical biological processes in cellular and molecular biology. The diverse temporal scales of cellular function are determined by vastly diverse spatial scales in most biophysical processes. The latter are due, among others, to small binding sites inside or on the cell membrane or to narrow passages between large cellular compartments. The great disparity in scales is at the root of the difficulty in quantifying cell function from molecular dynamics and from simulations. The coarse-grained time scale of cellular function is determined from molecular diffusion by the mean first passage time of molecular Brownian motion to a small targets or through narrow passages. The narrow escape theory (NET) concerns this issue. The NET is ubiquitous in molecular and cellular biology and is manifested, among others, in chemical reactions, in the calculation of the effective diffusion coefficient of receptors diffusing on a neuronal cell membrane strewn with obstacles, in the quantification of the early steps of viral trafficking, in the regulation of diffusion between the mother and daughter cells during cell division, and many other cases. Brownian trajectories can represent the motion of a molecule, a protein, an ion in solution, a receptor in a cell or on its membrane, and many other biochemical processes. The small target can represent a binding site or an ionic channel, a hidden active site embedded in a complex protein structure, a receptor for a neurotransmitter on the membrane of a neuron, and so on. The mean time to attach to a receptor or activator determines diffusion fluxes that are key regulators of cell function. This review describes physical models of various subcellular microdomains, in which the NET coarse-grains the molecular scale to a higher cellular-level, thus clarifying the role of cell geometry in determining subcellular function. (topical review)

Time scale of diffusion in molecular and cellular biology

Science.gov (United States)

Holcman, D.; Schuss, Z.

2014-05-01

Diffusion is the driver of critical biological processes in cellular and molecular biology. The diverse temporal scales of cellular function are determined by vastly diverse spatial scales in most biophysical processes. The latter are due, among others, to small binding sites inside or on the cell membrane or to narrow passages between large cellular compartments. The great disparity in scales is at the root of the difficulty in quantifying cell function from molecular dynamics and from simulations. The coarse-grained time scale of cellular function is determined from molecular diffusion by the mean first passage time of molecular Brownian motion to a small targets or through narrow passages. The narrow escape theory (NET) concerns this issue. The NET is ubiquitous in molecular and cellular biology and is manifested, among others, in chemical reactions, in the calculation of the effective diffusion coefficient of receptors diffusing on a neuronal cell membrane strewn with obstacles, in the quantification of the early steps of viral trafficking, in the regulation of diffusion between the mother and daughter cells during cell division, and many other cases. Brownian trajectories can represent the motion of a molecule, a protein, an ion in solution, a receptor in a cell or on its membrane, and many other biochemical processes. The small target can represent a binding site or an ionic channel, a hidden active site embedded in a complex protein structure, a receptor for a neurotransmitter on the membrane of a neuron, and so on. The mean time to attach to a receptor or activator determines diffusion fluxes that are key regulators of cell function. This review describes physical models of various subcellular microdomains, in which the NET coarse-grains the molecular scale to a higher cellular-level, thus clarifying the role of cell geometry in determining subcellular function.

Molecular biology in studies of oceanic primary production

International Nuclear Information System (INIS)

LaRoche, J.; Falkowski, P.G.; Geider, R.

1992-01-01

Remote sensing and the use of moored in situ instrumentation has greatly improved our ability to measure phytoplankton chlorophyll and photosynthesis on global scales with high temporal resolution. However, the interpretation of these measurements and their significance with respect to the biogeochemical cycling of carbon relies on their relationship with physiological and biochemical processes in phytoplankton. For example, the use of satellite images of surface chlorophyll to estimate primary production is often based on the functional relationship between photosynthesis and irradiance. A variety of environmental factors such as light, temperature, nutrient availability affect the photosynthesis/irradiance (P vs I) relationship in phytoplankton. We present three examples showing how molecular biology can be used to provide basic insight into the factors controlling primary productivity at three different levels of complexity: 1. Studies of light intensity regulation in unicellular alga show how molecular biology can help understand the processing of environmental cues leading to the regulation of photosynthetic gene expression. 2. Probing of the photosynthetic apparatus using molecular techniques can be used to test existing mechanistic models derived from the interpretation of physiological and biophysical measurements. 3. Exploratory work on the expression of specific proteins during nutrient-limited growth of phytoplankton may lead to the identification and production of molecular probes for field studies

The early years of molecular biology: personal recollections.

Science.gov (United States)

Holliday, Robin

2003-05-01

The early years of molecular biology were characterized by a strong interaction between theory and experiment. This included the elucidation of the structure of DNA itself; genetic fine structure, recombination and repair; DNA replication; template-directed protein synthesis; the universality of the triplet genetic code, and the co-linearity of the DNA sequence of structural genes and the sequence of amino acids in proteins. The principle of co-linearity was later modified when split genes were discovered. It is suggested that accurate splicing of gene transcripts might also be template directed. In 1958 Crick proposed a 'central dogma' of molecular biology stating that information could not be transmitted from proteins to DNA. Nevertheless, proteins can chemically modify DNA, and this is now known to have strong effects on gene expression.

A comparative cellular and molecular biology of longevity database.

Science.gov (United States)

Stuart, Jeffrey A; Liang, Ping; Luo, Xuemei; Page, Melissa M; Gallagher, Emily J; Christoff, Casey A; Robb, Ellen L

2013-10-01

Discovering key cellular and molecular traits that promote longevity is a major goal of aging and longevity research. One experimental strategy is to determine which traits have been selected during the evolution of longevity in naturally long-lived animal species. This comparative approach has been applied to lifespan research for nearly four decades, yielding hundreds of datasets describing aspects of cell and molecular biology hypothesized to relate to animal longevity. Here, we introduce a Comparative Cellular and Molecular Biology of Longevity Database, available at ( http://genomics.brocku.ca/ccmbl/ ), as a compendium of comparative cell and molecular data presented in the context of longevity. This open access database will facilitate the meta-analysis of amalgamated datasets using standardized maximum lifespan (MLSP) data (from AnAge). The first edition contains over 800 data records describing experimental measurements of cellular stress resistance, reactive oxygen species metabolism, membrane composition, protein homeostasis, and genome homeostasis as they relate to vertebrate species MLSP. The purpose of this review is to introduce the database and briefly demonstrate its use in the meta-analysis of combined datasets.

Cold Spring Harbor symposia on quantitative biology: Volume 51, Molecular biology of /ital Homo sapiens/

International Nuclear Information System (INIS)

1986-01-01

This volume is the second part of a collection of papers submitted by the participants to the 1986 Cold Spring Harbor Symposium on Quantitative Biology entitled Molecular Biology of /ital Homo sapiens/. The 49 papers included in this volume are grouped by subject into receptors, human cancer genes, and gene therapy. (DT)

2012 Gordon Research Conference on Cellular and Molecular Fungal Biology, Final Progress Report

Energy Technology Data Exchange (ETDEWEB)

Berman, Judith [Univ. of Minnesota, Minneapolis, MN (United States)

2012-06-22

The Gordon Research Conference on Cellular and Molecular Fungal Biology was held at Holderness School, Holderness New Hampshire, June 17 - 22, 2012. The 2012 Gordon Conference on Cellular and Molecular Fungal Biology (CMFB) will present the latest, cutting-edge research on the exciting and growing field of molecular and cellular aspects of fungal biology. Topics will range from yeast to filamentous fungi, from model systems to economically important organisms, and from saprophytes and commensals to pathogens of plants and animals. The CMFB conference will feature a wide range of topics including systems biology, cell biology and morphogenesis, organismal interactions, genome organisation and regulation, pathogenesis, energy metabolism, biomass production and population genomics. The Conference was well-attended with 136 participants. Gordon Research Conferences does not permit publication of meeting proceedings.

Reactions driving conformational movements (molecular motors) in gels: conformational and structural chemical kinetics.

Science.gov (United States)

Otero, Toribio F

2017-01-18

In this perspective the empirical kinetics of conducting polymers exchanging anions and solvent during electrochemical reactions to get dense reactive gels is reviewed. The reaction drives conformational movements of the chains (molecular motors), exchange of ions and solvent with the electrolyte and structural (relaxation, swelling, shrinking and compaction) gel changes. Reaction-driven structural changes are identified and quantified from electrochemical responses. The empirical reaction activation energy (E a ), the reaction coefficient (k) and the reaction orders (α and β) change as a function of the conformational energy variation during the reaction. This conformational energy becomes an empirical magnitude. E a , k, α and β include and provide quantitative conformational and structural information. The chemical kinetics becomes structural chemical kinetics (SCK) for reactions driving conformational movements of the reactants. The electrochemically stimulated conformational relaxation model describes empirical results and some results from the literature for biochemical reactions. In parallel the development of an emerging technological world of soft, wet, multifunctional and biomimetic tools and anthropomorphic robots driven by reactions of the constitutive material, as in biological organs, can be now envisaged being theoretically supported by the kinetic model.

Dynamic control of chiral space in a catalytic asymmetric reaction using a molecular motor

NARCIS (Netherlands)

Wang, Jiaobing; Feringa, B.L.

2011-01-01

Enzymes and synthetic chiral catalysts have found widespread application to produce single enantiomers, but in situ switching of the chiral preference of a catalytic system is very difficult to achieve. Here, we report on a light-driven molecular motor with integrated catalytic functions in which

A Theoretical Investigation on Rectifying Performance of a Single Motor Molecular Device

International Nuclear Information System (INIS)

Lei Hui; Tan Xun-Qiong

2015-01-01

We report ab initio calculations of the transport behavior of a phenyl substituted molecular motor. The calculated results show that the transport behavior of the device is sensitive to the rotation degree of the rotor part. When the rotor part is parallel with the stator part, a better rectifying performance can be found in the current-voltage curve. However, when the rotor part revolves to vertical with the stator part, the currents in the positive bias region decrease slightly. More importantly, the rectifying performance disappears. Thus this offers us a new method to modulate the rectifying behavior in molecular devices. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Generative Mechanistic Explanation Building in Undergraduate Molecular and Cellular Biology

Science.gov (United States)

Southard, Katelyn M.; Espindola, Melissa R.; Zaepfel, Samantha D.; Bolger, Molly S.

2017-01-01

When conducting scientific research, experts in molecular and cellular biology (MCB) use specific reasoning strategies to construct mechanistic explanations for the underlying causal features of molecular phenomena. We explored how undergraduate students applied this scientific practice in MCB. Drawing from studies of explanation building among…

Systems theoretic analysis of the central dogma of molecular biology: some recent results.

Science.gov (United States)

Gao, Rui; Yu, Juanyi; Zhang, Mingjun; Tarn, Tzyh-Jong; Li, Jr-Shin

2010-03-01

This paper extends our early study on a mathematical formulation of the central dogma of molecular biology, and focuses discussions on recent insights obtained by employing advanced systems theoretic analysis. The goal of this paper is to mathematically represent and interpret the genetic information flow at the molecular level, and explore the fundamental principle of molecular biology at the system level. Specifically, group theory was employed to interpret concepts and properties of gene mutation, and predict backbone torsion angle along the peptide chain. Finite state machine theory was extensively applied to interpret key concepts and analyze the processes related to DNA hybridization. Using the proposed model, we have transferred the character-based model in molecular biology to a sophisticated mathematical model for calculation and interpretation.

Gregory Bateson's relevance to current molecular biology

DEFF Research Database (Denmark)

Bruni, Luis Emilio

2008-01-01

in a developmental pathway. Being a central figure in the development of cybernetic theory he collaborated with a range of researchers from the life sciences who were innovating their own disciplines by introducing cybernetic concepts in their particular fields and disciplines. In the light of this, it should...... not come as a surprise today to realize how the general ideas that he was postulating for the study of communication systems in biology fit so well with the astonishing findings of current molecular biology, for example in the field of cellular signal transduction networks. I guess this is the case due...

Bacteriophages: The viruses for all seasons of molecular biology

Directory of Open Access Journals (Sweden)

Karam Jim D

2005-03-01

Full Text Available Abstract Bacteriophage research continues to break new ground in our understanding of the basic molecular mechanisms of gene action and biological structure. The abundance of bacteriophages in nature and the diversity of their genomes are two reasons why phage research brims with excitement. The pages of Virology Journal will reflect the excitement of the "New Phage Biology."

Fundamental Approaches in Molecular Biology for Communication Sciences and Disorders

Science.gov (United States)

Bartlett, Rebecca S.; Jette, Marie E.; King, Suzanne N.; Schaser, Allison; Thibeault, Susan L.

2012-01-01

Purpose: This contemporary tutorial will introduce general principles of molecular biology, common deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and protein assays and their relevance in the field of communication sciences and disorders. Method: Over the past 2 decades, knowledge of the molecular pathophysiology of human disease has…

2011 Archaea: Ecology, Metabolism, & Molecular Biology

Energy Technology Data Exchange (ETDEWEB)

Keneth Stedman

2011-08-05

Archaea, one of three major evolutionary lineages of life, are a fascinating and diverse group of microbes with deep roots overlapping those of eukaryotes. The focus of the 'Archaea: Ecology Metabolism & Molecular Biology' GRC conference expands on a number of emerging topics highlighting new paradigms in archaeal metabolism, genome function and systems biology; information processing; evolution and the tree of life; the ecology and diversity of archaea and their viruses. The strength of this conference lies in its ability to couple a field with a rich history in high quality research with new scientific findings in an atmosphere of stimulating exchange. This conference remains an excellent opportunity for younger scientists to interact with world experts in this field.

Cellular and Molecular Biological Approaches to Interpreting Ancient Biomarkers

Science.gov (United States)

Newman, Dianne K.; Neubauer, Cajetan; Ricci, Jessica N.; Wu, Chia-Hung; Pearson, Ann

2016-06-01

Our ability to read the molecular fossil record has advanced significantly in the past decade. Improvements in biomarker sampling and quantification methods, expansion of molecular sequence databases, and the application of genetic and cellular biological tools to problems in biomarker research have enabled much of this progress. By way of example, we review how attempts to understand the biological function of 2-methylhopanoids in modern bacteria have changed our interpretation of what their molecular fossils tell us about the early history of life. They were once thought to be biomarkers of cyanobacteria and hence the evolution of oxygenic photosynthesis, but we now believe that 2-methylhopanoid biosynthetic capacity originated in the Alphaproteobacteria, that 2-methylhopanoids are regulated in response to stress, and that hopanoid 2-methylation enhances membrane rigidity. We present a new interpretation of 2-methylhopanes that bridges the gap between studies of the functions of 2-methylhopanoids and their patterns of occurrence in the rock record.

Quantitative computational models of molecular self-assembly in systems biology.

Science.gov (United States)

Thomas, Marcus; Schwartz, Russell

2017-05-23

Molecular self-assembly is the dominant form of chemical reaction in living systems, yet efforts at systems biology modeling are only beginning to appreciate the need for and challenges to accurate quantitative modeling of self-assembly. Self-assembly reactions are essential to nearly every important process in cell and molecular biology and handling them is thus a necessary step in building comprehensive models of complex cellular systems. They present exceptional challenges, however, to standard methods for simulating complex systems. While the general systems biology world is just beginning to deal with these challenges, there is an extensive literature dealing with them for more specialized self-assembly modeling. This review will examine the challenges of self-assembly modeling, nascent efforts to deal with these challenges in the systems modeling community, and some of the solutions offered in prior work on self-assembly specifically. The review concludes with some consideration of the likely role of self-assembly in the future of complex biological system models more generally.

Molecular interactions and residues involved in force generation in the T4 viral DNA packaging motor.

Science.gov (United States)

Migliori, Amy D; Smith, Douglas E; Arya, Gaurav

2014-12-12

Many viruses utilize molecular motors to package their genomes into preformed capsids. A striking feature of these motors is their ability to generate large forces to drive DNA translocation against entropic, electrostatic, and bending forces resisting DNA confinement. A model based on recently resolved structures of the bacteriophage T4 motor protein gp17 suggests that this motor generates large forces by undergoing a conformational change from an extended to a compact state. This transition is proposed to be driven by electrostatic interactions between complementarily charged residues across the interface between the N- and C-terminal domains of gp17. Here we use atomistic molecular dynamics simulations to investigate in detail the molecular interactions and residues involved in such a compaction transition of gp17. We find that although electrostatic interactions between charged residues contribute significantly to the overall free energy change of compaction, interactions mediated by the uncharged residues are equally if not more important. We identify five charged residues and six uncharged residues at the interface that play a dominant role in the compaction transition and also reveal salt bridging, van der Waals, and solvent hydrogen-bonding interactions mediated by these residues in stabilizing the compact form of gp17. The formation of a salt bridge between Glu309 and Arg494 is found to be particularly crucial, consistent with experiments showing complete abrogation in packaging upon Glu309Lys mutation. The computed contributions of several other residues are also found to correlate well with single-molecule measurements of impairments in DNA translocation activity caused by site-directed mutations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Unconstrained steps of myosin VI appear longest among known molecular motors.

Science.gov (United States)

Ali, M Yusuf; Homma, Kazuaki; Iwane, Atsuko Hikikoshi; Adachi, Kengo; Itoh, Hiroyasu; Kinosita, Kazuhiko; Yanagida, Toshio; Ikebe, Mitsuo

2004-06-01

Myosin VI is a two-headed molecular motor that moves along an actin filament in the direction opposite to most other myosins. Previously, a single myosin VI molecule has been shown to proceed with steps that are large compared to its neck size: either it walks by somehow extending its neck or one head slides along actin for a long distance before the other head lands. To inquire into these and other possible mechanism of motility, we suspended an actin filament between two plastic beads, and let a single myosin VI molecule carrying a bead duplex move along the actin. This configuration, unlike previous studies, allows unconstrained rotation of myosin VI around the right-handed double helix of actin. Myosin VI moved almost straight or as a right-handed spiral with a pitch of several micrometers, indicating that the molecule walks with strides slightly longer than the actin helical repeat of 36 nm. The large steps without much rotation suggest kinesin-type walking with extended and flexible necks, but how to move forward with flexible necks, even under a backward load, is not clear. As an answer, we propose that a conformational change in the lifted head would facilitate landing on a forward, rather than backward, site. This mechanism may underlie stepping of all two-headed molecular motors including kinesin and myosin V.

Molecular radiation biology: Future aspects

International Nuclear Information System (INIS)

Hagen, U.

1990-01-01

Future aspects of molecular radiation biology may be envisaged by looking for unsolved problems and ways to analyse them. Considering the endpoints of cellular radiation effects as cell inactivation, chromosome aberrations, mutation and transformation, the type of DNA damage in the irradiated cell and the mechanisms of DNA repair as excision repair, recombination repair and mutagenic repair are essential topics. At present, great efforts are made to identify, to clone and to sequence genes involved in the control of repair of DNA damage and to study their regulation. There are close relationships between DNA repair genes isolated from various organisms, which promises fast progress for the molecular analysis of repair processes in mammalian cells. More knowledge is necessary regarding the function of the gene products, i.e. enzymes and proteins involved in DNA repair. Effort should be made to analyse the enzymatic reactions, leading to an altered nucleotide sequence, encountered as a point mutation. Mislead mismatch repair and modulation of DNA polymerase might be possible mechanisms. (orig.)

Molecular biology of gastric cancer.

Science.gov (United States)

Cervantes, A; Rodríguez Braun, E; Pérez Fidalgo, A; Chirivella González, I

2007-04-01

Despite its decreasing incidence overall, gastric cancer is still a challenging disease. Therapy is based mainly upon surgical resection when the tumour remains localised in the stomach. Conventional chemotherapy may play a role in treating micrometastatic disease and is effective as palliative therapy for recurrent or advanced disease. However, the knowledge of molecular pathways implicated in gastric cancer pathogenesis is still in its infancy and the contribution of molecular biology to the development of new targeted therapies in gastric cancer is far behind other more common cancers such as breast, colon or lung. This review will focus first on the difference of two well defined types of gastric cancer: intestinal and diffuse. A discussion of the cell of origin of gastric cancer with some intriguing data implicating bone marrow derived cells will follow, and a comprehensive review of different genetic alterations detected in gastric cancer, underlining those that may have clinical, therapeutic or prognostic implications.

A comprehensive study into the molecular methodology and molecular biology of methanogenic Archaea

DEFF Research Database (Denmark)

Lange, M.; Ahring, Birgitte Kiær

2001-01-01

Methanogens belong to the kingdom of Euryarchaeota in the domain of Archaea. The Archaea differ from Bacteria in many aspects important to molecular work. Among these are cell wall composition, their sensitivity to antibiotics, their translation and transcription machinery, and their very strict ...... procedures. Efficient genetic manipulation systems, including shuttle and integration vector systems, have appeared for mesophilic, but not for thermophilic species within the last few years and will have a major impact on future investigations of methanogenic molecular biology....

Life without double-headed non-muscle myosin II motor proteins

Science.gov (United States)

Betapudi, Venkaiah

2014-07-01

Non-muscle myosin II motor proteins (myosin IIA, myosin IIB, and myosin IIC) belong to a class of molecular motor proteins that are known to transduce cellular free-energy into biological work more efficiently than man-made combustion engines. Nature has given a single myosin II motor protein for lower eukaryotes and multiple for mammals but none for plants in order to provide impetus for their life. These specialized nanomachines drive cellular activities necessary for embryogenesis, organogenesis, and immunity. However, these multifunctional myosin II motor proteins are believed to go awry due to unknown reasons and contribute for the onset and progression of many autosomal-dominant disorders, cataract, deafness, infertility, cancer, kidney, neuronal, and inflammatory diseases. Many pathogens like HIV, Dengue, hepatitis C, and Lymphoma viruses as well as Salmonella and Mycobacteria are now known to take hostage of these dedicated myosin II motor proteins for their efficient pathogenesis. Even after four decades since their discovery, we still have a limited knowledge of how these motor proteins drive cell migration and cytokinesis. We need to enrich our current knowledge on these fundamental cellular processes and develop novel therapeutic strategies to fix mutated myosin II motor proteins in pathological conditions. This is the time to think how to relieve the hijacked myosins from pathogens in order to provide a renewed impetus for patients’ life. Understanding how to steer these molecular motors in proliferating and differentiating stem cells will improve stem cell based-therapeutics development. Given the plethora of cellular activities non-muscle myosin motor proteins are involved in, their importance is apparent for human life.

Life without double-headed non-muscle myosin II motor proteins

Directory of Open Access Journals (Sweden)

Venkaiah eBetapudi

2014-07-01

Full Text Available Non-muscle myosin II motor proteins (myosin IIA, myosin IIB, and myosin IIC belong to a class of molecular motor proteins that are known to transduce cellular free-energy into biological work more efficiently than man-made combustion engines. Nature has given a single myosin II motor protein for lower eukaryotes and multiple for mammals but none for plants in order to provide impetus for their life. These specialized nanomachines drive cellular activities necessary for embryogenesis, organogenesis, and immunity. However, these multifunctional myosin II motor proteins are believed to go awry due to unknown reasons and contribute for the onset and progression of many autosomal-dominant disorders, cataract, deafness, infertility, cancer, kidney, neuronal, and inflammatory diseases. Many pathogens like HIV, Dengue, hepatitis C, and Lymphoma viruses as well as Salmonella and Mycobacteria are now known to take hostage of these dedicated myosin II motor proteins for their efficient pathogenesis. Even after four decades since their discovery, we still have a limited knowledge of how these motor proteins drive cell migration and cytokinesis. We need to enrich our current knowledge on these fundamental cellular processes and develop novel therapeutic strategies to fix mutated myosin II motor proteins in pathological conditions. This is the time to think how to relieve the hijacked myosins from pathogens in order to provide a renewed impetus for patients’ life. Understanding how to steer these molecular motors in proliferating and differentiating stem cells will improve stem cell based-therapeutics development. Given the plethora of cellular activities non-muscle myosin motor proteins are involved in, their importance is apparent for human life.

Generative mechanistic explanation building in undergraduate molecular and cellular biology

Science.gov (United States)

Southard, Katelyn M.; Espindola, Melissa R.; Zaepfel, Samantha D.; Bolger, Molly S.

2017-09-01

When conducting scientific research, experts in molecular and cellular biology (MCB) use specific reasoning strategies to construct mechanistic explanations for the underlying causal features of molecular phenomena. We explored how undergraduate students applied this scientific practice in MCB. Drawing from studies of explanation building among scientists, we created and applied a theoretical framework to explore the strategies students use to construct explanations for 'novel' biological phenomena. Specifically, we explored how students navigated the multi-level nature of complex biological systems using generative mechanistic reasoning. Interviews were conducted with introductory and upper-division biology students at a large public university in the United States. Results of qualitative coding revealed key features of students' explanation building. Students used modular thinking to consider the functional subdivisions of the system, which they 'filled in' to varying degrees with mechanistic elements. They also hypothesised the involvement of mechanistic entities and instantiated abstract schema to adapt their explanations to unfamiliar biological contexts. Finally, we explored the flexible thinking that students used to hypothesise the impact of mutations on multi-leveled biological systems. Results revealed a number of ways that students drew mechanistic connections between molecules, functional modules (sets of molecules with an emergent function), cells, tissues, organisms and populations.

Practices and exploration on competition of molecular biological detection technology among students in food quality and safety major.

Science.gov (United States)

Chang, Yaning; Peng, Yuke; Li, Pengfei; Zhuang, Yingping

2017-07-08

With the increasing importance in the application of the molecular biological detection technology in the field of food safety, strengthening education in molecular biology experimental techniques is more necessary for the culture of the students in food quality and safety major. However, molecular biology experiments are not always in curricula of Food quality and safety Majors. This paper introduced a project "competition of molecular biological detection technology for food safety among undergraduate sophomore students in food quality and safety major", students participating in this project needed to learn the fundamental molecular biology experimental techniques such as the principles of molecular biology experiments and genome extraction, PCR and agarose gel electrophoresis analysis, and then design the experiments in groups to identify the meat species in pork and beef products using molecular biological methods. The students should complete the experimental report after basic experiments, write essays and make a presentation after the end of the designed experiments. This project aims to provide another way for food quality and safety majors to improve their knowledge of molecular biology, especially experimental technology, and enhances them to understand the scientific research activities as well as give them a chance to learn how to write a professional thesis. In addition, in line with the principle of an open laboratory, the project is also open to students in other majors in East China University of Science and Technology, in order to enhance students in other majors to understand the fields of molecular biology and food safety. © 2017 by The International Union of Biochemistry and Molecular Biology, 45(4):343-350, 2017. © 2017 The International Union of Biochemistry and Molecular Biology.

A national comparison of biochemistry and molecular biology capstone experiences.

Science.gov (United States)

Aguanno, Ann; Mertz, Pamela; Martin, Debra; Bell, Ellis

2015-01-01

Recognizing the increasingly integrative nature of the molecular life sciences, the American Society for Biochemistry and Molecular Biology (ASBMB) recommends that Biochemistry and Molecular Biology (BMB) programs develop curricula based on concepts, content, topics, and expected student outcomes, rather than courses. To that end, ASBMB conducted a series of regional workshops to build a BMB Concept Inventory containing validated assessment tools, based on foundational and discipline-specific knowledge and essential skills, for the community to use. A culminating activity, which integrates the educational experience, is often part of undergraduate molecular life science programs. These "capstone" experiences are commonly defined as an attempt to measure student ability to synthesize and integrate acquired knowledge. However, the format, implementation, and approach to outcome assessment of these experiences are quite varied across the nation. Here we report the results of a nation-wide survey on BMB capstone experiences and discuss this in the context of published reports about capstones and the findings of the workshops driving the development of the BMB Concept Inventory. Both the survey results and the published reports reveal that, although capstone practices do vary, certain formats for the experience are used more frequently and similarities in learning objectives were identified. The use of rubrics to measure student learning is also regularly reported, but details about these assessment instruments are sparse in the literature and were not a focus of our survey. Finally, we outline commonalities in the current practice of capstones and suggest the next steps needed to elucidate best practices. © 2015 The International Union of Biochemistry and Molecular Biology.

Using a Computer Animation to Teach High School Molecular Biology

Science.gov (United States)

Rotbain, Yosi; Marbach-Ad, Gili; Stavy, Ruth

2008-01-01

We present an active way to use a computer animation in secondary molecular genetics class. For this purpose we developed an activity booklet that helps students to work interactively with a computer animation which deals with abstract concepts and processes in molecular biology. The achievements of the experimental group were compared with those…

Theoretical molecular biophysics

CERN Document Server

Scherer, Philipp O J

2017-01-01

This book gives an introduction to molecular biophysics. It starts from material properties at equilibrium related to polymers, dielectrics and membranes. Electronic spectra are developed for the understanding of elementary dynamic processes in photosynthesis including proton transfer and dynamics of molecular motors. Since the molecular structures of functional groups of bio-systems were resolved, it has become feasible to develop a theory based on the quantum theory and statistical physics with emphasis on the specifics of the high complexity of bio-systems. This introduction to molecular aspects of the field focuses on solvable models. Elementary biological processes provide as special challenge the presence of partial disorder in the structure which does not destroy the basic reproducibility of the processes. Apparently the elementary molecular processes are organized in a way to optimize the efficiency. Learning from nature by means exploring the relation between structure and function may even help to b...

Editorial: Molecular Organization of Membranes: Where Biology Meets Biophysics

Czech Academy of Sciences Publication Activity Database

Cebecauer, Marek; Holowka, D.

2017-01-01

Roč. 5, č. 113 (2017), s. 1-3 ISSN 2296-634X Institutional support: RVO:61388955 Keywords : nanodomains * membrane properties * cell membrane Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology

Molecular imaging of prostate cancer: translating molecular biology approaches into the clinical realm.

Science.gov (United States)

Vargas, Hebert Alberto; Grimm, Jan; F Donati, Olivio; Sala, Evis; Hricak, Hedvig

2015-05-01

The epidemiology of prostate cancer has dramatically changed since the introduction of prostate-specific antigen (PSA) screening in the 1980's. Most prostate cancers today are detected at early stages of the disease and are considered 'indolent'; however, some patients' prostate cancers demonstrate a more aggressive behaviour which leads to rapid progression and death. Increasing understanding of the biology underlying the heterogeneity that characterises this disease has led to a continuously evolving role of imaging in the management of prostate cancer. Functional and metabolic imaging techniques are gaining importance as the impact on the therapeutic paradigm has shifted from structural tumour detection alone to distinguishing patients with indolent tumours that can be managed conservatively (e.g., by active surveillance) from patients with more aggressive tumours that may require definitive treatment with surgery or radiation. In this review, we discuss advanced imaging techniques that allow direct visualisation of molecular interactions relevant to prostate cancer and their potential for translation to the clinical setting in the near future. The potential use of imaging to follow molecular events during drug therapy as well as the use of imaging agents for therapeutic purposes will also be discussed. • Advanced imaging techniques allow direct visualisation of molecular interactions in prostate cancer. • MRI/PET, optical and Cerenkov imaging facilitate the translation of molecular biology. • Multiple compounds targeting PSMA expression are currently undergoing clinical translation. • Other targets (e.g., PSA, prostate-stem cell antigen, GRPR) are in development.

Proceedings of the symposium on molecular biology and radiation protection

International Nuclear Information System (INIS)

Marko, A.M.

1996-02-01

The symposium on molecular biology and radiation protection was organized in sessions with the following titles: Radiation protection and the human genome; Molecular changes in DNA induced by radiation; Incidence of genetic changes - pre-existing, spontaneous and radiation-induced; Research directions and ethical implications. The ten papers in the symposium have been abstracted individually

Proceedings of the symposium on molecular biology and radiation protection

Energy Technology Data Exchange (ETDEWEB)

Marko, A M [Atomic Energy Control Board, Ottawa, ON (Canada). Advisory Committee on Radiological Protection; Myers, D K; Atchison, R J [Atomic Energy Control Board, Ottawa, ON (Canada). Advisory Committee on Radiological Protection. Secretariat; Gentner, N E [Atomic Energy of Canada Ltd., Chalk River, ON (Canada)

1996-02-01

The symposium on molecular biology and radiation protection was organized in sessions with the following titles: Radiation protection and the human genome; Molecular changes in DNA induced by radiation; Incidence of genetic changes - pre-existing, spontaneous and radiation-induced; Research directions and ethical implications. The ten papers in the symposium have been abstracted individually.

[Molecular Biology for Surgical Treatment of Lung Cancer].

Science.gov (United States)

Suda, Kenichi; Mitsudomi, Tetsuya

2017-01-01

Progress in lung cancer research achieved during the last 10 years was summarized. These include identification of novel driver mutations and application of targeted therapies, resistance mechanisms to targeted therapies, and immunotherapy with immune checkpoint inhibitors. Molecular biology also affects the field of surgical treatment. Several molecular markers have been reported to predict benign/ malignant or stable/growing tumors, although far from clinical application. In perioperative period, there is a possibility of atrial natriuretic peptide to prevent cancer metastasis. As adjuvant settings, although biomarker-based cytotoxic therapies failed to show clinical efficacy, several trials are ongoing employing molecular targeted agents (EGFR-TKI or ALK-TKI) or immune checkpoint inhibitors. In clinical practice, mutational information is sometimes used to distinguish 2nd primary tumors from pulmonary metastases of previous cancers. Surgery also has important role for oligo-progressive disease during molecular targeted therapies.

Molecular biology of mycoplasmas: from the minimum cell concept to the artificial cell.

Science.gov (United States)

Cordova, Caio M M; Hoeltgebaum, Daniela L; Machado, Laís D P N; Santos, Larissa Dos

2016-01-01

Mycoplasmas are a large group of bacteria, sorted into different genera in the Mollicutes class, whose main characteristic in common, besides the small genome, is the absence of cell wall. They are considered cellular and molecular biology study models. We present an updated review of the molecular biology of these model microorganisms and the development of replicative vectors for the transformation of mycoplasmas. Synthetic biology studies inspired by these pioneering works became possible and won the attention of the mainstream media. For the first time, an artificial genome was synthesized (a minimal genome produced from consensus sequences obtained from mycoplasmas). For the first time, a functional artificial cell has been constructed by introducing a genome completely synthesized within a cell envelope of a mycoplasma obtained by transformation techniques. Therefore, this article offers an updated insight to the state of the art of these peculiar organisms' molecular biology.

Sailing to and Docking at the Immune Synapse: Role of Tubulin Dynamics and Molecular Motors

Directory of Open Access Journals (Sweden)

Noa Beatriz Martín-Cófreces

2018-05-01

Full Text Available The different cytoskeleton systems and their connecting molecular motors move vesicles and intracellular organelles to shape cells. Polarized cells with specialized functions display an exquisite spatio-temporal regulation of both cytoskeletal and organelle arrangements that support their specific tasks. In particular, T cells rapidly change their shape and cellular function through the establishment of cell surface and intracellular polarity in response to a variety of cues. This review focuses on the contribution of the microtubule-based dynein/dynactin motor complex, the tubulin and actin cytoskeletons, and different organelles to the formation of the antigen-driven immune synapse.

Molecular biology applications to infectious diseases diagnostic; Aplicaciones de la Biologica Molecular al diagnostico de enfermedades infecciosas

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

This project goes directed to the applications of the techniques of molecular biology in hepatitis virus.A great advance of these techniques it allows its application to the diagnose molecular and it becomes indispensable to have these fundamental tools in the field of the Health Public for the detection precocious, pursuit of the treatment, the one predicts and the evolution of the patient hepatitis bearing virus technical.Use of molecular biology to increase the handling and the control of the patients with hepatitis B and C and to detect an adult numbers of positive cases by means of the training and integration of all the countries participating.Implement the technique of PCR to identify the virus of the hepatitis B and C,implement quantification methods and genotipification for these virus.

Delivery of Biologics Across the Blood-Brain Barrier with Molecular Trojan Horse Technology.

Science.gov (United States)

Pardridge, William M

2017-12-01

Biologics are potential new therapeutics for many diseases of the central nervous system. Biologics include recombinant lysosomal enzymes, neurotrophins, decoy receptors, and therapeutic antibodies. These are large molecule drugs that do not cross the blood-brain barrier (BBB). All classes of biologics have been tested, without success, in clinical trials of brain disease over the last 25 years. In none of these past clinical trials was the biologic re-engineered to enable transport across the BBB. If the biologic does not cross the BBB, the drug cannot reach the target site in brain, and success in a clinical trial is not expected. Biologics can be re-engineered for BBB transport with the use of molecular Trojan horse technology. A BBB molecular Trojan horse is a monoclonal antibody (MAb) against an endogenous BBB receptor transporter, such as the insulin receptor or transferrin receptor. The receptor-specific MAb penetrates the brain via transport on the endogenous BBB receptor. The MAb acts as a molecular Trojan horse to deliver across the BBB the biologic pharmaceutical that is genetically fused to the MAb. The lead Trojan horse is a MAb against the human insulin receptor (HIR), and HIRMAb-derived fusion proteins have entered clinical trials for the treatment of brain disease.

International Conference on Intelligent Systems for Molecular Biology (ISMB)

Energy Technology Data Exchange (ETDEWEB)

Goldberg, Debra; Hibbs, Matthew; Kall, Lukas; Komandurglayavilli, Ravikumar; Mahony, Shaun; Marinescu, Voichita; Mayrose, Itay; Minin, Vladimir; Neeman, Yossef; Nimrod, Guy; Novotny, Marian; Opiyo, Stephen; Portugaly, Elon; Sadka, Tali; Sakabe, Noboru; Sarkar, Indra; Schaub, Marc; Shafer, Paul; Shmygelska, Olena; Singer, Gregory; Song, Yun; Soumyaroop, Bhattacharya; Stadler, Michael; Strope, Pooja; Su, Rong; Tabach, Yuval; Tae, Hongseok; Taylor, Todd; Terribilini, Michael; Thomas, Asha; Tran, Nam; Tseng, Tsai-Tien; Vashist, Akshay; Vijaya, Parthiban; Wang, Kai; Wang, Ting; Wei, Lai; Woo, Yong; Wu, Chunlei; Yamanishi, Yoshihiro; Yan, Changhui; Yang, Jack; Yang, Mary; Ye, Ping; Zhang, Miao

2009-12-29

The Intelligent Systems for Molecular Biology (ISMB) conference has provided a general forum for disseminating the latest developments in bioinformatics on an annual basis for the past 13 years. ISMB is a multidisciplinary conference that brings together scientists from computer science, molecular biology, mathematics and statistics. The goal of the ISMB meeting is to bring together biologists and computational scientists in a focus on actual biological problems, i.e., not simply theoretical calculations. The combined focus on "intelligent systems" and actual biological data makes ISMB a unique and highly important meeting, and 13 years of experience in holding the conference has resulted in a consistently well organized, well attended, and highly respected annual conference. The ISMB 2005 meeting was held June 25-29, 2005 at the Renaissance Center in Detroit, Michigan. The meeting attracted over 1,730 attendees. The science presented was exceptional, and in the course of the five-day meeting, 56 scientific papers, 710 posters, 47 Oral Abstracts, 76 Software demonstrations, and 14 tutorials were presented. The attendees represented a broad spectrum of backgrounds with 7% from commercial companies, over 28% qualifying for student registration, and 41 countries were represented at the conference, emphasizing its important international aspect. The ISMB conference is especially important because the cultures of computer science and biology are so disparate. ISMB, as a full-scale technical conference with refereed proceedings that have been indexed by both MEDLINE and Current Contents since 1996, bridges this cultural gap.

Just Working with the Cellular Machine: A High School Game for Teaching Molecular Biology

Science.gov (United States)

Cardoso, Fernanda Serpa; Dumpel, Renata; Gomes da Silva, Luisa B.; Rodrigues, Carlos R.; Santos, Dilvani O.; Cabral, Lucio Mendes; Castro, Helena C.

2008-01-01

Molecular biology is a difficult comprehension subject due to its high complexity, thus requiring new teaching approaches. Herein, we developed an interdisciplinary board game involving the human immune system response against a bacterial infection for teaching molecular biology at high school. Initially, we created a database with several…

Synthesis, biological evaluation and molecular docking studies of ...

African Journals Online (AJOL)

Synthesis, biological evaluation and molecular docking studies of Mannich bases derived from 1, 3, 4-oxadiazole- 2-thiones as potential urease inhibitors. ... Mannich bases (5-17) were subjected to in silico screening as urease inhibitors, using crystal structure of urease (Protein Data Bank ID: 5FSE) as a model enzyme.

Importancia de la biología molecular para la Fisioterapia moderna Importance of molecular biology for the modern Physical Therapy

Directory of Open Access Journals (Sweden)

Carolina Ramírez Ramírez

2011-12-01

Full Text Available Para que el cuerpo de conocimiento de una profesión crezca y se fortalezca debe estar al día con los avances científicos y tecnológicos que surgen continuamente para incluirlos en el repertorio de recursos que usa para la investigación de problemas específicos de su saber. Recientemente el desciframiento del código genético y la secuenciación del genoma humano creó la base para el surgimiento de metodologías y técnicas en el área de la biología molecular, las cuales permitieron profundizar en el conocimiento de la estructura y función de los tejidos humanos y también mejoraron el entendimiento de los mecanismos por los cuales actúan formas de intervención usadas cotidianamente por profesionales en salud. La Fisioterapia utiliza modalidades físicas que interactúan con los tejidos corporales, por ello la biología molecular permite un mejor entendimiento de los efectos que las dichas modalidades generan en el tejido sobre el cual son aplicadas. Por tanto el objetivo de este artículo es reflexionar sobre la necesidad de que el Fisioterapeuta se apropie del conocimiento en ésta área de las ciencias básicas, usarlo como herramienta para la solución de preguntas relevantes de su quehacer clínico y así contribuir de manera efectiva con la generación de nuevo conocimiento que promueva la práctica basada en la evidencia y fomente el crecimiento de la profesión. Salud UIS 2011; 43 (3: 317-320A profession can be improved through the development and application of scientific and technological advances around the issues relating to their expertise. Recently, the deciphering of the genetic code and human genome sequencing creates the basis for the development of methodologies and techniques of molecular biology. These resources have allowed a deeper understanding of the human tissue structure and function, and intervention mechanisms used by health professionals. Physiotherapy uses physical modalities affecting the tissues of the

A discussion of molecular biology methods for protein engineering

CSIR Research Space (South Africa)

Zawaira, A

2011-09-01

Full Text Available A number of molecular biology techniques are available to generate variants from a particular start gene for eventual protein expression. The authors discuss the basic principles of these methods in a repertoire that may be used to achieve...

Biological Applications of Hybrid Quantum Mechanics/Molecular Mechanics Calculation

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Jiyoung Kang

2012-01-01

Full Text Available Since in most cases biological macromolecular systems including solvent water molecules are remarkably large, the computational costs of performing ab initio calculations for the entire structures are prohibitive. Accordingly, QM calculations that are jointed with MM calculations are crucial to evaluate the long-range electrostatic interactions, which significantly affect the electronic structures of biological macromolecules. A UNIX-shell-based interface program connecting the quantum mechanics (QMs and molecular mechanics (MMs calculation engines, GAMESS and AMBER, was developed in our lab. The system was applied to a metalloenzyme, azurin, and PU.1-DNA complex; thereby, the significance of the environmental effects on the electronic structures of the site of interest was elucidated. Subsequently, hybrid QM/MM molecular dynamics (MD simulation using the calculation system was employed for investigation of mechanisms of hydrolysis (editing reaction in leucyl-tRNA synthetase complexed with the misaminoacylated tRNALeu, and a novel mechanism of the enzymatic reaction was revealed. Thus, our interface program can play a critical role as a powerful tool for state-of-the-art sophisticated hybrid ab initio QM/MM MD simulations of large systems, such as biological macromolecules.

Biodiversity: molecular biological domains, symbiosis and kingdom origins

Science.gov (United States)

Margulis, L.

1992-01-01

The number of extant species of organisms is estimated to be from fewer than 3 to more than 30 x 10(6) (May, 1992). Molecular biology, comparative genetics and ultrastructural analyses provide new insights into evolutionary relationships between these species, including increasingly precise ideas of how species and higher taxa have evolved from common ancestors. Accumulation of random mutations and large macromolecular sequence change in all organisms since the Proterozoic Eon has been importantly supplemented by acquisition of inherited genomes ('symbiogenesis'). Karyotypic alterations (polyploidization and karyotypic fissioning) have been added to these other mechanisms of species origin in plants and animals during the Phanerozoic Eon. The new evolution concepts (coupled with current rapid rates of species extinction and ignorance of the extent of biodiversity) prompted this analysis of the field of systematic biology and its role in the reorganization of extant species into higher taxa. Two superkingdoms (= Domains: Prokaryotae and Eukaryotae) and five kingdoms (Monera = Procaryotae or Bacteria; Protoctista: algae, amoebae, ciliates, foraminifera, oomycetes, slime molds, etc.; Mychota: 'true' fungi; Plantae: one phylum (division) of bryophytes and nine phyla of tracheophytes; and Animalia) are recognized. Two subkingdoms comprise the monera: the great diverse lineages are Archaebacteria and Eubacteria. The criteria for classification using molecular, ultrastructural and genetic data for this scheme are mentioned. For the first time since the nineteenth century, logical, technical definitions for each group are given with their time of appearance as inferred from the fossil record in the primary scientific literature. This classification scheme, which most closely reflects the evolutionary history, molecular biology, genetics and ultrastructure of extant life, requires changes in social organization of biologists, many of whom as botanists and zoologists, still

2009 Archaea: Ecology, Metabolism & Molecular Biology GRC

Energy Technology Data Exchange (ETDEWEB)

Furlow, Julie Maupin- [Univ. of Florida, Gainesville, FL (United States)

2009-07-26

Archaea, one of three major evolutionary lineages of life, are a fascinating and diverse group of microbes with deep roots overlapping those of eukaryotes. The focus of the 'Archaea: Ecology Metabolism & Molecular Biology' GRC conference expands on a number of emerging topics highlighting new paradigms in archaeal metabolism, genome function and systems biology; information processing; evolution and the tree of life; the ecology and diversity of archaea and their viruses; and industrial applications. The strength of this conference lies in its ability to couple a field with a rich history in high quality research with new scientific findings in an atmosphere of stimulating exchange. This conference remains an excellent opportunity for younger scientists to interact with world experts in this field.

Nutritional education from Molecular and Cellular Biology

Directory of Open Access Journals (Sweden)

Zaida Ramona Betancourt Betancourt

2014-12-01

Full Text Available The nutritional education is current topic, constituting a necessity in the contemporary world, given mainly by the contribution that it makes in maintaining the human health under good conditions. Starting from this problem, it is presented this article whose objective is: to show the potential ities that the discipline Cellular and Molecular Biology offers, for the treatment of these contents, since this discipline is worked in the second semester of first year and first semester of in the formation of professors of the Biology - Geography and Bio logy - C hemistry careers which can contribute to the development of knowledge, habits and abilities that allows them to appropriate of responsible behaviours for the achievement of correct nutritional habits.

Organization of a radioisotope based molecular biology laboratory

International Nuclear Information System (INIS)

2006-12-01

Polymerase chain reaction (PCR) has revolutionized the application of molecular techniques to medicine. Together with other molecular biology techniques it is being increasingly applied to human health for identifying prognostic markers and drug resistant profiles, developing diagnostic tests and genotyping systems and for treatment follow-up of certain diseases in developed countries. Developing Member States have expressed their need to also benefit from the dissemination of molecular advances. The use of radioisotopes, as a step in the detection process or for increased sensitivity and specificity is well established, making it ideally suitable for technology transfer. Many molecular based projects using isotopes for detecting and studying micro organisms, hereditary and neoplastic diseases are received for approval every year. In keeping with the IAEA's programme, several training activities and seminars have been organized to enhance the capabilities of developing Member States to employ in vitro nuclear medicine technologies for managing their important health problems and for undertaking related basic and clinical research. The background material for this publication was collected at training activities and from feedback received from participants at research and coordination meetings. In addition, a consultants' meeting was held in June 2004 to compile the first draft of this report. Previous IAEA TECDOCS, namely IAEA-TECDOC-748 and IAEA-TECDOC-1001, focused on molecular techniques and their application to medicine while the present publication provides information on organization of the laboratory, quality assurance and radio-safety. The technology has specific requirements of the way the laboratory is organized (e.g. for avoiding contamination and false positives in PCR) and of quality assurance in order to provide accurate information to decision makers. In addition while users of the technology accept the scientific rationale of using radio

Tangible Models and Haptic Representations Aid Learning of Molecular Biology Concepts

Science.gov (United States)

Johannes, Kristen; Powers, Jacklyn; Couper, Lisa; Silberglitt, Matt; Davenport, Jodi

2016-01-01

Can novel 3D models help students develop a deeper understanding of core concepts in molecular biology? We adapted 3D molecular models, developed by scientists, for use in high school science classrooms. The models accurately represent the structural and functional properties of complex DNA and Virus molecules, and provide visual and haptic…

Practices and Exploration on Competition of Molecular Biological Detection Technology among Students in Food Quality and Safety Major

Science.gov (United States)

Chang, Yaning; Peng, Yuke; Li, Pengfei; Zhuang, Yingping

2017-01-01

With the increasing importance in the application of the molecular biological detection technology in the field of food safety, strengthening education in molecular biology experimental techniques is more necessary for the culture of the students in food quality and safety major. However, molecular biology experiments are not always in curricula…

Molecular biology and its applications in orthodontics and oral and maxillofacial surgery

NARCIS (Netherlands)

Ren, Yjin

2005-01-01

: Molecular biology is an exciting, rapidly expanding field, which has enabled enormously greater understanding of the biology of diseases and malfunctions in many fields. It chiefly concerns itself with understanding the interactions between the various systems of a cell, including the

Essential concepts and underlying theories from physics, chemistry, and mathematics for "biochemistry and molecular biology" majors.

Science.gov (United States)

Wright, Ann; Provost, Joseph; Roecklein-Canfield, Jennifer A; Bell, Ellis

2013-01-01

Over the past two years, through an NSF RCN UBE grant, the ASBMB has held regional workshops for faculty members from around the country. The workshops have focused on developing lists of Core Principles or Foundational Concepts in Biochemistry and Molecular Biology, a list of foundational skills, and foundational concepts from Physics, Chemistry, and Mathematics that all Biochemistry or Molecular Biology majors must understand to complete their major coursework. The allied fields working group created a survey to validate foundational concepts from Physics, Chemistry, and Mathematics identified from participant feedback at various workshops. One-hundred twenty participants responded to the survey and 68% of the respondents answered yes to the question: "We have identified the following as the core concepts and underlying theories from Physics, Chemistry, and Mathematics that Biochemistry majors or Molecular Biology majors need to understand after they complete their major courses: 1) mechanical concepts from Physics, 2) energy and thermodynamic concepts from Physics, 3) critical concepts of structure from chemistry, 4) critical concepts of reactions from Chemistry, and 5) essential Mathematics. In your opinion, is the above list complete?" Respondents also delineated subcategories they felt should be included in these broad categories. From the results of the survey and this analysis the allied fields working group constructed a consensus list of allied fields concepts, which will help inform Biochemistry and Molecular Biology educators when considering the ASBMB recommended curriculum for Biochemistry or Molecular Biology majors and in the development of appropriate assessment tools to gauge student understanding of how these concepts relate to biochemistry and molecular biology. © 2013 by The International Union of Biochemistry and Molecular Biology.

The emerging molecular biology toolbox for the study of long noncoding RNA biology.

Science.gov (United States)

Fok, Ezio T; Scholefield, Janine; Fanucchi, Stephanie; Mhlanga, Musa M

2017-10-01

Long noncoding RNAs (lncRNAs) have been implicated in many biological processes. However, due to the unique nature of lncRNAs and the consequential difficulties associated with their characterization, there is a growing disparity between the rate at which lncRNAs are being discovered and the assignment of biological function to these transcripts. Here we present a molecular biology toolbox equipped to help dissect aspects of lncRNA biology and reveal functionality. We outline an approach that begins with a broad survey of genome-wide, high-throughput datasets to identify potential lncRNA candidates and then narrow the focus on specific methods that are well suited to interrogate the transcripts of interest more closely. This involves the use of imaging-based strategies to validate these candidates and observe the behaviors of these transcripts at single molecule resolution in individual cells. We also describe the use of gene editing tools and interactome capture techniques to interrogate functionality and infer mechanism, respectively. With the emergence of lncRNAs as important molecules in healthy and diseased cellular function, it remains crucial to deepen our understanding of their biology.

Molecular biology III - Oncogenes and tumor suppressor genes

International Nuclear Information System (INIS)

Giaccia, Amato J.

1996-01-01

Purpose: The purpose of this course is to introduce to radiation oncologists the basic concepts of tumorigenesis, building on the information that will be presented in the first and second part of this series of lectures. Objective: Our objective is to increase the current understanding of radiation oncologists with the process of tumorigenesis, especially focusing on genes that are altered in many tumor types that are potential candidates for novel molecular strategies. As strategies to treat cancer of cancer are becoming more sophisticated, it will be important for both the practitioner and academician to develop a basic understanding of the function of cancer 'genes'. This will be the third in a series of refresher courses that are meant to address recent advances in Cancer Biology in a way that both clinicians without previous knowledge of molecular biology or experienced researchers will find interesting. The lecture will begin with a basic overview of tumorigenesis; methods of detecting chromosome/DNA alterations, approaches used to isolate oncogenes and tumor suppressor genes, and their role in cell killing by apoptosis. Special attention will be given to oncogenes and tumor suppressor genes that are modulated by ionizing radiation and the tumor microenvironment. We will relate the biology of oncogenes and tumor suppressor genes to basic aspects of radiation biology that would be important in clinical practice. Finally, we will review recent studies on the prognostic significance of p53 mutations and apoptosis in tumor specimens. The main point of this lecture is to relate both researcher and clinician what are the therapeutic ramifications of oncogene and tumor suppressor gene mutations found in human neoptasia

Mechanism of Inhibition of the V-Type Molecular Motor by Tributyltin Chloride

Science.gov (United States)

Takeda, Mizuho; Suno-Ikeda, Chiyo; Shimabukuro, Katsuya; Yoshida, Masasuke; Yokoyama, Ken

2009-01-01

Tributyltin chloride (TBT-Cl) is an endocrine disruptor found in many animal species, and it is also known to be an inhibitor for the V-ATPases that are emerging as potential targets in the treatment of diseases such as osteoporosis and cancer. We demonstrated by using biochemical and single-molecular imaging techniques that TBT-Cl arrests an elementary step for rotary catalysis of the V1 motor domain. In the presence of TBT-Cl, the consecutive rotation of V1 paused for a long duration (∼0.5 s), even at saturated ATP concentrations, and the pausing positions were localized at 120° intervals. Analysis of both the pausing time and moving time revealed that TBT-Cl has little effect on the binding affinity for ATP, but, rather, it arrests the catalytic event(s). This is the first report to demonstrate that an inhibitor arrests an elementary step for rotary catalysis of a V-type ATP-driven rotary motor. PMID:19186155

Egyptian Journal of Biochemistry and Molecular Biology - Vol 32, No ...

African Journals Online (AJOL)

The Egyptian Journal of Biochemistry and Molecular Biology. ... Therapeutic Impacts of Almond Oil and Olive Oil on Cholesterol Dynamics and ... Multidrug Resistance Proteins in Pancreatic Carcinoma · EMAIL FULL TEXT EMAIL FULL TEXT

Script, code, information: how to differentiate analogies in the "prehistory" of molecular biology.

Science.gov (United States)

Kogge, Werner

2012-01-01

The remarkable fact that twentieth-century molecular biology developed its conceptual system on the basis of sign-like terms has been the object of numerous studies and debates. Throughout these, the assumption is made that this vocabulary's emergence should be seen in the historical context of mathematical communication theory and cybernetics. This paper, in contrast, sets out the need for a more differentiated view: whereas the success of the terms "code" and "information" would probably be unthinkable outside that historical context, general semiotic and especially scriptural concepts arose far earlier in the "prehistory" of molecular biology, and in close association with biological research and phenomena. This distinction, established through a reconstruction of conceptual developments between 1870 and 1950, makes it possible to separate off a critique of the reductive implications of particular information-based concepts from the use of semiotic and scriptural concepts, which is fundamental to molecular biology. Gene-centrism and determinism are not implications of semiotic and scriptural analogies, but arose only when the vocabulary of information was superimposed upon them.

The contribution of neutron scattering to molecular biology

International Nuclear Information System (INIS)

Stuhrmann, H.B.

1983-01-01

About half of the atoms of living cells are hydrogens, and nearly all biological applications of neutron scattering rely on the well-known difference in the scattering lengths of the proton and the deuteron. This introduces us to a wide variety of biological problems, which are related with hydrogen in water, proteins, nucleic acids and lipids. Neutron scattering gives an answer to both structural and dynamical aspects of the system in question. With deuterium labelled samples unambiguous information about molecular structure and motion becomes accessible. The architecture of viruses, cell membranes and gene expressing molecules has become a lot clearer with neutron scattering. (author)

Physics and the molecular revolution in plant biology: union needed for managing the future

Directory of Open Access Journals (Sweden)

Ulrich Lüttge

2016-10-01

Full Text Available The question was asked if there is still a prominent role of biophysics in plant biology in an age when molecular biology appears to be dominating. Mathematical formation of theory is essential in systems biology, and mathematics is more inherent in biophysics than in molecular biology. A survey is made identifying and briefly characterizing fields of plant biology where approaches of biophysics remain essential. In transport at membranes electrophysiology and thermodynamics are biophysical topics. Water is a special molecule. Its transport follows the physical laws of osmosis and gradients of water potential on the background of physics of hydraulic architecture. Photobiology needs understanding of the physics of electro-magnetic radiation of quantitative nature in photosynthesis and of qualitative nature in perception by the photo-sensors cryptochromes, phototropins and phytochrome in environmental responses and development. Biophysical oscillators can play a role in biological timing by the circadian clock. Integration in the self-organization of modules, such as roots, stems and leaves, for the emergence of whole plants as unitary organisms needs storage and transport of information where physical modes of signaling are essential with cross talks between electrical and hydraulic signals and with chemical signals. Examples are gravitropism and root-shoot interactions in water relations. All of these facets of plant biophysics overlie plant molecular biology and exchange with it. It is advocated that a union of approaches of plant molecular biology and biophysics needs to be cultivated. In many cases it is already operative. In bionics biophysics is producing output for practical applications linking biology with technology. Biomimetic engineering intrinsically uses physical approaches. An extreme biophysical perspective is looking out for life in space. Sustained and increased practice of biophysics with teaching and research deserves strong

Dissecting the Molecular Mechanisms of Neurodegenerative Diseases through Network Biology

Directory of Open Access Journals (Sweden)

Jose A. Santiago

2017-05-01

Full Text Available Neurodegenerative diseases are rarely caused by a mutation in a single gene but rather influenced by a combination of genetic, epigenetic and environmental factors. Emerging high-throughput technologies such as RNA sequencing have been instrumental in deciphering the molecular landscape of neurodegenerative diseases, however, the interpretation of such large amounts of data remains a challenge. Network biology has become a powerful platform to integrate multiple omics data to comprehensively explore the molecular networks in the context of health and disease. In this review article, we highlight recent advances in network biology approaches with an emphasis in brain-networks that have provided insights into the molecular mechanisms leading to the most prevalent neurodegenerative diseases including Alzheimer’s (AD, Parkinson’s (PD and Huntington’s diseases (HD. We discuss how integrative approaches using multi-omics data from different tissues have been valuable for identifying biomarkers and therapeutic targets. In addition, we discuss the challenges the field of network medicine faces toward the translation of network-based findings into clinically actionable tools for personalized medicine applications.

Naumovozyma castellii: an alternative model for budding yeast molecular biology.

Science.gov (United States)

Karademir Andersson, Ahu; Cohn, Marita

2017-03-01

Naumovozyma castellii (Saccharomyces castellii) is a member of the budding yeast family Saccharomycetaceae. It has been extensively used as a model organism for telomere biology research and has gained increasing interest as a budding yeast model for functional analyses owing to its amenability to genetic modifications. Owing to the suitable phylogenetic distance to S. cerevisiae, the whole genome sequence of N. castellii has provided unique data for comparative genomic studies, and it played a key role in the establishment of the timing of the whole genome duplication and the evolutionary events that took place in the subsequent genomic evolution of the Saccharomyces lineage. Here we summarize the historical background of its establishment as a laboratory yeast species, and the development of genetic and molecular tools and strains. We review the research performed on N. castellii, focusing on areas where it has significantly contributed to the discovery of new features of molecular biology and to the advancement of our understanding of molecular evolution. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Future directions for radiological physics: An interface with molecular biology

International Nuclear Information System (INIS)

Braby, L.A.

1987-01-01

Recent experiments with low energy x-rays and fast molecular ions have shown that the products of the interaction of several ionizations within a few nanometers dominate radiation effects. However, the authors still can only make assumptions about the physical and chemical nature of this initial damage. Enzymatic repair of DNA damage is another key factor, but they have little idea of what governs the success or failure (misrepair) of these processes. Unresolved problems like these dictate the future direction of radiological physics. Molecular biology techniques are being applied to determine molecular alterations which result in observed damage. Interpretation of these experiments will require new data on the physics of energy transfer to macromolecules and the stochastics of energy deposition in time. Future studies will attempt to identify the initial damage, before biological processes have amplified it. This will require a detailed understanding of the role of chromatin structure in governing gene expression, the transport of energy within macromolecules, the transport of ions and radicals in the semiordered environment near DNA strands, and many other physical characteristics within the living cell

How phenotypic plasticity made its way into molecular biology

Indian Academy of Sciences (India)

2009-08-03

Aug 3, 2009 ... Phenotypic plasticity has been fashionable in recent years. It has never been absent from the studies of evolutionary biologists, although the availability of stable animal models has limited its role. Although opposed by the reductionist and deterministic approach of molecular biology, phenotypic plasticity ...

Implications of molecular heterogeneity for the cooperativity of biological macromolecules.

Science.gov (United States)

Solomatin, Sergey V; Greenfeld, Max; Herschlag, Daniel

2011-06-01

Cooperativity, a universal property of biological macromolecules, is typically characterized by a Hill slope, which can provide fundamental information about binding sites and interactions. We demonstrate, through simulations and single-molecule FRET (smFRET) experiments, that molecular heterogeneity lowers bulk cooperativity from the intrinsic value for the individual molecules. As heterogeneity is common in smFRET experiments, appreciation of its influence on fundamental measures of cooperativity is critical for deriving accurate molecular models.

Application of quasi-steady state methods to molecular motor transport on microtubules in fungal hyphae.

Science.gov (United States)

Dauvergne, Duncan; Edelstein-Keshet, Leah

2015-08-21

We consider bidirectional transport of cargo by molecular motors dynein and kinesin that walk along microtubules, and/or diffuse in the cell. The motors compete to transport cargo in opposite directions with respect to microtubule polarity (towards the plus or minus end of the microtubule). In recent work, Gou et al. (2014) used a hierarchical set of models, each consisting of continuum transport equations to track the evolution of motors and their cargo (early endosomes) in the specific case of the fungus Ustilago maydis. We complement their work using a framework of quasi-steady state analysis developed by Newby and Bressloff (2010) and Bressloff and Newby (2013) to reduce the models to an approximating steady state Fokker-Plank equation. This analysis allows us to find analytic approximations to the steady state solutions in many cases where the full models are not easily solved. Consequently, we can make predictions about parameter dependence of the resulting spatial distributions. We also characterize the overall rates of bulk transport and diffusion, and how these are related to state transition parameters, motor speeds, microtubule polarity distribution, and specific assumptions made. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Role of Molecular Microtubule Motors and the Microtubule Cytoskeleton in Stress Granule Dynamics

Directory of Open Access Journals (Sweden)

Kristen M. Bartoli

2011-01-01

Full Text Available Stress granules (SGs are cytoplasmic foci that appear in cells exposed to stress-induced translational inhibition. SGs function as a triage center, where mRNAs are sorted for storage, degradation, and translation reinitiation. The underlying mechanisms of SGs dynamics are still being characterized, although many key players have been identified. The main components of SGs are stalled 48S preinitiation complexes. To date, many other proteins have also been found to localize in SGs and are hypothesized to function in SG dynamics. Most recently, the microtubule cytoskeleton and associated motor proteins have been demonstrated to function in SG dynamics. In this paper, we will discuss current literature examining the function of microtubules and the molecular microtubule motors in SG assembly, coalescence, movement, composition, organization, and disassembly.

Epidemiology and Molecular Biology of Head and Neck Cancer.

Science.gov (United States)

Jou, Adriana; Hess, Jochen

2017-01-01

Head and neck cancer is a common and aggressive malignancy with a high morbidity and mortality profile. Although the large majority of cases resemble head and neck squamous cell carcinoma (HNSCC), the current classification based on anatomic site and tumor stage fails to capture the high level of biologic heterogeneity, and appropriate clinical management remains a major challenge. Hence, a better understanding of the molecular biology of HNSCC is urgently needed to support biomarker development and personalized care for patients. This review focuses on recent findings based on integrative genomics analysis and multi-scale modeling approaches and how they are beginning to provide more sophisticated clues as to the biological and clinical diversity of HNSCC. © 2017 S. Karger GmbH, Freiburg.

In vitro studies. Contribution of radioactive marking to molecular biology development

International Nuclear Information System (INIS)

Sentenac, A.

1997-01-01

The spectacular and rapid development of molecular biology is essentially related to the utilization of marked molecules which leads to quantitative and qualitative information; the use of radioactive tracers allowed for the observation of the biosynthesis of biological polymers, and thus, for example, the formation of DNA, RNA or proteins. A historical review of the great discoveries in this field, is presented

Panel 4: Recent Advances in Otitis Media in Molecular Biology, Biochemistry, Genetics, and Animal Models

Science.gov (United States)

Li, Jian-Dong; Hermansson, Ann; Ryan, Allen F.; Bakaletz, Lauren O.; Brown, Steve D.; Cheeseman, Michael T.; Juhn, Steven K.; Jung, Timothy T. K.; Lim, David J.; Lim, Jae Hyang; Lin, Jizhen; Moon, Sung-Kyun; Post, J. Christopher

2014-01-01

Background Otitis media (OM) is the most common childhood bacterial infection and also the leading cause of conductive hearing loss in children. Currently, there is an urgent need for developing novel therapeutic agents for treating OM based on full understanding of molecular pathogenesis in the areas of molecular biology, biochemistry, genetics, and animal model studies in OM. Objective To provide a state-of-the-art review concerning recent advances in OM in the areas of molecular biology, biochemistry, genetics, and animal model studies and to discuss the future directions of OM studies in these areas. Data Sources and Review Methods A structured search of the current literature (since June 2007). The authors searched PubMed for published literature in the areas of molecular biology, biochemistry, genetics, and animal model studies in OM. Results Over the past 4 years, significant progress has been made in the areas of molecular biology, biochemistry, genetics, and animal model studies in OM. These studies brought new insights into our understanding of the molecular and biochemical mechanisms underlying the molecular pathogenesis of OM and helped identify novel therapeutic targets for OM. Conclusions and Implications for Practice Our understanding of the molecular pathogenesis of OM has been significantly advanced, particularly in the areas of inflammation, innate immunity, mucus overproduction, mucosal hyperplasia, middle ear and inner ear interaction, genetics, genome sequencing, and animal model studies. Although these studies are still in their experimental stages, they help identify new potential therapeutic targets. Future preclinical and clinical studies will help to translate these exciting experimental research findings into clinical applications. PMID:23536532

Driving Unidirectional Molecular Rotary Motors with Visible Light by Intra- And Intermolecular Energy Transfer from Palladium Porphyrin

NARCIS (Netherlands)

Cnossen, Arjen; Hou, Lili; Pollard, Michael M.; Wesenhagen, Philana V.; Browne, Wesley R.; Feringa, Ben L.

2012-01-01

Driving molecular rotary motors using visible light (530-550 nm) instead of UV light was achieved using palladium tetraphenylporphyrin as a triplet sensitizer. Visible light driven rotation was confirmed by UV/vis absorption, circular dichroism and H-1 NMR spectroscopy and the rotation was confirmed

Planetary Biology and Microbial Ecology: Molecular Ecology and the Global Nitrogen cycle

Science.gov (United States)

Nealson, Molly Stone (Editor); Nealson, Kenneth H. (Editor)

1993-01-01

This report summarizes the results of the Planetary Biology and Molecular Ecology's summer 1991 program, which was held at the Marine Biological Laboratory in Woods Hole, Massachusetts. The purpose of the interdisciplinary PBME program is to integrate, via lectures and laboratory work, the contributions of university and NASA scientists and student interns. The goals of the 1991 program were to examine several aspects of the biogeochemistry of the nitrogen cycle and to teach the application of modern methods of molecular genetics to field studies of organisms. Descriptions of the laboratory projects and protocols and abstracts and references of the lectures are presented.

Robust transport by multiple motors with nonlinear force–velocity relations and stochastic load sharing

International Nuclear Information System (INIS)

Kunwar, Ambarish; Mogilner, Alexander

2010-01-01

Transport by processive molecular motors plays an important role in many cell biological phenomena. In many cases, motors work together to transport cargos in the cell, so it is important to understand the mechanics of the multiple motors. Based on earlier modeling efforts, here we study effects of nonlinear force–velocity relations and stochastic load sharing on multiple motor transport. We find that when two or three motors transport the cargo, then the nonlinear and stochastic effects compensate so that the mechanical properties of the transport are robust. Similarly, the transport is insensitive to compliance of the cargo-motor links. Furthermore, the rate of movement against moderate loads is not improved by increasing the small number of motors. When the motor number is greater than 4, correlations between the motors become negligible, and the earlier analytical mean-field theory of the multiple motor transport holds. We predict that the effective diffusion of the cargo driven by the multiple motors under load increases by an order of magnitude compared to that for the single motor. Finally, our simulations predict that the stochastic effects are responsible for a significant dispersion of velocities generated by the 'tug-of-war' of the multiple opposing motors

Multispectral optical tweezers for molecular diagnostics of single biological cells

Science.gov (United States)

Butler, Corey; Fardad, Shima; Sincore, Alex; Vangheluwe, Marie; Baudelet, Matthieu; Richardson, Martin

2012-03-01

Optical trapping of single biological cells has become an established technique for controlling and studying fundamental behavior of single cells with their environment without having "many-body" interference. The development of such an instrument for optical diagnostics (including Raman and fluorescence for molecular diagnostics) via laser spectroscopy with either the "trapping" beam or secondary beams is still in progress. This paper shows the development of modular multi-spectral imaging optical tweezers combining Raman and Fluorescence diagnostics of biological cells.

A catalytic oligomeric motor that walks along a filament track

Energy Technology Data Exchange (ETDEWEB)

Huang, Mu-Jie, E-mail: mjhuang@chem.utoronto.ca; Kapral, Raymond, E-mail: rkapral@chem.utoronto.ca [Chemical Physics Theory Group, Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6 (Canada)

2015-06-28

Most biological motors in the cell execute chemically powered conformational changes as they walk on biopolymer filaments in order to carry out directed transport functions. Synthetic motors that operate in a similar manner are being studied since they have the potential to perform similar tasks in a variety of applications. In this paper, a synthetic nanomotor that moves along a filament track, without invoking motor conformational changes, is constructed and its properties are studied in detail. The motor is an oligomer comprising three linked beads with specific binding properties. The filament track is a stiff polymer chain, also described by a linear chain of linked coarse-grained molecular groups modeled as beads. Reactions on the filament that are catalyzed by a motor bead and use fuel in the environment, in conjunction within the binding affinities of the motor beads to the filament beads, lead to directed motion. The system operates out of equilibrium due to the state of the filament and supply of fuel. The motor, filament, and surrounding medium are all described at microscopic level that permits a full analysis of the motor motion. A stochastic model that captures the main trends seen in the simulations is also presented. The results of this study point to some of the key features that could be used to construct nanomotors that undergo biased walks powered by chemical reactions on filaments.

A catalytic oligomeric motor that walks along a filament track

Science.gov (United States)

Huang, Mu-Jie; Kapral, Raymond

2015-06-01

Most biological motors in the cell execute chemically powered conformational changes as they walk on biopolymer filaments in order to carry out directed transport functions. Synthetic motors that operate in a similar manner are being studied since they have the potential to perform similar tasks in a variety of applications. In this paper, a synthetic nanomotor that moves along a filament track, without invoking motor conformational changes, is constructed and its properties are studied in detail. The motor is an oligomer comprising three linked beads with specific binding properties. The filament track is a stiff polymer chain, also described by a linear chain of linked coarse-grained molecular groups modeled as beads. Reactions on the filament that are catalyzed by a motor bead and use fuel in the environment, in conjunction within the binding affinities of the motor beads to the filament beads, lead to directed motion. The system operates out of equilibrium due to the state of the filament and supply of fuel. The motor, filament, and surrounding medium are all described at microscopic level that permits a full analysis of the motor motion. A stochastic model that captures the main trends seen in the simulations is also presented. The results of this study point to some of the key features that could be used to construct nanomotors that undergo biased walks powered by chemical reactions on filaments.

A catalytic oligomeric motor that walks along a filament track

International Nuclear Information System (INIS)

Huang, Mu-Jie; Kapral, Raymond

2015-01-01

Most biological motors in the cell execute chemically powered conformational changes as they walk on biopolymer filaments in order to carry out directed transport functions. Synthetic motors that operate in a similar manner are being studied since they have the potential to perform similar tasks in a variety of applications. In this paper, a synthetic nanomotor that moves along a filament track, without invoking motor conformational changes, is constructed and its properties are studied in detail. The motor is an oligomer comprising three linked beads with specific binding properties. The filament track is a stiff polymer chain, also described by a linear chain of linked coarse-grained molecular groups modeled as beads. Reactions on the filament that are catalyzed by a motor bead and use fuel in the environment, in conjunction within the binding affinities of the motor beads to the filament beads, lead to directed motion. The system operates out of equilibrium due to the state of the filament and supply of fuel. The motor, filament, and surrounding medium are all described at microscopic level that permits a full analysis of the motor motion. A stochastic model that captures the main trends seen in the simulations is also presented. The results of this study point to some of the key features that could be used to construct nanomotors that undergo biased walks powered by chemical reactions on filaments

Systems Biology-Driven Hypotheses Tested In Vivo: The Need to Advancing Molecular Imaging Tools.

Science.gov (United States)

Verma, Garima; Palombo, Alessandro; Grigioni, Mauro; La Monaca, Morena; D'Avenio, Giuseppe

2018-01-01

Processing and interpretation of biological images may provide invaluable insights on complex, living systems because images capture the overall dynamics as a "whole." Therefore, "extraction" of key, quantitative morphological parameters could be, at least in principle, helpful in building a reliable systems biology approach in understanding living objects. Molecular imaging tools for system biology models have attained widespread usage in modern experimental laboratories. Here, we provide an overview on advances in the computational technology and different instrumentations focused on molecular image processing and analysis. Quantitative data analysis through various open source software and algorithmic protocols will provide a novel approach for modeling the experimental research program. Besides this, we also highlight the predictable future trends regarding methods for automatically analyzing biological data. Such tools will be very useful to understand the detailed biological and mathematical expressions under in-silico system biology processes with modeling properties.

Molecular biology of the lung cancer

International Nuclear Information System (INIS)

Panov, S.Z.

2005-01-01

Background. Lung cancer is one of the most common malignant diseases and leading cause of cancer death worldwide. The advances in molecular biology and genetics, including the modern microarray technology and rapid sequencing techniques, have enabled a remarkable progress into elucidating the lung cancer ethiopathogenesis. Numerous studies suggest that more than 20 different genetic and epigenetic alterations are accumulating during the pathogenesis of clinically evident pulmonary cancers as a clonal, multistep process. Thus far, the most investigated alterations are the inactivational mutations and losses of tumour suppressor genes and the overexpression of growth-promoting oncogenes. More recently, the acquired epigenetic inactivation of tumour suppressor genes by promoter hypermethylation has been recognized. The early clonal genetic abnormalities that occur in preneoplastic bronchial epithelium damaged by smoking or other carcinogenes are being identified. The molecular distinctions between small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC), as well as between tumors with different clinical outcomes have been described. These investigations lead to the h allmarks of lung cancer . Conclusions. It is realistic to expect that the molecular and cell culture-based investigations will lead to discoveries of new clinical applications with the potential to provide new avenues for early diagnosis, risk assessment, prevention, and most important, new more effective treatment approaches for the lung cancer patients. (author)

Frontiers in nuclear medicine symposium: Nuclear medicine & molecular biology

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-04-01

This document contains the abstracts from the American College of Nuclear Physicians 1993 Fall Meeting entitled, `Frontiers in Nuclear Medicine Symposium: Nuclear Medicine and Molecular Biology`. This meeting was sponsored by the US DOE, Office of Health and Environmental Research, Office of Energy Research. The program chairman was Richard C. Reba, M.D.

Biology, Bionomics and Molecular Biology of Anopheles sinensis Wiedemann 1828 (Diptera: Culicidae), Main Malaria Vector in China.

Science.gov (United States)

Feng, Xinyu; Zhang, Shaosen; Huang, Fang; Zhang, Li; Feng, Jun; Xia, Zhigui; Zhou, Hejun; Hu, Wei; Zhou, Shuisen

2017-01-01

China has set a goal to eliminate all malaria in the country by 2020, but it is unclear if current understanding of malaria vectors and transmission is sufficient to achieve this objective. Anopheles sinensis is the most widespread malaria vector specie in China, which is also responsible for vivax malaria outbreak in central China. We reviewed literature from 1954 to 2016 on An. sinensis with emphasis on biology, bionomics, and molecular biology. A total of 538 references were relevant and included. An. sienesis occurs in 29 Chinese provinces. Temperature can affect most life-history parameters. Most An. sinensis are zoophilic, but sometimes they are facultatively anthropophilic. Sporozoite analysis demonstrated An. sinensis efficacy on Plasmodium vivax transmission. An. sinensis was not stringently refractory to P. falciparum under experimental conditions, however, sporozoite was not found in salivary glands of field collected An. sinensis . The literature on An. sienesis biology and bionomics was abundant, but molecular studies, such as gene functions and mechanisms, were limited. Only 12 molecules (genes, proteins or enzymes) have been studied. In addition, there were considerable untapped omics resources for potential vector control tools. Existing information on An. sienesis could serve as a baseline for advanced research on biology, bionomics and genetics relevant to vector control strategies.

A Comprehensive Experiment for Molecular Biology: Determination of Single Nucleotide Polymorphism in Human REV3 Gene Using PCR-RFLP

Science.gov (United States)

Zhang, Xu; Shao, Meng; Gao, Lu; Zhao, Yuanyuan; Sun, Zixuan; Zhou, Liping; Yan, Yongmin; Shao, Qixiang; Xu, Wenrong; Qian, Hui

2017-01-01

Laboratory exercise is helpful for medical students to understand the basic principles of molecular biology and to learn about the practical applications of molecular biology. We have designed a lab course on molecular biology about the determination of single nucleotide polymorphism (SNP) in human REV3 gene, the product of which is a subunit of…

A comprehensive experiment for molecular biology: Determination of single nucleotide polymorphism in human REV3 gene using PCR-RFLP.

Science.gov (United States)

Zhang, Xu; Shao, Meng; Gao, Lu; Zhao, Yuanyuan; Sun, Zixuan; Zhou, Liping; Yan, Yongmin; Shao, Qixiang; Xu, Wenrong; Qian, Hui

2017-07-08

Laboratory exercise is helpful for medical students to understand the basic principles of molecular biology and to learn about the practical applications of molecular biology. We have designed a lab course on molecular biology about the determination of single nucleotide polymorphism (SNP) in human REV3 gene, the product of which is a subunit of DNA polymerase ζ and SNPs in this gene are associated with altered susceptibility to cancer. This newly designed experiment is composed of three parts, including genomic DNA extraction, gene amplification by PCR, and genotyping by RFLP. By combining these activities, the students are not only able to learn a series of biotechniques in molecular biology, but also acquire the ability to link the learned knowledge with practical applications. This comprehensive experiment will help the medical students improve the conceptual understanding of SNP and the technical understanding of SNP detection. © 2017 by The International Union of Biochemistry and Molecular Biology, 45(4):299-304, 2017. © 2017 The International Union of Biochemistry and Molecular Biology.

The biochemistry and molecular biology of xenobiotic polymer degradation by microorganisms.

Science.gov (United States)

Kawai, Fusako

2010-01-01

Research on microbial degradation of xenobiotic polymers has been underway for more than 40 years. It has exploited a new field not only in applied microbiology but also in environmental microbiology, and has greatly contributed to polymer science by initiating the design of biodegradable polymers. Owing to the development of analytical tools and technology, molecular biological and biochemical advances have made it possible to prospect for degrading microorganisms in the environment and to determine the mechanisms involved in biodegradation when xenobiotic polymers are introduced into the environment and are exposed to microbial attack. In this review, the molecular biological and biochemical aspects of the microbial degradation of xenobiotic polymers are summarized, and possible applications of potent microorganisms, enzymes, and genes in environmental biotechnology are suggested.

Structural insight into RNA recognition motifs: versatile molecular Lego building blocks for biological systems.

Science.gov (United States)

Muto, Yutaka; Yokoyama, Shigeyuki

2012-01-01

'RNA recognition motifs (RRMs)' are common domain-folds composed of 80-90 amino-acid residues in eukaryotes, and have been identified in many cellular proteins. At first they were known as RNA binding domains. Through discoveries over the past 20 years, however, the RRMs have been shown to exhibit versatile molecular recognition activities and to behave as molecular Lego building blocks to construct biological systems. Novel RNA/protein recognition modes by RRMs are being identified, and more information about the molecular recognition by RRMs is becoming available. These RNA/protein recognition modes are strongly correlated with their biological significance. In this review, we would like to survey the recent progress on these versatile molecular recognition modules. Copyright © 2012 John Wiley & Sons, Ltd.

Barrett's esophagus: cancer and molecular biology.

Science.gov (United States)

Gibson, Michael K; Dhaliwal, Arashinder S; Clemons, Nicholas J; Phillips, Wayne A; Dvorak, Katerina; Tong, Daniel; Law, Simon; Pirchi, E Daniel; Räsänen, Jari; Krasna, Mark J; Parikh, Kaushal; Krishnadath, Kausilia K; Chen, Yu; Griffiths, Leonard; Colleypriest, Benjamin J; Farrant, J Mark; Tosh, David; Das, Kiron M; Bajpai, Manisha

2013-10-01

The following paper on the molecular biology of Barrett's esophagus (BE) includes commentaries on signaling pathways central to the development of BE including Hh, NF-κB, and IL-6/STAT3; surgical approaches for esophagectomy and classification of lesions by appropriate therapy; the debate over the merits of minimally invasive esophagectomy versus open surgery; outcomes for patients with pharyngolaryngoesophagectomy; the applications of neoadjuvant chemotherapy and chemoradiotherapy; animal models examining the surgical models of BE and esophageal adenocarcinoma; the roles of various morphogens and Cdx2 in BE; and the use of in vitro BE models for chemoprevention studies. © 2013 New York Academy of Sciences.

Genetics and molecular biology of hypotension

Science.gov (United States)

Robertson, D.

1994-01-01

Major strides in the molecular biology of essential hypertension are currently underway. This has tended to obscure the fact that a number of inherited disorders associated with low blood pressure exist and that these diseases may have milder and underrecognized phenotypes that contribute importantly to blood pressure variation in the general population. This review highlights some of the gene products that, if abnormal, could cause hypotension in some individuals. Diseases due to abnormalities in the catecholamine enzymes are discussed in detail. It is likely that genetic abnormalities with hypotensive phenotypes will be as interesting and diverse as those that give rise to hypertensive disorders.

Quasi-steady State Reduction of Molecular Motor-Based Models of Directed Intermittent Search

KAUST Repository

Newby, Jay M.

2010-02-19

We present a quasi-steady state reduction of a linear reaction-hyperbolic master equation describing the directed intermittent search for a hidden target by a motor-driven particle moving on a one-dimensional filament track. The particle is injected at one end of the track and randomly switches between stationary search phases and mobile nonsearch phases that are biased in the anterograde direction. There is a finite possibility that the particle fails to find the target due to an absorbing boundary at the other end of the track. Such a scenario is exemplified by the motor-driven transport of vesicular cargo to synaptic targets located on the axon or dendrites of a neuron. The reduced model is described by a scalar Fokker-Planck (FP) equation, which has an additional inhomogeneous decay term that takes into account absorption by the target. The FP equation is used to compute the probability of finding the hidden target (hitting probability) and the corresponding conditional mean first passage time (MFPT) in terms of the effective drift velocity V, diffusivity D, and target absorption rate λ of the random search. The quasi-steady state reduction determines V, D, and λ in terms of the various biophysical parameters of the underlying motor transport model. We first apply our analysis to a simple 3-state model and show that our quasi-steady state reduction yields results that are in excellent agreement with Monte Carlo simulations of the full system under physiologically reasonable conditions. We then consider a more complex multiple motor model of bidirectional transport, in which opposing motors compete in a "tug-of-war", and use this to explore how ATP concentration might regulate the delivery of cargo to synaptic targets. © 2010 Society for Mathematical Biology.

Using Whole Mount in situ Hybridization to Link Molecular and Organismal Biology

OpenAIRE

Jacobs, Nicole L.; Albertson, R. Craig; Wiles, Jason R.

2011-01-01

Whole mount in situ hybridization (WISH) is a common technique in molecular biology laboratories used to study gene expression through the localization of specific mRNA transcripts within whole mount specimen. This technique (adapted from Albertson and Yelick, 2005) was used in an upper level undergraduate Comparative Vertebrate Biology laboratory classroom at Syracuse University. The first two thirds of the Comparative Vertebrate Biology lab course gave students the opportunity to study the ...

Transplantation of Xenopus laevis tissues to determine the ability of motor neurons to acquire a novel target.

Directory of Open Access Journals (Sweden)

Karen L Elliott

Full Text Available The evolutionary origin of novelties is a central problem in biology. At a cellular level this requires, for example, molecularly resolving how brainstem motor neurons change their innervation target from muscle fibers (branchial motor neurons to neural crest-derived ganglia (visceral motor neurons or ear-derived hair cells (inner ear and lateral line efferent neurons. Transplantation of various tissues into the path of motor neuron axons could determine the ability of any motor neuron to innervate a novel target. Several tissues that receive direct, indirect, or no motor innervation were transplanted into the path of different motor neuron populations in Xenopus laevis embryos. Ears, somites, hearts, and lungs were transplanted to the orbit, replacing the eye. Jaw and eye muscle were transplanted to the trunk, replacing a somite. Applications of lipophilic dyes and immunohistochemistry to reveal motor neuron axon terminals were used. The ear, but not somite-derived muscle, heart, or liver, received motor neuron axons via the oculomotor or trochlear nerves. Somite-derived muscle tissue was innervated, likely by the hypoglossal nerve, when replacing the ear. In contrast to our previous report on ear innervation by spinal motor neurons, none of the tissues (eye or jaw muscle was innervated when transplanted to the trunk. Taken together, these results suggest that there is some plasticity inherent to motor innervation, but not every motor neuron can become an efferent to any target that normally receives motor input. The only tissue among our samples that can be innervated by all motor neurons tested is the ear. We suggest some possible, testable molecular suggestions for this apparent uniqueness.

Cells from icons to symbols: molecularizing cell biology in the 1980s.

Science.gov (United States)

Serpente, Norberto

2011-12-01

Over centuries cells have been the target of optical and electronic microscopes as well as others technologies, with distinctive types of visual output. Whilst optical technologies produce images 'evident to the eye', the electronic and especially the molecular create images that are more elusive to conceptualization and assessment. My study applies the semiotic approach to the production of images in cell biology to capture the shift from microscopic images to non-traditional visual technologies around 1980. Here I argue that the visual shift that coincides with the growing dominance of molecular biology involves a change from iconic to symbolic forms. Copyright © 2011 Elsevier Ltd. All rights reserved.

A Model of How Different Biology Experts Explain Molecular and Cellular Mechanisms

Science.gov (United States)

Trujillo, Caleb M.; Anderson, Trevor R.; Pelaez, Nancy J.

2015-01-01

Constructing explanations is an essential skill for all science learners. The goal of this project was to model the key components of expert explanation of molecular and cellular mechanisms. As such, we asked: What is an appropriate model of the components of explanation used by biology experts to explain molecular and cellular mechanisms? Do…

The diverse and expanding role of mass spectrometry in structural and molecular biology.

Science.gov (United States)

Lössl, Philip; van de Waterbeemd, Michiel; Heck, Albert Jr

2016-12-15

The emergence of proteomics has led to major technological advances in mass spectrometry (MS). These advancements not only benefitted MS-based high-throughput proteomics but also increased the impact of mass spectrometry on the field of structural and molecular biology. Here, we review how state-of-the-art MS methods, including native MS, top-down protein sequencing, cross-linking-MS, and hydrogen-deuterium exchange-MS, nowadays enable the characterization of biomolecular structures, functions, and interactions. In particular, we focus on the role of mass spectrometry in integrated structural and molecular biology investigations of biological macromolecular complexes and cellular machineries, highlighting work on CRISPR-Cas systems and eukaryotic transcription complexes. © 2016 The Authors. Published under the terms of the CC BY NC ND 4.0 license.

Mathematical Biology Modules Based on Modern Molecular Biology and Modern Discrete Mathematics

Science.gov (United States)

Davies, Robin; Hodge, Terrell; Enyedi, Alexander

2010-01-01

We describe an ongoing collaborative curriculum materials development project between Sweet Briar College and Western Michigan University, with support from the National Science Foundation. We present a collection of modules under development that can be used in existing mathematics and biology courses, and we address a critical national need to introduce students to mathematical methods beyond the interface of biology with calculus. Based on ongoing research, and designed to use the project-based-learning approach, the modules highlight applications of modern discrete mathematics and algebraic statistics to pressing problems in molecular biology. For the majority of projects, calculus is not a required prerequisite and, due to the modest amount of mathematical background needed for some of the modules, the materials can be used for an early introduction to mathematical modeling. At the same time, most modules are connected with topics in linear and abstract algebra, algebraic geometry, and probability, and they can be used as meaningful applied introductions into the relevant advanced-level mathematics courses. Open-source software is used to facilitate the relevant computations. As a detailed example, we outline a module that focuses on Boolean models of the lac operon network. PMID:20810955

Mathematical biology modules based on modern molecular biology and modern discrete mathematics.

Science.gov (United States)

Robeva, Raina; Davies, Robin; Hodge, Terrell; Enyedi, Alexander

2010-01-01

We describe an ongoing collaborative curriculum materials development project between Sweet Briar College and Western Michigan University, with support from the National Science Foundation. We present a collection of modules under development that can be used in existing mathematics and biology courses, and we address a critical national need to introduce students to mathematical methods beyond the interface of biology with calculus. Based on ongoing research, and designed to use the project-based-learning approach, the modules highlight applications of modern discrete mathematics and algebraic statistics to pressing problems in molecular biology. For the majority of projects, calculus is not a required prerequisite and, due to the modest amount of mathematical background needed for some of the modules, the materials can be used for an early introduction to mathematical modeling. At the same time, most modules are connected with topics in linear and abstract algebra, algebraic geometry, and probability, and they can be used as meaningful applied introductions into the relevant advanced-level mathematics courses. Open-source software is used to facilitate the relevant computations. As a detailed example, we outline a module that focuses on Boolean models of the lac operon network.

Semester-long inquiry-based molecular biology laboratory: Transcriptional regulation in yeast.

Science.gov (United States)

Oelkers, Peter M

2017-03-04

A single semester molecular biology laboratory has been developed in which students design and execute a project examining transcriptional regulation in Saccharomyces cerevisiae. Three weeks of planning are allocated to developing a hypothesis through literature searches and use of bioinformatics. Common experimental plans address a cell process and how three genes that encode for proteins involved in that process are transcriptionally regulated in response to changing environmental conditions. Planning includes designing oligonucleotides to amplify the putative promoters of the three genes of interest. After the PCR, each product is cloned proximal to β-galactosidase in a yeast reporter plasmid. Techniques used include agarose electrophoresis, extraction of DNA from agarose, plasmid purification from bacteria, restriction digestion, ligation, and bacterial transformation. This promoter/reporter plasmid is then transformed into yeast. Transformed yeast are cultured in conditions prescribed in the experimental design, lysed and β-galactosidase activity is measured. The course provides an independent research experience in a group setting. Notebooks are maintained on-line with regular feedback. Projects culminate with the presentation of a poster worth 60% of the grade. Over the last three years, about 65% of students met expectations for experimental design, data acquisition, and analysis. © 2016 by The International Union of Biochemistry and Molecular Biology, 45(2):145-151, 2017. © 2016 The International Union of Biochemistry and Molecular Biology.

Dysregulation of RNA Mediated Gene Expression in Motor Neuron Diseases.

Science.gov (United States)

Gonçalves, Inês do Carmo G; Rehorst, Wiebke A; Kye, Min Jeong

2016-01-01

Recent findings indicate an important role for RNA-mediated gene expression in motor neuron diseases, including ALS (amyotrophic lateral sclerosis) and SMA (spinal muscular atrophy). ALS, also known as Lou Gehrig's disease, is an adult-onset progressive neurodegenerative disorder, whereby SMA or "children's Lou Gehrig's disease" is considered a pediatric neurodevelopmental disorder. Despite the difference in genetic causes, both ALS and SMA share common phenotypes; dysfunction/loss of motor neurons that eventually leads to muscle weakness and atrophy. With advanced techniques in molecular genetics and cell biology, current data suggest that these two distinct motor neuron diseases share more than phenotypes; ALS and SMA have similar cellular pathological mechanisms including mitochondrial dysfunction, oxidative stress and dysregulation in RNA-mediated gene expression. Here, we will discuss the current findings on these two diseases with specific focus on RNA-mediated gene regulation including miRNA expression, pre-mRNA processing and RNA binding proteins.

Molecular biological aspects of acquired bullous diseases

DEFF Research Database (Denmark)

Dabelsteen, Erik

1998-01-01

Bullous diseases of the oral mucosa and skin were originally classified on the basis of clinical and histological criteria. The discovery of autoantibodies in some of these patients and the introduction of molecular biology have resulted in a new understanding of the pathological mechanisms of many...... of the bullous lesions. In this article, updated topics of the immune-mediated bullous lesions which involve oral mucosa and skin are reviewed. Pemphigus antigens, which are desmosomal-associated proteins and belong to the cadherin superfamily of cell adhesion proteins, have been isolated, and their genes have...

An all-electric single-molecule motor.

Science.gov (United States)

Seldenthuis, Johannes S; Prins, Ferry; Thijssen, Joseph M; van der Zant, Herre S J

2010-11-23

Many types of molecular motors have been proposed and synthesized in recent years, displaying different kinds of motion, and fueled by different driving forces such as light, heat, or chemical reactions. We propose a new type of molecular motor based on electric field actuation and electric current detection of the rotational motion of a molecular dipole embedded in a three-terminal single-molecule device. The key aspect of this all-electronic design is the conjugated backbone of the molecule, which simultaneously provides the potential landscape of the rotor orientation and a real-time measure of that orientation through the modulation of the conductivity. Using quantum chemistry calculations, we show that this approach provides full control over the speed and continuity of motion, thereby combining electrical and mechanical control at the molecular level over a wide range of temperatures. Moreover, chemistry can be used to change all key parameters of the device, enabling a variety of new experiments on molecular motors.

High molecular weight DNA assembly in vivo for synthetic biology applications.

Science.gov (United States)

Juhas, Mario; Ajioka, James W

2017-05-01

DNA assembly is the key technology of the emerging interdisciplinary field of synthetic biology. While the assembly of smaller DNA fragments is usually performed in vitro, high molecular weight DNA molecules are assembled in vivo via homologous recombination in the host cell. Escherichia coli, Bacillus subtilis and Saccharomyces cerevisiae are the main hosts used for DNA assembly in vivo. Progress in DNA assembly over the last few years has paved the way for the construction of whole genomes. This review provides an update on recent synthetic biology advances with particular emphasis on high molecular weight DNA assembly in vivo in E. coli, B. subtilis and S. cerevisiae. Special attention is paid to the assembly of whole genomes, such as those of the first synthetic cell, synthetic yeast and minimal genomes.

[Molecular biology, darwinism and nomogenesis].

Science.gov (United States)

Vol'kenshteĭn, M V

1987-01-01

The theory of nomogenesis put forward by L. S. Berg in 1922 is discussed. It is shown that side by side with some erroneous anti-darwinian ideas the theory contains a series of important suggestions which anticipate the further development of the synthetic theory of evolution. Berg has foreseen the development of molecular biology. Thus he was the fore-teller of our branch of science. The theory of nomogenesis emphasized the limitations of natural selection which determine the directionality of evolution. Berg treated the speciation as a kind of phase transition. Even the most conscientious critics of Berg have misrepresented the real sense of his works. It is totally groundless to treat nomogenesis as an idealistic of Lamarkian theory. Berg was superior to his critics. However the enthusiasm about nomogenesis in our time shows the inability to separate "the grains from weeds".

molecular biology approach to the search for novel hiv proteases ...

African Journals Online (AJOL)

... which could be tested in the animal models of HIV infection before subjection to clinical trials. Optimistically, the magic HIV therapeutics may be hidden in such insects and may require the application of molecular biology techniques to unravel. KEY WORDS: Antiretroviral drugs, malaria, proteases, restriction enzymes, ...

The emergence of sarcomeric, graded-polarity and spindle-like patterns in bundles of short cytoskeletal polymers and two opposite molecular motors

International Nuclear Information System (INIS)

Craig, E M; Dey, S; Mogilner, A

2011-01-01

We use linear stability analysis and numerical solutions of partial differential equations to investigate pattern formation in the one-dimensional system of short dynamic polymers and one (plus-end directed) or two (one is plus-end, another minus-end directed) molecular motors. If polymer sliding and motor gliding rates are slow and/or the polymer turnover rate is fast, then the polymer-motor bundle has mixed polarity and homogeneous motor distribution. However, if motor gliding is fast, a sarcomeric pattern with periodic bands of alternating polymer polarity separated by motor aggregates evolves. On the other hand, if polymer sliding is fast, a graded-polarity bundle with motors at the center emerges. In the presence of the second, minus-end directed motor, the sarcomeric pattern is more ubiquitous, while the graded-polarity pattern is destabilized. However, if the minus-end motor is weaker than the plus-end directed one, and/or polymer nucleation is autocatalytic, and/or long polymers are present in the bundle, then a spindle-like architecture with a sorted-out polarity emerges with the plus-end motors at the center and minus-end motors at the edges. We discuss modeling implications for actin-myosin fibers and in vitro and meiotic spindles.

Molecular biology of Homo sapiens: Abstracts of papers presented at the 51st Cold Spring Harbor symposium on quantitative biology

International Nuclear Information System (INIS)

Watson, J.D.; Siniscalco, M.

1986-01-01

This volume contains abstracts of papers presented at the 51st Cold Springs Harbor Symposium on Quantitative Biology. The topic for this meeting was the ''Molecular Biology of Homo sapiens.'' Sessions were entitled Human Gene Map, Human Cancer Genes, Genetic Diagnosis, Human Evolution, Drugs Made Off Human Genes, Receptors, and Gene Therapy. (DT)

Abstracts of the 27. Annual meeting of the Brazilian Society on Biochemistry and Molecular Biology

International Nuclear Information System (INIS)

1998-01-01

This meeting was about biochemistry and molecular biology. It was discussed topics related to bio energetic, channels, transports, biotechnology, metabolism, cellular biology, immunology, toxicology, photobiology and pharmacology

Abstracts of the 26. Annual meeting of the Brazilian Society on Biochemistry and Molecular Biology

International Nuclear Information System (INIS)

1997-01-01

This meeting was about biochemistry and molecular biology. It was discussed topics related to bio energetic, channels, transports, biotechnology, metabolism, cellular biology, immunology, toxicology, photobiology and pharmacology

A classical Master equation approach to modeling an artificial protein motor

International Nuclear Information System (INIS)

Kuwada, Nathan J.; Blab, Gerhard A.; Linke, Heiner

2010-01-01

Inspired by biomolecular motors, as well as by theoretical concepts for chemically driven nanomotors, there is significant interest in constructing artificial molecular motors. One driving force is the opportunity to create well-controlled model systems that are simple enough to be modeled in detail. A remaining challenge is the fact that such models need to take into account processes on many different time scales. Here we describe use of a classical Master equation approach, integrated with input from Langevin and molecular dynamics modeling, to stochastically model an existing artificial molecular motor concept, the Tumbleweed, across many time scales. This enables us to study how interdependencies between motor processes, such as center-of-mass diffusion and track binding/unbinding, affect motor performance. Results from our model help guide the experimental realization of the proposed motor, and potentially lead to insights that apply to a wider class of molecular motors.

Parallel computing and molecular dynamics of biological membranes

International Nuclear Information System (INIS)

La Penna, G.; Letardi, S.; Minicozzi, V.; Morante, S.; Rossi, G.C.; Salina, G.

1998-01-01

In this talk I discuss the general question of the portability of molecular dynamics codes for diffusive systems on parallel computers of the APE family. The intrinsic single precision of the today available platforms does not seem to affect the numerical accuracy of the simulations, while the absence of integer addressing from CPU to individual nodes puts strong constraints on possible programming strategies. Liquids can be satisfactorily simulated using the ''systolic'' method. For more complex systems, like the biological ones at which we are ultimately interested in, the ''domain decomposition'' approach is best suited to beat the quadratic growth of the inter-molecular computational time with the number of atoms of the system. The promising perspectives of using this strategy for extensive simulations of lipid bilayers are briefly reviewed. (orig.)

The molecular biology and diagnostics of Chlamydia trachomatis

DEFF Research Database (Denmark)

Birkelund, Svend

1992-01-01

The rapid development of biotechnological methods provides the potential of dissecting the molecular structure of microorganisms. In this review the molecular biology of chlamydia is described. The genus Chlamydia contains three species C. trachomatis, C. psittaci, and C. pneumonia which all...... are important human pathogens. Chlamydia is obligate intracellular bacteria with a unique biphasic life cycle. The extracellularly chlamydial elementary bodies (EB) are small, metabolic inactive, infectious particles with a tight outer cell membrane. After internalization into host cells the chlamydial...... of chlamydia have not yet been found. The adhesin(s) is unknown, and no factor of importance for the inhibition of fusion between phagosome and host cell lysosomes has been described. A protein similar to the mip gene product of Legionella pneumofila may be a possible candidate for a pathogenicity factor...

Combining Radiation Epidemiology With Molecular Biology-Changing From Health Risk Estimates to Therapeutic Intervention.

Science.gov (United States)

Abend, Michael; Port, Matthias

2016-08-01

The authors herein summarize six presentations dedicated to the key session "molecular radiation epidemiology" of the ConRad meeting 2015. These presentations were chosen in order to highlight the promise when combining conventional radiation epidemiology with molecular biology. Conventional radiation epidemiology uses dose estimates for risk predictions on health. However, combined with molecular biology, dose-dependent bioindicators of effect hold the promise to improve clinical diagnostics and to provide target molecules for potential therapeutic intervention. One out of the six presentations exemplified the use of radiation-induced molecular changes as biomarkers of exposure by measuring stabile chromosomal translocations. The remaining five presentations focused on molecular changes used as bioindicators of the effect. These bioindicators of the effect could be used for diagnostic purposes on colon cancers (genomic instability), thyroid cancer (CLIP2), or head and neck squamous cell cancers. Therapeutic implications of gene expression changes were examined in Chernobyl thyroid cancer victims and Mayak workers.

Molecular phenology in plants: in natura systems biology for the comprehensive understanding of seasonal responses under natural environments.

Science.gov (United States)

Kudoh, Hiroshi

2016-04-01

Phenology refers to the study of seasonal schedules of organisms. Molecular phenology is defined here as the study of the seasonal patterns of organisms captured by molecular biology techniques. The history of molecular phenology is reviewed briefly in relation to advances in the quantification technology of gene expression. High-resolution molecular phenology (HMP) data have enabled us to study phenology with an approach of in natura systems biology. I review recent analyses of FLOWERING LOCUS C (FLC), a temperature-responsive repressor of flowering, along the six steps in the typical flow of in natura systems biology. The extensive studies of the regulation of FLC have made this example a successful case in which a comprehensive understanding of gene functions has been progressing. The FLC-mediated long-term memory of past temperatures creates time lags with other seasonal signals, such as photoperiod and short-term temperature. Major signals that control flowering time have a phase lag between them under natural conditions, and hypothetical phase lag calendars are proposed as mechanisms of season detection in plants. Transcriptomic HMP brings a novel strategy to the study of molecular phenology, because it provides a comprehensive representation of plant functions. I discuss future perspectives of molecular phenology from the standpoints of molecular biology, evolutionary biology and ecology. © 2015 The Author. New Phytologist © 2015 New Phytologist Trust.

Haemoprotozoa: Making biological sense of molecular phylogenies

Directory of Open Access Journals (Sweden)

Peter O'Donoghue

2017-12-01

Full Text Available A range of protistan parasites occur in the blood of vertebrates and are transmitted by haematophagous invertebrate vectors. Some 48 genera are recognized in bood primarily on the basis of parasite morphology and host specificity; including extracellular kinetoplastids (trypanosomatids and intracellular apicomplexa (haemogregarines, haemococcidia, haemosporidia and piroplasms. Gene sequences are available for a growing number of species and molecular phylogenies often link parasite and host or vector evolution. This review endeavours to reconcile molecular clades with biological characters. Four major trypanosomatid clades have been associated with site of development in the vector: salivarian or stercorarian for Trypanosoma, and supra- or peri-pylorian for Leishmania. Four haemogregarine clades have been associated with acarine vectors (Hepatozoon A and B, Karyolysus, Hemolivia and another two with leeches (Dactylosoma, Haemogregarina sensu stricto. Two haemococcidian clades (Lankesterella, Schellackia using leeches and mosquitoes (as paratenic hosts! were paraphyletic with monoxenous enteric coccidia. Two major haemosporidian clades have been associated with mosquito vectors (Plasmodium from mammals, Plasmodium from birds and lizards, two with midges (Hepatocystis from bats, Parahaemoproteus from birds and two with louse-flies and black-flies (Haemoproteus and Leucocytozoon from birds. Three major piroplasm clades were recognized: one associated with transovarian transmission in ticks (Babesia sensu stricto; one with pre-erythrocytic schizogony in vertebrates (Theileria/Cytauxzoon; and one with neither (Babesia sensu lato. Broad comparative studies with allied groups suggest that trypanosomatids and haemogregarines evolved first in aquatic and then terrestrial environments, as evidenced by extant lineages in invertebrates and their radiation in vertebrates. In contrast, haemosporidia and haemococcidia are thought to have evolved first in

A Model of How Different Biology Experts Explain Molecular and Cellular Mechanisms

Science.gov (United States)

Trujillo, Caleb M.; Anderson, Trevor R.; Pelaez, Nancy J.

2015-01-01

Constructing explanations is an essential skill for all science learners. The goal of this project was to model the key components of expert explanation of molecular and cellular mechanisms. As such, we asked: What is an appropriate model of the components of explanation used by biology experts to explain molecular and cellular mechanisms? Do explanations made by experts from different biology subdisciplines at a university support the validity of this model? Guided by the modeling framework of R. S. Justi and J. K. Gilbert, the validity of an initial model was tested by asking seven biologists to explain a molecular mechanism of their choice. Data were collected from interviews, artifacts, and drawings, and then subjected to thematic analysis. We found that biologists explained the specific activities and organization of entities of the mechanism. In addition, they contextualized explanations according to their biological and social significance; integrated explanations with methods, instruments, and measurements; and used analogies and narrated stories. The derived methods, analogies, context, and how themes informed the development of our final MACH model of mechanistic explanations. Future research will test the potential of the MACH model as a guiding framework for instruction to enhance the quality of student explanations. PMID:25999313

Conservation Biological Control of Pests in the Molecular Era: New Opportunities to Address Old Constraints

Science.gov (United States)

Gurr, Geoff M.; You, Minsheng

2016-01-01

Biological control has long been considered a potential alternative to pesticidal strategies for pest management but its impact and level of use globally remain modest and inconsistent. A rapidly expanding range of molecular – particularly DNA-related – techniques is currently revolutionizing many life sciences. This review identifies a series of constraints on the development and uptake of conservation biological control and considers the contemporary and likely future influence of molecular methods on these constraints. Molecular approaches are now often used to complement morphological taxonomic methods for the identification and study of biological control agents including microbes. A succession of molecular techniques has been applied to ‘who eats whom’ questions in food-web ecology. Polymerase chain reaction (PCR) approaches have largely superseded immunological approaches such as enzyme-linked immunosorbent assay (ELISA) and now – in turn – are being overtaken by next generation sequencing (NGS)-based approaches that offer unparalleled power at a rapidly diminishing cost. There is scope also to use molecular techniques to manipulate biological control agents, which will be accelerated with the advent of gene editing tools, the CRISPR/Cas9 system in particular. Gene editing tools also offer unparalleled power to both elucidate and manipulate plant defense mechanisms including those that involve natural enemy attraction to attacked plants. Rapid advances in technology will allow the development of still more novel pest management options for which uptake is likely to be limited chiefly by regulatory hurdles. PMID:26793225

Molecular biology of Homo sapiens: Abstracts of papers presented at the 51st Cold Spring Harbor symposium on quantitative biology

Energy Technology Data Exchange (ETDEWEB)

Watson, J.D.; Siniscalco, M.

1986-01-01

This volume contains abstracts of papers presented at the 51st Cold Springs Harbor Symposium on Quantitative Biology. The topic for this meeting was the ''Molecular Biology of Homo sapiens.'' Sessions were entitled Human Gene Map, Human Cancer Genes, Genetic Diagnosis, Human Evolution, Drugs Made Off Human Genes, Receptors, and Gene Therapy. (DT)

Studies of viral DNA packaging motors with optical tweezers: a comparison of motor function in bacteriophages φ29, λ, and T4

Science.gov (United States)

Smith, Douglas E.; Fuller, Derek N.; Raymer, Dorian M.; Rickgauer, Peter; Grimes, Shelley; Jardine, Paul J.; Anderson, Dwight L.; Catalano, Carlos E.; Kottadiel, Vishal; Rao, Venigalla B.

2007-09-01

A key step in the assembly of many viruses is the packaging of double-stranded DNA into a viral procapsid (an empty protein shell) by the action of an ATP-powered portal motor complex. We have developed methods to measure the packaging of single DNA molecules into single viral proheads in real time using optical tweezers. We can measure DNA binding and initiation of translocation, the DNA translocation dynamics, and the filling of the capsid against resisting forces. In addition to studying bacteriophage φ29, we have recently extended these methods to study the E. coli bacteriophages λ and T4, two important model systems in molecular biology. The three systems have different capsid sizes/shapes, genome lengths, and biochemical and structural differences in their packaging motors. Here, we compare and contrast these three systems. We find that all three motors translocate DNA processively and generate very large forces, each exceeding 50 piconewtons, ~20x higher force than generated by the skeletal muscle myosin 2 motor. This high force generation is required to overcome the forces resisting the confinement of the stiff, highly charged DNA at high density within the viral capsids. However, there are also striking differences between the three motors: they exhibit different DNA translocation rates, degrees of static and dynamic disorder, responses to load, and pausing and slipping dynamics.

Carbon Nanotube Based Molecular Electronics and Motors: A View from Classical and Quantum Dynamics Simulations

Science.gov (United States)

Srivastava, Deepak; Saini, Subhash (Technical Monitor)

1998-01-01

The tubular forms of fullerenes popularly known as carbon nanotubes are experimentally produced as single-, multiwall, and rope configurations. The nanotubes and nanoropes have shown to exhibit unusual mechanical and electronic properties. The single wall nanotubes exhibit both semiconducting and metallic behavior. In short undefected lengths they are the known strongest fibers which are unbreakable even when bent in half. Grown in ropes their tensile strength is approximately 100 times greater than steel at only one sixth the weight. Employing large scale classical and quantum molecular dynamics simulations we will explore the use of carbon nanotubes and carbon nanotube junctions in 2-, 3-, and 4-point molecular electronic device components, dynamic strength characterization for compressive, bending and torsional strains, and chemical functionalization for possible use in a nanoscale molecular motor. The above is an unclassified material produced for non-competitive basic research in the nanotechnology area.

Markov process of muscle motors

International Nuclear Information System (INIS)

Kondratiev, Yu; Pechersky, E; Pirogov, S

2008-01-01

We study a Markov random process describing muscle molecular motor behaviour. Every motor is either bound up with a thin filament or unbound. In the bound state the motor creates a force proportional to its displacement from the neutral position. In both states the motor spends an exponential time depending on the state. The thin filament moves at a velocity proportional to the average of all displacements of all motors. We assume that the time which a motor stays in the bound state does not depend on its displacement. Then one can find an exact solution of a nonlinear equation appearing in the limit of an infinite number of motors

Mapping molecular orientational distributions for biological sample in 3D (Conference Presentation)

Science.gov (United States)

HE, Wei; Ferrand, Patrick; Richter, Benjamin; Bastmeyer, Martin; Brasselet, Sophie

2016-04-01

Measuring molecular orientation properties is very appealing for scientists in molecular and cell biology, as well as biomedical research. Orientational organization at the molecular scale is indeed an important brick to cells and tissues morphology, mechanics, functions and pathologies. Recent work has shown that polarized fluorescence imaging, based on excitation polarization tuning in the sample plane, is able to probe molecular orientational order in biological samples; however this applies only to information in 2D, projected in the sample plane. To surpass this limitation, we extended this approach to excitation polarization tuning in 3D. The principle is based on the decomposition of any arbitrary 3D linear excitation in a polarization along the longitudinal z-axis, and a polarization in the transverse xy-sample plane. We designed an interferometer with one arm generating radial polarization light (thus producing longitudinal polarization under high numerical aperture focusing), the other arm controlling a linear polarization in the transverse plane. The amplitude ratio between the two arms can vary so as to get any linear polarized excitation in 3D at the focus of a high NA objective. This technique has been characterized by polarimetry imaging at the back focal plane of the focusing objective, and modeled theoretically. 3D polarized fluorescence microscopy is demonstrated on actin stress fibers in non-flat cells suspended on synthetic polymer structures forming supporting pillars, for which heterogeneous actin orientational order could be identified. This technique shows a great potential in structural investigations in 3D biological systems, such as cell spheroids and tissues.

Stochastic processes in cell biology

CERN Document Server

Bressloff, Paul C

2014-01-01

This book develops the theory of continuous and discrete stochastic processes within the context of cell biology.  A wide range of biological topics are covered including normal and anomalous diffusion in complex cellular environments, stochastic ion channels and excitable systems, stochastic calcium signaling, molecular motors, intracellular transport, signal transduction, bacterial chemotaxis, robustness in gene networks, genetic switches and oscillators, cell polarization, polymerization, cellular length control, and branching processes. The book also provides a pedagogical introduction to the theory of stochastic process – Fokker Planck equations, stochastic differential equations, master equations and jump Markov processes, diffusion approximations and the system size expansion, first passage time problems, stochastic hybrid systems, reaction-diffusion equations, exclusion processes, WKB methods, martingales and branching processes, stochastic calculus, and numerical methods.   This text is primarily...

Doctoral conceptual thresholds in cellular and molecular biology

Science.gov (United States)

Feldon, David F.; Rates, Christopher; Sun, Chongning

2017-12-01

In the biological sciences, very little is known about the mechanisms by which doctoral students acquire the skills they need to become independent scientists. In the postsecondary biology education literature, identification of specific skills and effective methods for helping students to acquire them are limited to undergraduate education. To establish a foundation from which to investigate the developmental trajectory of biologists' research skills, it is necessary to identify those skills which are integral to doctoral study and distinct from skills acquired earlier in students' educational pathways. In this context, the current study engages the framework of threshold concepts to identify candidate skills that are both obstacles and significant opportunities for developing proficiency in conducting research. Such threshold concepts are typically characterised as transformative, integrative, irreversible, and challenging. The results from interviews and focus groups with current and former doctoral students in cellular and molecular biology suggest two such threshold concepts relevant to their subfield: the first is an ability to effectively engage primary research literature from the biological sciences in a way that is critical without dismissing the value of its contributions. The second is the ability to conceptualise appropriate control conditions necessary to design and interpret the results of experiments in an efficient and effective manner for research in the biological sciences as a discipline. Implications for prioritising and sequencing graduate training experiences are discussed on the basis of the identified thresholds.

Molecular biology in marine science: Scientific questions, technological approaches, and practical implications

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-12-31

This report describes molecular techniques that could be invaluable in addressing process-oriented problems in the ocean sciences that have perplexed oceanographers for decades, such as understanding the basis for biogeochemical processes, recruitment processes, upper-ocean dynamics, biological impacts of global warming, and ecological impacts of human activities. The coupling of highly sophisticated methods, such as satellite remote sensing, which permits synoptic monitoring of chemical, physical, and biological parameters over large areas, with the power of modern molecular tools for ``ground truthing`` at small scales could allow scientists to address questions about marine organisms and the ocean in which they live that could not be answered previously. Clearly, the marine sciences are on the threshold of an exciting new frontier of scientific discovery and economic opportunity.

PathSys: integrating molecular interaction graphs for systems biology

Directory of Open Access Journals (Sweden)

Raval Alpan

2006-02-01

Full Text Available Abstract Background The goal of information integration in systems biology is to combine information from a number of databases and data sets, which are obtained from both high and low throughput experiments, under one data management scheme such that the cumulative information provides greater biological insight than is possible with individual information sources considered separately. Results Here we present PathSys, a graph-based system for creating a combined database of networks of interaction for generating integrated view of biological mechanisms. We used PathSys to integrate over 14 curated and publicly contributed data sources for the budding yeast (S. cerevisiae and Gene Ontology. A number of exploratory questions were formulated as a combination of relational and graph-based queries to the integrated database. Thus, PathSys is a general-purpose, scalable, graph-data warehouse of biological information, complete with a graph manipulation and a query language, a storage mechanism and a generic data-importing mechanism through schema-mapping. Conclusion Results from several test studies demonstrate the effectiveness of the approach in retrieving biologically interesting relations between genes and proteins, the networks connecting them, and of the utility of PathSys as a scalable graph-based warehouse for interaction-network integration and a hypothesis generator system. The PathSys's client software, named BiologicalNetworks, developed for navigation and analyses of molecular networks, is available as a Java Web Start application at http://brak.sdsc.edu/pub/BiologicalNetworks.

Günter Blobel: Pioneer of molecular cell biology (1936-2018).

Science.gov (United States)

2018-04-02

Günter Blobel was a scientific colossus who dedicated his career to understanding the mechanisms for protein sorting to membrane organelles. His monumental contributions established research paradigms for major arenas of molecular cell biology. For this work, he received many accolades, including the Nobel Prize in Medicine or Physiology in 1999. He was a scientist of extreme passion and a nurturing mentor for generations of researchers, imbuing them with his deep love of cell biology and galvanizing them to continue his scientific legacy. Günter passed away on February 18, 2018, at the age of 81. © 2018 Rockefeller University Press.

Biological Physics : Poincaré seminar

CERN Document Server

Bio-physique : séminaire Poincaré

2011-01-01

This new volume in the Poincaré Seminar Series, describing recent developments at the interface between physics and biology, is directed towards a broad audience of physicists, biologists, and mathematicians. Both the theoretical and experimental aspects are covered, and particular care is devoted to the pedagogical nature of the presentations. The first survey article, by Jean-Francois Joanny and Jacques Prost, describes the theoretical advances made in the study of "active gels", with applications to liquid crystals and cell motility. Jasper van der Gucht and Cécile Sykes then report on recent advances made with biomimetic model systems in the understanding of cytokinesis. The next article, by Jonathon Howard, presents several molecular models for motor proteins, which are compared with experimental results for kinesin. David Lacoste and Kirone Mallick then show theoretically that similar ratchet models of motor proteins naturally satisfy a fundamental time-reversal symmetry, the Gallavotti-Cohen fluctuat...

Towards a molecular understanding of the apicomplexan actin motor: on a road to novel targets for malaria remedies?

Energy Technology Data Exchange (ETDEWEB)

Kumpula, Esa-Pekka [University of Oulu, PO Box 3000, 90014 Oulu (Finland); Helmholtz Centre for Infection Research, Notkestrasse 85, 22607 Hamburg (Germany); German Electron Synchrotron, Notkestrasse 85, 22607 Hamburg (Germany); Kursula, Inari, E-mail: inari.kursula@helmholtz-hzi.de [University of Oulu, PO Box 3000, 90014 Oulu (Finland); Helmholtz Centre for Infection Research, Notkestrasse 85, 22607 Hamburg (Germany); German Electron Synchrotron, Notkestrasse 85, 22607 Hamburg (Germany); University of Bergen, Jonas Lies vei 91, 5009 Bergen (Norway)

2015-04-16

In this review, current structural understanding of the apicomplexan glideosome and actin regulation is described. Apicomplexan parasites are the causative agents of notorious human and animal diseases that give rise to considerable human suffering and economic losses worldwide. The most prominent parasites of this phylum are the malaria-causing Plasmodium species, which are widespread in tropical and subtropical regions, and Toxoplasma gondii, which infects one third of the world’s population. These parasites share a common form of gliding motility which relies on an actin–myosin motor. The components of this motor and the actin-regulatory proteins in Apicomplexa have unique features compared with all other eukaryotes. This, together with the crucial roles of these proteins, makes them attractive targets for structure-based drug design. In recent years, several structures of glideosome components, in particular of actins and actin regulators from apicomplexan parasites, have been determined, which will hopefully soon allow the creation of a complete molecular picture of the parasite actin–myosin motor and its regulatory machinery. Here, current knowledge of the function of this motor is reviewed from a structural perspective.

Dynamics and Thermodynamics of Molecular Machines

DEFF Research Database (Denmark)

Golubeva, Natalia

2014-01-01

to their microscopic size, molecular motors are governed by principles fundamentally different from those describing the operation of man-made motors such as car engines. In this dissertation the dynamic and thermodynamic properties of molecular machines are studied using the tools of nonequilibrium statistical......Molecular machines, or molecular motors, are small biophysical devices that perform a variety of essential metabolic processes such as DNA replication, protein synthesis and intracellular transport. Typically, these machines operate by converting chemical energy into motion and mechanical work. Due...... mechanics. The first part focuses on noninteracting molecular machines described by a paradigmatic continuum model with the aim of comparing and contrasting such a description to the one offered by the widely used discrete models. Many molecular motors, for example, kinesin involved in cellular cargo...

Massively Parallel, Molecular Analysis Platform Developed Using a CMOS Integrated Circuit With Biological Nanopores

Science.gov (United States)

Roever, Stefan

2012-01-01

A massively parallel, low cost molecular analysis platform will dramatically change the nature of protein, molecular and genomics research, DNA sequencing, and ultimately, molecular diagnostics. An integrated circuit (IC) with 264 sensors was fabricated using standard CMOS semiconductor processing technology. Each of these sensors is individually controlled with precision analog circuitry and is capable of single molecule measurements. Under electronic and software control, the IC was used to demonstrate the feasibility of creating and detecting lipid bilayers and biological nanopores using wild type α-hemolysin. The ability to dynamically create bilayers over each of the sensors will greatly accelerate pore development and pore mutation analysis. In addition, the noise performance of the IC was measured to be 30fA(rms). With this noise performance, single base detection of DNA was demonstrated using α-hemolysin. The data shows that a single molecule, electrical detection platform using biological nanopores can be operationalized and can ultimately scale to millions of sensors. Such a massively parallel platform will revolutionize molecular analysis and will completely change the field of molecular diagnostics in the future.

Introducing Molecular Biology to Environmental Engineers through Development of a New Course.

Science.gov (United States)

Oerther, Daniel B.

2002-01-01

Introduces a molecular biology course designed for environmental engineering majors using 16S ribosomal ribonucleic acid-targeted technology that allows students to identify and study microorganisms in bioreactor environments. (Contains 17 references.) (YDS)

How to measure load-dependent kinetics of individual motor molecules without a force clamp

DEFF Research Database (Denmark)

Sung, J.; Mortensen, Kim; Spudich, J.A.

2017-01-01

Single-molecule force spectroscopy techniques, including optical trapping, magnetic trapping, and atomic force microscopy, have provided unprecedented opportunities to understand biological processes at the smallest biological length scales. For example, they have been used to elucidate the molec......Single-molecule force spectroscopy techniques, including optical trapping, magnetic trapping, and atomic force microscopy, have provided unprecedented opportunities to understand biological processes at the smallest biological length scales. For example, they have been used to elucidate...... functions at the single molecule level, such as conformational changes and force-generation of individual motor proteins or force-dependent kinetics in molecular interactions. Here, we describe a new method, “Harmonic Force Spectroscopy (HFS).” With a conventional dual-beam optical trap and a simple...... concepts, experimental setup, step-by-step experimental protocol, theory, data analysis, and results....

2010 Plant Molecular Biology Gordon Research Conference

Energy Technology Data Exchange (ETDEWEB)

Michael Sussman

2010-07-23

The Plant Molecular Biology Conference has traditionally covered a breadth of exciting topics and the 2010 conference will continue in that tradition. Emerging concerns about food security have inspired a program with three main themes: (1) genomics, natural variation and breeding to understand adaptation and crop improvement, (2) hormonal cross talk, and (3) plant/microbe interactions. There are also sessions on epigenetics and proteomics/metabolomics. Thus this conference will bring together a range of disciplines, will foster the exchange of ideas and enable participants to learn of the latest developments and ideas in diverse areas of plant biology. The conference provides an excellent opportunity for individuals to discuss their research because additional speakers in each session will be selected from submitted abstracts. There will also be a poster session each day for a two-hour period prior to dinner. In particular, this conference plays a key role in enabling students and postdocs (the next generation of research leaders) to mingle with pioneers in multiple areas of plant science.

Abstracts of the 30. Annual meeting of the Brazilian Society on Biochemistry and Molecular Biology

International Nuclear Information System (INIS)

2001-01-01

Several aspects concerning biochemistry and molecular biology of either animals, plants and microorganisms are studied. Topics such as cell membrane structures (including receptors), enzymatic assays, biological pathways, structural chemical analysis, metabolism, biological functions are focused. The use of radiolabelled compounds (radioassay, radioreceptor assay) and nuclear magnetic resonance are the most applied techniques

Semester-Long Inquiry-Based Molecular Biology Laboratory: Transcriptional Regulation in Yeast

Science.gov (United States)

Oelkers, Peter M.

2017-01-01

A single semester molecular biology laboratory has been developed in which students design and execute a project examining transcriptional regulation in "Saccharomyces cerevisiae." Three weeks of planning are allocated to developing a hypothesis through literature searches and use of bioinformatics. Common experimental plans address a…

Molecular structure descriptors in the computer-aided design of biologically active compounds

International Nuclear Information System (INIS)

Raevsky, Oleg A

1999-01-01

The current state of description of molecular structure in computer-aided molecular design of biologically active compounds by means of descriptors is analysed. The information contents of descriptors increases in the following sequence: element-level descriptors-structural formulae descriptors-electronic structure descriptors-molecular shape descriptors-intermolecular interaction descriptors. Each subsequent class of descriptors normally covers information contained in the previous-level ones. It is emphasised that it is practically impossible to describe all the features of a molecular structure in terms of any single class of descriptors. It is recommended to optimise the number of descriptors used by means of appropriate statistical procedures and characteristics of structure-property models based on these descriptors. The bibliography includes 371 references.

Synthetic biology and molecular genetics in non-conventional yeasts: Current tools and future advances.

Science.gov (United States)

Wagner, James M; Alper, Hal S

2016-04-01

Coupling the tools of synthetic biology with traditional molecular genetic techniques can enable the rapid prototyping and optimization of yeast strains. While the era of yeast synthetic biology began in the well-characterized model organism Saccharomyces cerevisiae, it is swiftly expanding to include non-conventional yeast production systems such as Hansenula polymorpha, Kluyveromyces lactis, Pichia pastoris, and Yarrowia lipolytica. These yeasts already have roles in the manufacture of vaccines, therapeutic proteins, food additives, and biorenewable chemicals, but recent synthetic biology advances have the potential to greatly expand and diversify their impact on biotechnology. In this review, we summarize the development of synthetic biological tools (including promoters and terminators) and enabling molecular genetics approaches that have been applied in these four promising alternative biomanufacturing platforms. An emphasis is placed on synthetic parts and genome editing tools. Finally, we discuss examples of synthetic tools developed in other organisms that can be adapted or optimized for these hosts in the near future. Copyright © 2015 Elsevier Inc. All rights reserved.

Abstracts of the 28. Annual meeting of the Brazilian Society on Biochemistry and Molecular Biology

International Nuclear Information System (INIS)

1999-01-01

Biochemistry, genetic and molecular biology aspects of either animals (including man), plants and microorganisms are studied. Topics such as cell membrane structures (including receptors), enzymatic assays, biological pathways, structural chemical analysis, metabolism, biological functions are focused. The use of radiolabelled compounds (radioassay, radioenzymatic assay, radioreceptor assay) and nuclear magnetic resonance are the most applied techniques

A Self-Assisting Protein Folding Model for Teaching Structural Molecular Biology.

Science.gov (United States)

Davenport, Jodi; Pique, Michael; Getzoff, Elizabeth; Huntoon, Jon; Gardner, Adam; Olson, Arthur

2017-04-04

Structural molecular biology is now becoming part of high school science curriculum thus posing a challenge for teachers who need to convey three-dimensional (3D) structures with conventional text and pictures. In many cases even interactive computer graphics does not go far enough to address these challenges. We have developed a flexible model of the polypeptide backbone using 3D printing technology. With this model we have produced a polypeptide assembly kit to create an idealized model of the Triosephosphate isomerase mutase enzyme (TIM), which forms a structure known as TIM barrel. This kit has been used in a laboratory practical where students perform a step-by-step investigation into the nature of protein folding, starting with the handedness of amino acids to the formation of secondary and tertiary structure. Based on the classroom evidence we collected, we conclude that these models are valuable and inexpensive resource for teaching structural molecular biology. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Role of Molecular Biology in the Biomonitoring of Human Exposure to Chemicals

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Balam Muñoz

2010-11-01

Full Text Available Exposure to different substances in an occupational environment is of utmost concern to global agencies such as the World Health Organization and the International Labour Organization. Interest in improving work health conditions, particularly of those employees exposed to noxious chemicals, has increased considerably and has stimulated the search for new, more specific and selective tests. Recently, the field of molecular biology has been indicated as an alternative technique for monitoring personnel while evaluating work-related pathologies. Originally, occupational exposure to environmental toxicants was assessed using biochemical techniques to determine the presence of higher concentrations of toxic compounds in blood, urine, or other fluids or tissues; results were used to evaluate potential health risk. However, this approach only estimates the presence of a noxious chemical and its effects, but does not prevent or diminish the risk. Molecular biology methods have become very useful in occupational medicine to provide more accurate and opportune diagnostics. In this review, we discuss the role of the following common techniques: (1 Use of cell cultures; (2 evaluation of gene expression; (3 the “omic” sciences (genomics, transcriptomics, proteomics and metabolomics and (4 bioinformatics. We suggest that molecular biology has many applications in occupational health where the data can be applied to general environmental conditions.

Building bridges between cellular and molecular structural biology.

Science.gov (United States)

Patwardhan, Ardan; Brandt, Robert; Butcher, Sarah J; Collinson, Lucy; Gault, David; Grünewald, Kay; Hecksel, Corey; Huiskonen, Juha T; Iudin, Andrii; Jones, Martin L; Korir, Paul K; Koster, Abraham J; Lagerstedt, Ingvar; Lawson, Catherine L; Mastronarde, David; McCormick, Matthew; Parkinson, Helen; Rosenthal, Peter B; Saalfeld, Stephan; Saibil, Helen R; Sarntivijai, Sirarat; Solanes Valero, Irene; Subramaniam, Sriram; Swedlow, Jason R; Tudose, Ilinca; Winn, Martyn; Kleywegt, Gerard J

2017-07-06

The integration of cellular and molecular structural data is key to understanding the function of macromolecular assemblies and complexes in their in vivo context. Here we report on the outcomes of a workshop that discussed how to integrate structural data from a range of public archives. The workshop identified two main priorities: the development of tools and file formats to support segmentation (that is, the decomposition of a three-dimensional volume into regions that can be associated with defined objects), and the development of tools to support the annotation of biological structures.

Molecular biological features of male germ cell differentiation

Science.gov (United States)

HIROSE, MIKA; TOKUHIRO, KEIZO; TAINAKA, HITOSHI; MIYAGAWA, YASUSHI; TSUJIMURA, AKIRA; OKUYAMA, AKIHIKO; NISHIMUNE, YOSHITAKE

2007-01-01

Somatic cell differentiation is required throughout the life of a multicellular organism to maintain homeostasis. In contrast, germ cells have only one specific function; to preserve the species by conveying the parental genes to the next generation. Recent studies of the development and molecular biology of the male germ cell have identified many genes, or isoforms, that are specifically expressed in the male germ cell. In the present review, we consider the unique features of male germ cell differentiation. (Reprod Med Biol 2007; 6: 1–9) PMID:29699260

Abstracts of the 29. annual meeting of the Brazilian Society on Biochemistry and Molecular Biology

International Nuclear Information System (INIS)

2000-01-01

Several aspects concerning biochemistry and molecular biology of either animals (including man), plants and microorganisms are studied. Topics such as cell membrane structures (including receptors), enzymatic assays, biological pathways, structural chemical analysis, metabolism, biological functions are focused. The use of radiolabelled compounds (radioassay, radioenzymatic assay, radioreceptor assay and nuclear magnetic resonance are the most applied techniques

Correlativity study on MRI morphologic features, pathology, and molecular biology of breast cancer

International Nuclear Information System (INIS)

Chen Rong; Gong Shuigen; Zhang Weiguo; Chen Jinhua; He Shuangwu; Liu Baohua; Li Zengpeng

2004-01-01

Objective: To investigate the correlation among MRI morphologic features, pathology, and molecular biology of breast cancer. Methods: MR scanning was performed in 78 patients with breast cancer before operation and MRI morphologic features of breast cancer were analyzed. The mastectomy specimens of the breast neoplasm were stained with immunohistochemistry, and the expression of estrogen receptor (ER), progesterone receptor (PR), C-erbB-2, p53, and the distribution of microvessel density (MVD) was measured. The pathologic results were compared with MRI features. Results: Among the 80 breast cancers, ER positive expression was positively correlated with the spiculate margin of breast cancer (P 0.05). Among the 41 breast cancers with dynamic MR scans, there was positive correlation between the spatial distribution of contrast agent and MVD (P<0.01). Conclusion: There exists some correlation among MRI morphologic features, pathology, and molecular biology factors in breast cancer to certain extent. The biologic behavior and prognosis of the breast cancer can be assessed according to MRI features

The Physics of Proteins An Introduction to Biological Physics and Molecular Biophysics

CERN Document Server

Frauenfelder, Hans; Chan, Winnie S

2010-01-01

Physics and the life sciences have established new connections within the past few decades, resulting in biological physics as an established subfield with strong groups working in many physics departments. These interactions between physics and biology form a two-way street with physics providing new tools and concepts for understanding life, while biological systems can yield new insights into the physics of complex systems. To address the challenges of this interdisciplinary area, The Physics of Proteins: An Introduction to Biological Physics and Molecular Biophysics is divided into three interconnected sections. In Parts I and II, early chapters introduce the terminology and describe the main biological systems that physicists will encounter. Similarities between biomolecules, glasses, and solids are stressed with an emphasis on the fundamental concepts of living systems. The central section (Parts III and IV) delves into the dynamics of complex systems. A main theme is the realization that biological sys...

Towards building hybrid biological/in silico neural networks for motor neuroprosthetic control

Directory of Open Access Journals (Sweden)

Mehmet eKocaturk

2015-08-01

Full Text Available In this article, we introduce the Bioinspired Neuroprosthetic Design Environment (BNDE as a practical platform for the development of novel brain machine interface (BMI controllers which are based on spiking model neurons. We built the BNDE around a hard real-time system so that it is capable of creating simulated synapses from extracellularly recorded neurons to model neurons. In order to evaluate the practicality of the BNDE for neuroprosthetic control experiments, a novel, adaptive BMI controller was developed and tested using real-time closed-loop simulations. The present controller consists of two in silico medium spiny neurons which receive simulated synaptic inputs from recorded motor cortical neurons. In the closed-loop simulations, the recordings from the cortical neurons were imitated using an external, hardware-based neural signal synthesizer. By implementing a reward-modulated spike timing-dependent plasticity rule, the controller achieved perfect target reach accuracy for a two target reaching task in one dimensional space. The BNDE combines the flexibility of software-based spiking neural network (SNN simulations with powerful online data visualization tools and is a low-cost, PC-based and all-in-one solution for developing neurally-inspired BMI controllers. We believe the BNDE is the first implementation which is capable of creating hybrid biological/in silico neural networks for motor neuroprosthetic control and utilizes multiple CPU cores for computationally intensive real-time SNN simulations.

Adrenocortical carcinoma: the dawn of a new era of genomic and molecular biology analysis.

Science.gov (United States)

Armignacco, R; Cantini, G; Canu, L; Poli, G; Ercolino, T; Mannelli, M; Luconi, M

2018-05-01

Over the last decade, the development of novel and high penetrance genomic approaches to analyze biological samples has provided very new insights in the comprehension of the molecular biology and genetics of tumors. The use of these techniques, consisting of exome sequencing, transcriptome, miRNome, chromosome alteration, genome, and epigenome analysis, has also been successfully applied to adrenocortical carcinoma (ACC). In fact, the analysis of large cohorts of patients allowed the stratification of ACC with different patterns of molecular alterations, associated with different outcomes, thus providing a novel molecular classification of the malignancy to be associated with the classical pathological analysis. Improving our knowledge about ACC molecular features will result not only in a better diagnostic and prognostic accuracy, but also in the identification of more specific therapeutic targets for the development of more effective pharmacological anti-cancer approaches. In particular, the specific molecular alteration profiles identified in ACC may represent targetable events by the use of already developed or newly designed drugs enabling a better and more efficacious management of the ACC patient in the context of new frontiers of personalized precision medicine.

New approaches in mathematical biology: Information theory and molecular machines

International Nuclear Information System (INIS)

Schneider, T.

1995-01-01

My research uses classical information theory to study genetic systems. Information theory was founded by Claude Shannon in the 1940's and has had an enormous impact on communications engineering and computer sciences. Shannon found a way to measure information. This measure can be used to precisely characterize the sequence conservation at nucleic-acid binding sites. The resulting methods, by completely replacing the use of ''consensus sequences'', provide better models for molecular biologists. An excess of conservation led us to do experimental work on bacteriophage T7 promoters and the F plasmid IncD repeats. The wonderful fidelity of telephone communications and compact disk (CD) music can be traced directly to Shannon's channel capacity theorem. When rederived for molecular biology, this theorem explains the surprising precision of many molecular events. Through connections with the Second Law of Thermodyanmics and Maxwell's Demon, this approach also has implications for the development of technology at the molecular level. Discussions of these topics are held on the internet news group bionet.info-theo. (author). (Abstract only)

Recent advances in biological effect and molecular mechanism of arabidopsis thaliana irradiated by ion beams

International Nuclear Information System (INIS)

Wu Dali; Hou Suiwen; Li Wenjian

2008-01-01

Newly research progresses were summarized in effect of ion beams on seed surface, biological effect, growth, development, gravitropism and so on. Furthermore, mutation molecular mechanism of Arabidopsis thaliana was discussed, for example, alteration of DNA bases, DNA damage, chromosomal recombination, characteristics of mutant transmissibility, etc. Meanwhile, the achievements of transfer- ring extraneous gene to Arabidopsis thaliana by ion beams were reviewed in the paper. At last, the future prospective are also discussed here in mutation molecular mechanism and the potential application of biological effect of heavy ion beams. (authors)

Research Applications of Proteolytic Enzymes in Molecular Biology

Directory of Open Access Journals (Sweden)

József Tőzsér

2013-11-01

Full Text Available Proteolytic enzymes (also termed peptidases, proteases and proteinases are capable of hydrolyzing peptide bonds in proteins. They can be found in all living organisms, from viruses to animals and humans. Proteolytic enzymes have great medical and pharmaceutical importance due to their key role in biological processes and in the life-cycle of many pathogens. Proteases are extensively applied enzymes in several sectors of industry and biotechnology, furthermore, numerous research applications require their use, including production of Klenow fragments, peptide synthesis, digestion of unwanted proteins during nucleic acid purification, cell culturing and tissue dissociation, preparation of recombinant antibody fragments for research, diagnostics and therapy, exploration of the structure-function relationships by structural studies, removal of affinity tags from fusion proteins in recombinant protein techniques, peptide sequencing and proteolytic digestion of proteins in proteomics. The aim of this paper is to review the molecular biological aspects of proteolytic enzymes and summarize their applications in the life sciences.

Features of Knowledge Building in Biology: Understanding Undergraduate Students' Ideas about Molecular Mechanisms.

Science.gov (United States)

Southard, Katelyn; Wince, Tyler; Meddleton, Shanice; Bolger, Molly S

2016-01-01

Research has suggested that teaching and learning in molecular and cellular biology (MCB) is difficult. We used a new lens to understand undergraduate reasoning about molecular mechanisms: the knowledge-integration approach to conceptual change. Knowledge integration is the dynamic process by which learners acquire new ideas, develop connections between ideas, and reorganize and restructure prior knowledge. Semistructured, clinical think-aloud interviews were conducted with introductory and upper-division MCB students. Interviews included a written conceptual assessment, a concept-mapping activity, and an opportunity to explain the biomechanisms of DNA replication, transcription, and translation. Student reasoning patterns were explored through mixed-method analyses. Results suggested that students must sort mechanistic entities into appropriate mental categories that reflect the nature of MCB mechanisms and that conflation between these categories is common. We also showed how connections between molecular mechanisms and their biological roles are part of building an integrated knowledge network as students develop expertise. We observed differences in the nature of connections between ideas related to different forms of reasoning. Finally, we provide a tentative model for MCB knowledge integration and suggest its implications for undergraduate learning. © 2016 K. Southard et al. CBE—Life Sciences Education © 2016 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Molecular gyroscopes and biological effects of weak extremely low-frequency magnetic fields

International Nuclear Information System (INIS)

Binhi, V.N.; Savin, A.V.

2002-01-01

Extremely low-frequency magnetic fields are known to affect biological systems. In many cases, biological effects display 'windows' in biologically effective parameters of the magnetic fields: most dramatic is the fact that the relatively intense magnetic fields sometimes do not cause appreciable effect, while smaller fields of the order of 10-100 μT do. Linear resonant physical processes do not explain the frequency windows in this case. Amplitude window phenomena suggest a nonlinear physical mechanism. Such a nonlinear mechanism has been proposed recently to explain those 'windows'. It considers the quantum-interference effects on the protein-bound substrate ions. Magnetic fields cause an interference of ion quantum states and change the probability of ion-protein dissociation. This ion-interference mechanism predicts specific magnetic-field frequency and amplitude windows within which the biological effects occur. It agrees with a lot of experiments. However, according to the mechanism, the lifetime Γ -1 of ion quantum states within a protein cavity should be of unrealistic value, more than 0.01 s for frequency band 10-100 Hz. In this paper, a biophysical mechanism has been proposed, which (i) retains the attractive features of the ion interference mechanism, i.e., predicts physical characteristics that might be experimentally examined and (ii) uses the principles of gyroscopic motion and removes the necessity to postulate large lifetimes. The mechanism considers the dynamics of the density matrix of the molecular groups, which are attached to the walls of protein cavities by two covalent bonds, i.e., molecular gyroscopes. Numerical computations have shown almost free rotations of the molecular gyroscopes. The relaxation time due to van der Waals forces was about 0.01 s for the cavity size of 28 Aa

Stochastic narrow escape in molecular and cellular biology analysis and applications

CERN Document Server

Holcman, David

2015-01-01

This book covers recent developments in the non-standard asymptotics of the mathematical narrow escape problem in stochastic theory, as well as applications of the narrow escape problem in cell biology. The first part of the book concentrates on mathematical methods, including advanced asymptotic methods in partial equations, and is aimed primarily at applied mathematicians and theoretical physicists who are interested in biological applications. The second part of the book is intended for computational biologists, theoretical chemists, biochemists, biophysicists, and physiologists. It includes a summary of output formulas from the mathematical portion of the book and concentrates on their applications in modeling specific problems in theoretical molecular and cellular biology. Critical biological processes, such as synaptic plasticity and transmission, activation of genes by transcription factors, or double-strained DNA break repair, are controlled by diffusion in structures that have both large and small sp...

On the shoulders of giants: Molecular Biology in Public Health

Directory of Open Access Journals (Sweden)

Carmine Melino

2005-03-01

Full Text Available

We accepted with great pleasure the invitation by professor Walter Ricciardi,our friend and colleague, to write an editorial in order to introduce this special issue dedicated to Molecular Biology in Hygiene. We are delighted for two connected reasons.

First, Carmine,as a former professor of Hygiene,has passed his concepts of Hygiene on to his family and, despite significant difficulties, keeps working on the problems of preventive medicine in the work environment and in geriatrics. Second, Gerry, raised in an environment of hygienists, has dedicated all his professional efforts to Molecular Biology. As these two distinct experiences have constantly mixed within our family over time, we appreciate the promiscuous intermingling of these two disciplines in this thematic issue.

The result is a useful common effort aiming at understanding the problems of diseases in the work environment and in the human environment in general.

These problems have a profound social meaning, for which it is necessary to create an essential collaboration with scientific research.

This is the only way to benefit human society.

Design of a Comprehensive Biochemistry and Molecular Biology Experiment: Phase Variation Caused by Recombinational Regulation of Bacterial Gene Expression

Science.gov (United States)

Sheng, Xiumei; Xu, Shungao; Lu, Renyun; Isaac, Dadzie; Zhang, Xueyi; Zhang, Haifang; Wang, Huifang; Qiao, Zheng; Huang, Xinxiang

2014-01-01

Scientific experiments are indispensable parts of Biochemistry and Molecular Biology. In this study, a comprehensive Biochemistry and Molecular Biology experiment about "Salmonella enterica" serovar Typhi Flagellar phase variation has been designed. It consisted of three parts, namely, inducement of bacterial Flagellar phase variation,…

Recent progress in structural biology: lessons from our research history.

Science.gov (United States)

Nitta, Ryo; Imasaki, Tsuyoshi; Nitta, Eriko

2018-05-16

The recent 'resolution revolution' in structural analyses of cryo-electron microscopy (cryo-EM) has drastically changed the research strategy for structural biology. In addition to X-ray crystallography and nuclear magnetic resonance spectroscopy, cryo-EM has achieved the structural analysis of biological molecules at near-atomic resolution, resulting in the Nobel Prize in Chemistry 2017. The effect of this revolution has spread within the biology and medical science fields affecting everything from basic research to pharmaceutical development by visualizing atomic structure. As we have used cryo-EM as well as X-ray crystallography since 2000 to elucidate the molecular mechanisms of the fundamental phenomena in the cell, here we review our research history and summarize our findings. In the first half of the review, we describe the structural mechanisms of microtubule-based motility of molecular motor kinesin by using a joint cryo-EM and X-ray crystallography method. In the latter half, we summarize our structural studies on transcriptional regulation by X-ray crystallography of in vitro reconstitution of a multi-protein complex.

Molecular biological factors in the diagnosis of cervical intraepithelial neoplasias

Directory of Open Access Journals (Sweden)

Yu. N. Ponomareva

2010-01-01

Full Text Available The authors have made a complex analysis of the molecular biological factors associated with cervical intraepithelial neoplasia. They have revealed that infection by oncogenic human papillomavirus types is associated with suppressed apoptosis and enhanced cellular proliferative activity, which can be effectively used in the diagnosis and prediction of cervical neoplasias to optimize management tac- tics and to improve the results of treatment.

WE-DE-202-03: Modeling of Biological Processes - What Happens After Early Molecular Damage?

International Nuclear Information System (INIS)

McMahon, S.

2016-01-01

Radiation therapy for the treatment of cancer has been established as a highly precise and effective way to eradicate a localized region of diseased tissue. To achieve further significant gains in the therapeutic ratio, we need to move towards biologically optimized treatment planning. To achieve this goal, we need to understand how the radiation-type dependent patterns of induced energy depositions within the cell (physics) connect via molecular, cellular and tissue reactions to treatment outcome such as tumor control and undesirable effects on normal tissue. Several computational biology approaches have been developed connecting physics to biology. Monte Carlo simulations are the most accurate method to calculate physical dose distributions at the nanometer scale, however simulations at the DNA scale are slow and repair processes are generally not simulated. Alternative models that rely on the random formation of individual DNA lesions within one or two turns of the DNA have been shown to reproduce the clusters of DNA lesions, including single strand breaks (SSBs), double strand breaks (DSBs) without the need for detailed track structure simulations. Efficient computational simulations of initial DNA damage induction facilitate computational modeling of DNA repair and other molecular and cellular processes. Mechanistic, multiscale models provide a useful conceptual framework to test biological hypotheses and help connect fundamental information about track structure and dosimetry at the sub-cellular level to dose-response effects on larger scales. In this symposium we will learn about the current state of the art of computational approaches estimating radiation damage at the cellular and sub-cellular scale. How can understanding the physics interactions at the DNA level be used to predict biological outcome? We will discuss if and how such calculations are relevant to advance our understanding of radiation damage and its repair, or, if the underlying biological

WE-DE-202-03: Modeling of Biological Processes - What Happens After Early Molecular Damage?

Energy Technology Data Exchange (ETDEWEB)

McMahon, S. [Massachusetts General Hospital and Harvard Medical School (United States)

2016-06-15

Radiation therapy for the treatment of cancer has been established as a highly precise and effective way to eradicate a localized region of diseased tissue. To achieve further significant gains in the therapeutic ratio, we need to move towards biologically optimized treatment planning. To achieve this goal, we need to understand how the radiation-type dependent patterns of induced energy depositions within the cell (physics) connect via molecular, cellular and tissue reactions to treatment outcome such as tumor control and undesirable effects on normal tissue. Several computational biology approaches have been developed connecting physics to biology. Monte Carlo simulations are the most accurate method to calculate physical dose distributions at the nanometer scale, however simulations at the DNA scale are slow and repair processes are generally not simulated. Alternative models that rely on the random formation of individual DNA lesions within one or two turns of the DNA have been shown to reproduce the clusters of DNA lesions, including single strand breaks (SSBs), double strand breaks (DSBs) without the need for detailed track structure simulations. Efficient computational simulations of initial DNA damage induction facilitate computational modeling of DNA repair and other molecular and cellular processes. Mechanistic, multiscale models provide a useful conceptual framework to test biological hypotheses and help connect fundamental information about track structure and dosimetry at the sub-cellular level to dose-response effects on larger scales. In this symposium we will learn about the current state of the art of computational approaches estimating radiation damage at the cellular and sub-cellular scale. How can understanding the physics interactions at the DNA level be used to predict biological outcome? We will discuss if and how such calculations are relevant to advance our understanding of radiation damage and its repair, or, if the underlying biological

Using Active Learning in a Studio Classroom to Teach Molecular Biology

Science.gov (United States)

Nogaj, Luiza A.

2013-01-01

This article describes the conversion of a lecture-based molecular biology course into an active learning environment in a studio classroom. Specific assignments and activities are provided as examples. The goal of these activities is to involve students in collaborative learning, teach them how to participate in the learning process, and give…

The isolated Leptospira Spp. Identification by molecular biological techniques

Directory of Open Access Journals (Sweden)

Duangjai Suwancharoen

2017-01-01

Full Text Available Leptospirosis is a zoonotic disease caused by the bacteria of Leptospira spp. Identification of this bacterium relies on serotyping and genotyping. Data base for animal causative serovars in Thailand is limited. As the unknown serovars are found in the laboratory, they need to be sent overseas for referent identification. To reduce the cost, this research intended to develop a leptospiral identification method which is user–friendly and able to classify efficiently. Ten Leptospira isolations were cultured from urine samples. They were identified by three molecular biological techniques, including Pulsed-Field Gel Electrophoresis (PFGE, Variable Number Tandem Repeat (VNTR and Multilocus Sequence Typing (MLST. These methods were developed and compared to find the most suitable one for leptospiral identification. VNTR was found to be inappropriate since it could not identify the agents and it did not show the PCR product. PFGE and MLST gave the same results of the unknown 1 and 2 which were L.weilii sv Samin st Samin. Unknown 4 showed different results by each technique. Unknown 5 to 10 were likely to be L.meyeri sv Ranarum st ICF and Leptonema illini sv Illini st 3055 by PFGE but MLST could not identify the serovar. However, molecular biological technique for Leptospira identification should be done by several methods in order to confirm the result of each other.

A biologically inspired two-species exclusion model: effects of RNA polymerase motor traffic on simultaneous DNA replication

Science.gov (United States)

Ghosh, Soumendu; Mishra, Bhavya; Patra, Shubhadeep; Schadschneider, Andreas; Chowdhury, Debashish

2018-04-01

We introduce a two-species exclusion model to describe the key features of the conflict between the RNA polymerase (RNAP) motor traffic, engaged in the transcription of a segment of DNA, concomitant with the progress of two DNA replication forks on the same DNA segment. One of the species of particles (P) represents RNAP motors while the other (R) represents the replication forks. Motivated by the biological phenomena that this model is intended to capture, a maximum of two R particles only are allowed to enter the lattice from two opposite ends whereas the unrestricted number of P particles constitutes a totally asymmetric simple exclusion process (TASEP) in a segment in the middle of the lattice. The model captures three distinct pathways for resolving the co-directional as well as head-on collision between the P and R particles. Using Monte Carlo simulations and heuristic analytical arguments that combine exact results for the TASEP with mean-field approximations, we predict the possible outcomes of the conflict between the traffic of RNAP motors (P particles engaged in transcription) and the replication forks (R particles). In principle, the model can be adapted to experimental conditions to account for the data quantitatively.

Simulations on the Teaching of Molecular Biology: Experience’s Report

Directory of Open Access Journals (Sweden)

A.L.S. Silva

2013-05-01

Full Text Available INTRODUCTION: The comprehension of techniques used in Molecular Biology neither always is easy.Therefore, the objective of this work was to apply simulations in Molecular Biology for graduating students of a Pharmacy course froma private educational institution, to allow them to practice the apparent difficult protocols. MATERIALS AND METHODS: Three groups of students (50 each were evaluated. Two of them were submitted to different simulatory activities,such as: a visiting the virtual laboratory of Utah University (USA to understand gel electrophoresis and polymerasechain reaction (PCR techniques, b extracting DNA from oral mucosa by means of a homemade protocol, c investigating simulatory paternity tests, d proposing their own microarrays by painting them on paper and then interpreted the results according to the colors, e designing primers (small fragments of DNA to PCR with the free software Primer3 and testing them in silico PCR. The third group of students was only submitted to oral theoretical classes about all these themes. The progress of the understanding was qualitatively evaluated and compared by the analysis of questionnaires. RESULTS AND DISCUSSION: The groups submitted to the virtual classes were responsive during the development of activities and had a better performance in the examinations than the group that had only theoretical classes, showing better comprehension about the themes. Their greatest difficult was the limitation in the English language to interact with the websites (they often asked about an alternative site in Portuguese. CONCLUSION: The didactical sequence involving exercises in websites by using freeware and recreational activities in classroom with graduating students of Pharmacy proved to be an effective tool in the learning of some of the techniques in Molecular Biology, mainly when a lab and some equipment are not available to perform practical activities

MBEToolbox: a Matlab toolbox for sequence data analysis in molecular biology and evolution

Directory of Open Access Journals (Sweden)

Xia Xuhua

2005-03-01

Full Text Available Abstract Background MATLAB is a high-performance language for technical computing, integrating computation, visualization, and programming in an easy-to-use environment. It has been widely used in many areas, such as mathematics and computation, algorithm development, data acquisition, modeling, simulation, and scientific and engineering graphics. However, few functions are freely available in MATLAB to perform the sequence data analyses specifically required for molecular biology and evolution. Results We have developed a MATLAB toolbox, called MBEToolbox, aimed at filling this gap by offering efficient implementations of the most needed functions in molecular biology and evolution. It can be used to manipulate aligned sequences, calculate evolutionary distances, estimate synonymous and nonsynonymous substitution rates, and infer phylogenetic trees. Moreover, it provides an extensible, functional framework for users with more specialized requirements to explore and analyze aligned nucleotide or protein sequences from an evolutionary perspective. The full functions in the toolbox are accessible through the command-line for seasoned MATLAB users. A graphical user interface, that may be especially useful for non-specialist end users, is also provided. Conclusion MBEToolbox is a useful tool that can aid in the exploration, interpretation and visualization of data in molecular biology and evolution. The software is publicly available at http://web.hku.hk/~jamescai/mbetoolbox/ and http://bioinformatics.org/project/?group_id=454.

Molecular motor transport through hollow nanowires

DEFF Research Database (Denmark)

Lard, Mercy; Ten Siethoff, Lasse; Generosi, Johanna

2014-01-01

-driven motion of fluorescent probes (actin filaments) through 80 nm wide, Al2O 3 hollow nanowires of micrometer length. The motor-driven transport is orders of magnitude faster than would be possible by passive diffusion. The system represents a necessary element for advanced devices based on gliding assays...

A guide on instrument of biochemistry and molecular biology

International Nuclear Information System (INIS)

1995-10-01

This book is about instrument on biochemistry and molecular biology, which consists of six chapters. It deals with introduction of advanced bio-instrument, common utilization and maintain, explanation of each instrument like capillary electrophoresis, interactive laser cytometer, personal computer and software, an electron microscope and DNA/RNS synthesis instrument, large equipment and special system like information system and network, analysis system for genome and large spectro graph, outside donation, examples for common utilization and appendix on data like application form for use.

Special conference of the American Association for Cancer Research on molecular imaging in cancer: linking biology, function, and clinical applications in vivo.

Science.gov (United States)

Luker, Gary D

2002-04-01

The AACR Special Conference on Molecular Imaging in Cancer: Linking Biology, Function, and Clinical Applications In Vivo, was held January 23-27, 2002, at the Contemporary Hotel, Walt Disney World, Orlando, FL. Co-Chairs David Piwnica-Worms, Patricia Price and Thomas Meade brought together researchers with diverse expertise in molecular biology, gene therapy, chemistry, engineering, pharmacology, and imaging to accelerate progress in developing and applying technologies for imaging specific cellular and molecular signals in living animals and humans. The format of the conference was the presentation of research that focused on basic and translational biology of cancer and current state-of-the-art techniques for molecular imaging in animal models and humans. This report summarizes the special conference on molecular imaging, highlighting the interfaces of molecular biology with animal models, instrumentation, chemistry, and pharmacology that are essential to convert the dreams and promise of molecular imaging into improved understanding, diagnosis, and management of cancer.

The neural optimal control hierarchy for motor control

Science.gov (United States)

DeWolf, T.; Eliasmith, C.

2011-10-01

Our empirical, neuroscientific understanding of biological motor systems has been rapidly growing in recent years. However, this understanding has not been systematically mapped to a quantitative characterization of motor control based in control theory. Here, we attempt to bridge this gap by describing the neural optimal control hierarchy (NOCH), which can serve as a foundation for biologically plausible models of neural motor control. The NOCH has been constructed by taking recent control theoretic models of motor control, analyzing the required processes, generating neurally plausible equivalent calculations and mapping them on to the neural structures that have been empirically identified to form the anatomical basis of motor control. We demonstrate the utility of the NOCH by constructing a simple model based on the identified principles and testing it in two ways. First, we perturb specific anatomical elements of the model and compare the resulting motor behavior with clinical data in which the corresponding area of the brain has been damaged. We show that damaging the assigned functions of the basal ganglia and cerebellum can cause the movement deficiencies seen in patients with Huntington's disease and cerebellar lesions. Second, we demonstrate that single spiking neuron data from our model's motor cortical areas explain major features of single-cell responses recorded from the same primate areas. We suggest that together these results show how NOCH-based models can be used to unify a broad range of data relevant to biological motor control in a quantitative, control theoretic framework.

DAE-BRNS life sciences symposium on molecular biology of stress response and its applications

International Nuclear Information System (INIS)

2005-01-01

The world of living organisms is full of challenges from their surroundings and these organisms learn to adapt themselves to the changes - some transient and some permanent - in these surroundings. The demands on adaptability to stress are very strong for extremophiles that live in harsh conditions such as cold or hot temperatures, salinity and hyperbaric habitats. The stress could be biotic (e.g. infection or parasitism) or abiotic (e.g. temperature, light, salinity, heavy metals etc.) Evolutionarily living organisms have developed different shapes, coloration, habits etc. to survive in their habitats. The molecular mechanisms of these biological adaptations have become clearer only in recent years from the studies on the biological responses of an organism to stresses during its life time. Such responses are characterized by activation of certain genes and synthesis of proteins and metabolites, which facilitate amelioration of the stress. The molecular biology (biochemistry and genetics) of stress response is being constantly unravelled thanks to the availability of highly sensitive and high throughput techniques and a plethora of extremophilic experimental systems such as archaebacteria, radio resistant bacteria and midges, plants surviving in cold etc. An interesting outcome of this voluminous research has been the knowledge that responses to a group of stresses share common mechanisms, at least in part. This reflects the biologically conservationist trend among otherwise diverse organisms and stresses. In this symposium several papers and posters in the area of molecular biology of stress are presented in addition to some very interesting and promising-to-be informative and stimulating plenary lectures and invited talks from highly reputed scientists. The papers relevant to INIS are indexed separately

Using whole mount in situ hybridization to link molecular and organismal biology.

Science.gov (United States)

Jacobs, Nicole L; Albertson, R Craig; Wiles, Jason R

2011-03-31

Whole mount in situ hybridization (WISH) is a common technique in molecular biology laboratories used to study gene expression through the localization of specific mRNA transcripts within whole mount specimen. This technique (adapted from Albertson and Yelick, 2005) was used in an upper level undergraduate Comparative Vertebrate Biology laboratory classroom at Syracuse University. The first two thirds of the Comparative Vertebrate Biology lab course gave students the opportunity to study the embryology and gross anatomy of several organisms representing various chordate taxa primarily via traditional dissections and the use of models. The final portion of the course involved an innovative approach to teaching anatomy through observation of vertebrate development employing molecular techniques in which WISH was performed on zebrafish embryos. A heterozygous fibroblast growth factor 8 a (fgf8a) mutant line, ace, was used. Due to Mendelian inheritance, ace intercrosses produced wild type, heterozygous, and homozygous ace/fgf8a mutants in a 1:2:1 ratio. RNA probes with known expression patterns in the midline and in developing anatomical structures such as the heart, somites, tailbud, myotome, and brain were used. WISH was performed using zebrafish at the 13 somite and prim-6 stages, with students performing the staining reaction in class. The study of zebrafish embryos at different stages of development gave students the ability to observe how these anatomical structures changed over ontogeny. In addition, some ace/fgf8a mutants displayed improper heart looping, and defects in somite and brain development. The students in this lab observed the normal development of various organ systems using both external anatomy as well as gene expression patterns. They also identified and described embryos displaying improper anatomical development and gene expression (i.e., putative mutants). For instructors at institutions that do not already own the necessary equipment or where

Hereditary spastic paraplegias: membrane traffic and the motor pathway.

Science.gov (United States)

Blackstone, Craig; O'Kane, Cahir J; Reid, Evan

2011-01-01

Voluntary movement is a fundamental way in which animals respond to, and interact with, their environment. In mammals, the main CNS pathway controlling voluntary movement is the corticospinal tract, which encompasses connections between the cerebral motor cortex and the spinal cord. Hereditary spastic paraplegias (HSPs) are a group of genetic disorders that lead to a length-dependent, distal axonopathy of fibres of the corticospinal tract, causing lower limb spasticity and weakness. Recent work aimed at elucidating the molecular cell biology underlying the HSPs has revealed the importance of basic cellular processes — especially membrane trafficking and organelle morphogenesis and distribution— in axonal maintenance and degeneration.

Cloning Yeast Actin cDNA Leads to an Investigative Approach for the Molecular Biology Laboratory

Science.gov (United States)

Black, Michael W.; Tuan, Alice; Jonasson, Erin

2008-01-01

The emergence of molecular tools in multiple disciplines has elevated the importance of undergraduate laboratory courses that train students in molecular biology techniques. Although it would also be desirable to provide students with opportunities to apply these techniques in an investigative manner, this is generally not possible in the…

Using Biocatalysis to Integrate Organic Chemistry into a Molecular Biology Laboratory Course

Science.gov (United States)

Beers, Mande; Archer, Crystal; Feske, Brent D.; Mateer, Scott C.

2012-01-01

Current cutting-edge biomedical investigation requires that the researcher have an operational understanding of several diverse disciplines. Biocatalysis is a field of science that operates at the crossroads of organic chemistry, biochemistry, microbiology, and molecular biology, and provides an excellent model for interdisciplinary research. We…

Forty Years of Ebolavirus Molecular Biology: Understanding a Novel Disease Agent Through the Development and Application of New Technologies.

Science.gov (United States)

Groseth, Allison; Hoenen, Thomas

2017-01-01

Molecular biology is a broad discipline that seeks to understand biological phenomena at a molecular level, and achieves this through the study of DNA, RNA, proteins, and/or other macromolecules (e.g., those involved in the modification of these substrates). Consequently, it relies on the availability of a wide variety of methods that deal with the collection, preservation, inactivation, separation, manipulation, imaging, and analysis of these molecules. As such the state of the art in the field of ebolavirus molecular biology research (and that of all other viruses) is largely intertwined with, if not driven by, advancements in the technical methodologies available for these kinds of studies. Here we review of the current state of our knowledge regarding ebolavirus biology and emphasize the associated methods that made these discoveries possible.

Centre for Cellular and Molecular Biology to breed vultures for Parsis

African Journals Online (AJOL)

Hyderabad – Parsis worried about the growing pile of bodies in their 'Towers of Silence' can take heart. The Centre for Cellular and Molecular Biology. (CCMB) has decided to take up, on an express basis, the job of breeding vultures, which can later be transported to various parts of the country. Though the problem of ...

Investigation of the Physical and Molecular Properties of Asphalt Binders Processed with Used Motor Oils

Directory of Open Access Journals (Sweden)

Mohyeldin Ragab

2015-01-01

Full Text Available In this work we investigated the performance aspects of addition of used motor oils (UMO to neat and crumb rubber modified asphalts (CRMA and related that to the change of molecular size distribution of modified asphalt’s fractions; asphaltenes, saturates, naphthene aromatics, and polar aromatics. Based on the results of temperature sweep viscoelastic tests, addition of crumb rubber modifier (CRM alone or with UMO results in the formation of internal network within the modified asphalt. Based on the results of short and long term aged asphalts, the utilization of combination of UMO and CRM enhanced the aging behavior of asphalt. Bending beam rheometer was utilized to investigate the low temperature behavior of UMO modified asphalts. Based on those tests, the utilization of the UMO and CRM enhanced the low temperature properties of asphalts. Based on the results of the asphalt separation tests and the Gel Permeation Chromatography (GPC analysis, it was found that saturates and naphthene aromatics are the two asphalt fractions that have similar molecular size fractions as those of UMO. However, UMO only shifts the molecular sizes of saturates after interaction with asphalt. Results also show that polar aromatics pose higher molecular size structures than UMO.

A logic-based dynamic modeling approach to explicate the evolution of the central dogma of molecular biology.

Science.gov (United States)

Jafari, Mohieddin; Ansari-Pour, Naser; Azimzadeh, Sadegh; Mirzaie, Mehdi

It is nearly half a century past the age of the introduction of the Central Dogma (CD) of molecular biology. This biological axiom has been developed and currently appears to be all the more complex. In this study, we modified CD by adding further species to the CD information flow and mathematically expressed CD within a dynamic framework by using Boolean network based on its present-day and 1965 editions. We show that the enhancement of the Dogma not only now entails a higher level of complexity, but it also shows a higher level of robustness, thus far more consistent with the nature of biological systems. Using this mathematical modeling approach, we put forward a logic-based expression of our conceptual view of molecular biology. Finally, we show that such biological concepts can be converted into dynamic mathematical models using a logic-based approach and thus may be useful as a framework for improving static conceptual models in biology.

A logic-based dynamic modeling approach to explicate the evolution of the central dogma of molecular biology.

Directory of Open Access Journals (Sweden)

Mohieddin Jafari

Full Text Available It is nearly half a century past the age of the introduction of the Central Dogma (CD of molecular biology. This biological axiom has been developed and currently appears to be all the more complex. In this study, we modified CD by adding further species to the CD information flow and mathematically expressed CD within a dynamic framework by using Boolean network based on its present-day and 1965 editions. We show that the enhancement of the Dogma not only now entails a higher level of complexity, but it also shows a higher level of robustness, thus far more consistent with the nature of biological systems. Using this mathematical modeling approach, we put forward a logic-based expression of our conceptual view of molecular biology. Finally, we show that such biological concepts can be converted into dynamic mathematical models using a logic-based approach and thus may be useful as a framework for improving static conceptual models in biology.

Primary Molecular Disorders and Secondary Biological Adaptations in Bartter Syndrome

Science.gov (United States)

Deschênes, Georges; Fila, Marc

2011-01-01

Bartter syndrome is a hereditary disorder that has been characterized by the association of hypokalemia, alkalosis, and the hypertrophy of the juxtaglomerular complex with secondary hyperaldosteronism and normal blood pressure. By contrast, the genetic causes of Bartter syndrome primarily affect molecular structures directly involved in the sodium reabsorption at the level of the Henle loop. The ensuing urinary sodium wasting and chronic sodium depletion are responsible for the contraction of the extracellular volume, the activation of the renin-aldosterone axis, the secretion of prostaglandins, and the biological adaptations of downstream tubular segments, meaning the distal convoluted tubule and the collecting duct. These secondary biological adaptations lead to hypokalemia and alkalosis, illustrating a close integration of the solutes regulation in the tubular structures. PMID:21941653

Primary Molecular Disorders and Secondary Biological Adaptations in Bartter Syndrome

Directory of Open Access Journals (Sweden)

Georges Deschênes

2011-01-01

Full Text Available Bartter syndrome is a hereditary disorder that has been characterized by the association of hypokalemia, alkalosis, and the hypertrophy of the juxtaglomerular complex with secondary hyperaldosteronism and normal blood pressure. By contrast, the genetic causes of Bartter syndrome primarily affect molecular structures directly involved in the sodium reabsorption at the level of the Henle loop. The ensuing urinary sodium wasting and chronic sodium depletion are responsible for the contraction of the extracellular volume, the activation of the renin-aldosterone axis, the secretion of prostaglandins, and the biological adaptations of downstream tubular segments, meaning the distal convoluted tubule and the collecting duct. These secondary biological adaptations lead to hypokalemia and alkalosis, illustrating a close integration of the solutes regulation in the tubular structures.

Molecular Biology and Infection of Hepatitis E Virus

Directory of Open Access Journals (Sweden)

Yuchen Nan

2016-09-01

Full Text Available Hepatitis E virus (HEV is a viral pathogen transmitted primarily via fecal-oral route. In humans, HEV mainly causes acute hepatitis and is responsible for large outbreaks of hepatitis across the world. The case fatality rate of HEV-induced hepatitis ranges from 0.5 to 3% in young adults and up to 30% in infected pregnant women. HEV strains infecting humans are classified into four genotypes. HEV strains from genotype 3 and 4 are zoonotic, whereas those from genotype 1 and 2 have no known animal reservoirs. Recently, notable progress has been accomplished for better understanding of HEV biology and infection, such as chronic HEV infection, in vitro cell culture system, quasi-enveloped HEV virions, functions of the HEV proteins, mechanism of HEV antagonizing host innate immunity, HEV pathogenesis and vaccine development. However, further investigation on the cross-species HEV infection, host tropism, vaccine efficacy and HEV-specific antiviral strategy is still needed. This review mainly focuses on molecular biology and infection of HEV and offers perspective new insight of this enigmatic virus.

Molecular insights into the biology of Greater Sage-Grouse

Science.gov (United States)

Oyler-McCance, Sara J.; Quinn, Thomas W.

2011-01-01

Recent research on Greater Sage-Grouse (Centrocercus urophasianus) genetics has revealed some important findings. First, multiple paternity in broods is more prevalent than previously thought, and leks do not comprise kin groups. Second, the Greater Sage-Grouse is genetically distinct from the congeneric Gunnison sage-grouse (C. minimus). Third, the Lyon-Mono population in the Mono Basin, spanning the border between Nevada and California, has unique genetic characteristics. Fourth, the previous delineation of western (C. u. phaios) and eastern Greater Sage-Grouse (C. u. urophasianus) is not supported genetically. Fifth, two isolated populations in Washington show indications that genetic diversity has been lost due to population declines and isolation. This chapter examines the use of molecular genetics to understand the biology of Greater Sage-Grouse for the conservation and management of this species and put it into the context of avian ecology based on selected molecular studies.

Progress in nucleic acid research and molecular biology

International Nuclear Information System (INIS)

Cohn, W.E.; Moldave, K.

1988-01-01

Complementary Use of Chemical Modification and Site-Directed Mutagenesis to Probe Structure-Activity Relationships in Enzymes. Mechanisms of the Antiviral Action of Inteferons. Modulation of Cellular Genes by Oncogenes. DNA Damage Produced by Ionizing Radiation in Mammalian Cells: Identities, Mechanisms of Formation, and Reparability. Human Ferritin Gene Expression. Molecular Biology of the Insulin Receptor. Cap-Binding Proteins of Eukaryotic Messenger RNA: Functions in Initiation and Control of Translation. Physical Monitoring of Meiotic and Mitotic Recombination in Yeast. Early Signals Underlying the Induction of the c-fos and c-myc Genes in Quiescent Fibroblasts: Studies with Bombesin and Other Growth Factors. Each chapter includes references

Effect of buffer at nanoscale molecular recognition interfaces - electrostatic binding of biological polyanions.

Science.gov (United States)

Rodrigo, Ana C; Laurini, Erik; Vieira, Vânia M P; Pricl, Sabrina; Smith, David K

2017-10-19

We investigate the impact of an over-looked component on molecular recognition in water-buffer. The binding of a cationic dye to biological polyanion heparin is shown by isothermal calorimetry to depend on buffer (Tris-HCl > HEPES > PBS). The heparin binding of self-assembled multivalent (SAMul) cationic micelles is even more buffer dependent. Multivalent electrostatic molecular recognition is buffer dependent as a result of competitive interactions between the cationic binding interface and anions present in the buffer.

Molecular machines open cell membranes.

Science.gov (United States)

García-López, Víctor; Chen, Fang; Nilewski, Lizanne G; Duret, Guillaume; Aliyan, Amir; Kolomeisky, Anatoly B; Robinson, Jacob T; Wang, Gufeng; Pal, Robert; Tour, James M

2017-08-30

Beyond the more common chemical delivery strategies, several physical techniques are used to open the lipid bilayers of cellular membranes. These include using electric and magnetic fields, temperature, ultrasound or light to introduce compounds into cells, to release molecular species from cells or to selectively induce programmed cell death (apoptosis) or uncontrolled cell death (necrosis). More recently, molecular motors and switches that can change their conformation in a controlled manner in response to external stimuli have been used to produce mechanical actions on tissue for biomedical applications. Here we show that molecular machines can drill through cellular bilayers using their molecular-scale actuation, specifically nanomechanical action. Upon physical adsorption of the molecular motors onto lipid bilayers and subsequent activation of the motors using ultraviolet light, holes are drilled in the cell membranes. We designed molecular motors and complementary experimental protocols that use nanomechanical action to induce the diffusion of chemical species out of synthetic vesicles, to enhance the diffusion of traceable molecular machines into and within live cells, to induce necrosis and to introduce chemical species into live cells. We also show that, by using molecular machines that bear short peptide addends, nanomechanical action can selectively target specific cell-surface recognition sites. Beyond the in vitro applications demonstrated here, we expect that molecular machines could also be used in vivo, especially as their design progresses to allow two-photon, near-infrared and radio-frequency activation.

Molecular machines open cell membranes

Science.gov (United States)

García-López, Víctor; Chen, Fang; Nilewski, Lizanne G.; Duret, Guillaume; Aliyan, Amir; Kolomeisky, Anatoly B.; Robinson, Jacob T.; Wang, Gufeng; Pal, Robert; Tour, James M.

2017-08-01

Beyond the more common chemical delivery strategies, several physical techniques are used to open the lipid bilayers of cellular membranes. These include using electric and magnetic fields, temperature, ultrasound or light to introduce compounds into cells, to release molecular species from cells or to selectively induce programmed cell death (apoptosis) or uncontrolled cell death (necrosis). More recently, molecular motors and switches that can change their conformation in a controlled manner in response to external stimuli have been used to produce mechanical actions on tissue for biomedical applications. Here we show that molecular machines can drill through cellular bilayers using their molecular-scale actuation, specifically nanomechanical action. Upon physical adsorption of the molecular motors onto lipid bilayers and subsequent activation of the motors using ultraviolet light, holes are drilled in the cell membranes. We designed molecular motors and complementary experimental protocols that use nanomechanical action to induce the diffusion of chemical species out of synthetic vesicles, to enhance the diffusion of traceable molecular machines into and within live cells, to induce necrosis and to introduce chemical species into live cells. We also show that, by using molecular machines that bear short peptide addends, nanomechanical action can selectively target specific cell-surface recognition sites. Beyond the in vitro applications demonstrated here, we expect that molecular machines could also be used in vivo, especially as their design progresses to allow two-photon, near-infrared and radio-frequency activation.

2012 Gordon Research Conference, Single molecule approaches to biology, July 15-20 2012

Energy Technology Data Exchange (ETDEWEB)

Fernandez, Julio M. [Columbia Univ., New York, NY (United States)

2012-04-20

Single molecule techniques are rapidly occupying a central role in biological research at all levels. This transition was made possible by the availability and dissemination of robust techniques that use fluorescence and force probes to track the conformation of molecules one at a time, in vitro as well as in live cells. Single-molecule approaches have changed the way many biological problems are studied. These novel techniques provide previously unobtainable data on fundamental biochemical processes that are essential for all forms of life. The ability of single-molecule approaches to avoid ensemble averaging and to capture transient intermediates and heterogeneous behavior renders them particularly powerful in elucidating mechanisms of the molecular systems that underpin the functioning of living cells. Hence, our conference seeks to disseminate the implementation and use of single molecule techniques in the pursuit of new biological knowledge. Topics covered include: Molecular Motors on the Move; Origin And Fate Of Proteins; Physical Principles Of Life; Molecules and Super-resolution Microscopy; Nanoswitches In Action; Active Motion Or Random Diffusion?; Building Blocks Of Living Cells; From Molecular Mechanics To Physiology; Tug-of-war: Force Spectroscopy Of Single Proteins.

Dictionary of microbiology and molecular biology. 2nd ed

Energy Technology Data Exchange (ETDEWEB)

Singleton, P.; Sainsbury, D.

1988-01-01

A newly revised edition of the standard reference for microbiology and molecular biology. Includes a multitude of new terms and designations which, although widely used in the literature, are seldom defined outside the book or paper in which they first appeared. Also accounts for the changes in the meanings of older terms brought about by advances in knowledge. Definition of all terms reflects their actual usage in current journals and texts, and also given (where appropriate) are former meanings, alternative meanings, and synonyms. Includes terms from such fields as mycology, protozoology, virology, etc.

Features of Knowledge Building in Biology: Understanding Undergraduate Students’ Ideas about Molecular Mechanisms

Science.gov (United States)

Southard, Katelyn; Wince, Tyler; Meddleton, Shanice; Bolger, Molly S.

2016-01-01

Research has suggested that teaching and learning in molecular and cellular biology (MCB) is difficult. We used a new lens to understand undergraduate reasoning about molecular mechanisms: the knowledge-integration approach to conceptual change. Knowledge integration is the dynamic process by which learners acquire new ideas, develop connections between ideas, and reorganize and restructure prior knowledge. Semistructured, clinical think-aloud interviews were conducted with introductory and upper-division MCB students. Interviews included a written conceptual assessment, a concept-mapping activity, and an opportunity to explain the biomechanisms of DNA replication, transcription, and translation. Student reasoning patterns were explored through mixed-method analyses. Results suggested that students must sort mechanistic entities into appropriate mental categories that reflect the nature of MCB mechanisms and that conflation between these categories is common. We also showed how connections between molecular mechanisms and their biological roles are part of building an integrated knowledge network as students develop expertise. We observed differences in the nature of connections between ideas related to different forms of reasoning. Finally, we provide a tentative model for MCB knowledge integration and suggest its implications for undergraduate learning. PMID:26931398

Experimental demonstration of a single-molecule electric motor.

Science.gov (United States)

Tierney, Heather L; Murphy, Colin J; Jewell, April D; Baber, Ashleigh E; Iski, Erin V; Khodaverdian, Harout Y; McGuire, Allister F; Klebanov, Nikolai; Sykes, E Charles H

2011-09-04

For molecules to be used as components in molecular machines, methods that couple individual molecules to external energy sources and that selectively excite motion in a given direction are required. Significant progress has been made in the construction of molecular motors powered by light and by chemical reactions, but electrically driven motors have not yet been built, despite several theoretical proposals for such motors. Here we report that a butyl methyl sulphide molecule adsorbed on a copper surface can be operated as a single-molecule electric motor. Electrons from a scanning tunnelling microscope are used to drive the directional motion of the molecule in a two-terminal setup. Moreover, the temperature and electron flux can be adjusted to allow each rotational event to be monitored at the molecular scale in real time. The direction and rate of the rotation are related to the chiralities of both the molecule and the tip of the microscope (which serves as the electrode), illustrating the importance of the symmetry of the metal contacts in atomic-scale electrical devices.

Motor contagion during human-human and human-robot interaction.

Directory of Open Access Journals (Sweden)

Ambra Bisio

Full Text Available Motor resonance mechanisms are known to affect humans' ability to interact with others, yielding the kind of "mutual understanding" that is the basis of social interaction. However, it remains unclear how the partner's action features combine or compete to promote or prevent motor resonance during interaction. To clarify this point, the present study tested whether and how the nature of the visual stimulus and the properties of the observed actions influence observer's motor response, being motor contagion one of the behavioral manifestations of motor resonance. Participants observed a humanoid robot and a human agent move their hands into a pre-specified final position or put an object into a container at various velocities. Their movements, both in the object- and non-object- directed conditions, were characterized by either a smooth/curvilinear or a jerky/segmented trajectory. These trajectories were covered with biological or non-biological kinematics (the latter only by the humanoid robot. After action observation, participants were requested to either reach the indicated final position or to transport a similar object into another container. Results showed that motor contagion appeared for both the interactive partner except when the humanoid robot violated the biological laws of motion. These findings suggest that the observer may transiently match his/her own motor repertoire to that of the observed agent. This matching might mediate the activation of motor resonance, and modulate the spontaneity and the pleasantness of the interaction, whatever the nature of the communication partner.

Motor contagion during human-human and human-robot interaction.

Science.gov (United States)

Bisio, Ambra; Sciutti, Alessandra; Nori, Francesco; Metta, Giorgio; Fadiga, Luciano; Sandini, Giulio; Pozzo, Thierry

2014-01-01

Motor resonance mechanisms are known to affect humans' ability to interact with others, yielding the kind of "mutual understanding" that is the basis of social interaction. However, it remains unclear how the partner's action features combine or compete to promote or prevent motor resonance during interaction. To clarify this point, the present study tested whether and how the nature of the visual stimulus and the properties of the observed actions influence observer's motor response, being motor contagion one of the behavioral manifestations of motor resonance. Participants observed a humanoid robot and a human agent move their hands into a pre-specified final position or put an object into a container at various velocities. Their movements, both in the object- and non-object- directed conditions, were characterized by either a smooth/curvilinear or a jerky/segmented trajectory. These trajectories were covered with biological or non-biological kinematics (the latter only by the humanoid robot). After action observation, participants were requested to either reach the indicated final position or to transport a similar object into another container. Results showed that motor contagion appeared for both the interactive partner except when the humanoid robot violated the biological laws of motion. These findings suggest that the observer may transiently match his/her own motor repertoire to that of the observed agent. This matching might mediate the activation of motor resonance, and modulate the spontaneity and the pleasantness of the interaction, whatever the nature of the communication partner.

Intravascular near-infrared fluorescence molecular imaging of atherosclerosis: toward coronary arterial visualization of biologically high-risk plaques

Science.gov (United States)

Calfon, Marcella A.; Vinegoni, Claudio; Ntziachristos, Vasilis; Jaffer, Farouc A.

2010-01-01

New imaging methods are urgently needed to identify high-risk atherosclerotic lesions prior to the onset of myocardial infarction, stroke, and ischemic limbs. Molecular imaging offers a new approach to visualize key biological features that characterize high-risk plaques associated with cardiovascular events. While substantial progress has been realized in clinical molecular imaging of plaques in larger arterial vessels (carotid, aorta, iliac), there remains a compelling, unmet need to develop molecular imaging strategies targeted to high-risk plaques in human coronary arteries. We present recent developments in intravascular near-IR fluorescence catheter-based strategies for in vivo detection of plaque inflammation in coronary-sized arteries. In particular, the biological, light transmission, imaging agent, and engineering principles that underlie a new intravascular near-IR fluorescence sensing method are discussed. Intravascular near-IR fluorescence catheters appear highly translatable to the cardiac catheterization laboratory, and thus may offer a new in vivo method to detect high-risk coronary plaques and to assess novel atherosclerosis biologics.

Abstracts of the 26. Annual meeting of the Brazilian Society on Biochemistry and Molecular Biology; Resumos da 26. reuniao anual da Sociedade Brasileira de Bioquimica e Biologia Molecular

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-07-01

This meeting was about biochemistry and molecular biology. It was discussed topics related to bio energetic, channels, transports, biotechnology, metabolism, cellular biology, immunology, toxicology, photobiology and pharmacology.

Abstracts of the 27. Annual meeting of the Brazilian Society on Biochemistry and Molecular Biology; Resumos da 27. reuniao anual da Sociedade Brasileira de Bioquimica e Biologia Molecular

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-07-01

This meeting was about biochemistry and molecular biology. It was discussed topics related to bio energetic, channels, transports, biotechnology, metabolism, cellular biology, immunology, toxicology, photobiology and pharmacology.

Molecular pathology and prostate cancer therapeutics: from biology to bedside.

Science.gov (United States)

Rodrigues, Daniel Nava; Butler, Lisa M; Estelles, David Lorente; de Bono, Johann S

2014-01-01

Prostate cancer (PCa) is the second most commonly diagnosed malignancy in men and has an extremely heterogeneous clinical behaviour. The vast majority of PCas are hormonally driven diseases in which androgen signalling plays a central role. The realization that castration-resistant prostate cancer (CRPC) continues to rely on androgen signalling prompted the development of new, effective androgen blocking agents. As the understanding of the molecular biology of PCas evolves, it is hoped that stratification of prostate tumours into distinct molecular entities, each with its own set of vulnerabilities, will be a feasible goal. Around half of PCas harbour rearrangements involving a member of the ETS transcription factor family. Tumours without this rearrangement include SPOP mutant as well as SPINK1-over-expressing subtypes. As the number of targeted therapy agents increases, it is crucial to determine which patients will benefit from these interventions and molecular pathology will be key in this respect. In addition to directly targeting cells, therapies that modify the tumour microenvironment have also been successful in prolonging the lives of PCa patients. Understanding the molecular aspects of PCa therapeutics will allow pathologists to provide core recommendations for patient management. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Foundational Concepts and Underlying Theories for Majors in "Biochemistry and Molecular Biology"

Science.gov (United States)

Tansey, John T.; Baird, Teaster, Jr.; Cox, Michael M.; Fox, Kristin M.; Knight, Jennifer; Sears, Duane; Bell, Ellis

2013-01-01

Over the past two years, through an NSF RCN UBE grant, the ASBMB has held regional workshops for faculty members and science educators from around the country that focused on identifying: 1) core principles of biochemistry and molecular biology, 2) essential concepts and underlying theories from physics, chemistry, and mathematics, and 3)…

Beyond a pedagogical tool: 30 years of Molecular biology of the cell.

Science.gov (United States)

Serpente, Norberto

2013-02-01

In 1983, a bulky and profusely illustrated textbook on molecular and cell biology began to inhabit the shelves of university libraries worldwide. The effect of capturing the eyes and souls of biologists was immediate as the book provided them with a new and invigorating outlook on what cells are and what they do.

An Off-the-Shelf, Authentic, and Versatile Undergraduate Molecular Biology Practical Course

Science.gov (United States)

Whitworth, David E.

2015-01-01

We provide a prepackaged molecular biology course, which has a broad context and is scalable to large numbers of students. It is provided complete with technical setup guidance, a reliable assessment regime, and can be readily implemented without any development necessary. Framed as a forensic examination of blue/white cloning plasmids, the course…

Molecular biology and riddle of cancer: the ‘Tom & Jerry’ show

Directory of Open Access Journals (Sweden)

Md. Al Mamun

2011-11-01

Full Text Available From the conventional Bird’s eye, cancer initiation and metastasis are generally intended to be understood beneath the light of classical clonal genetic, epigenetic and cancer stem cell model. But inspite decades of investigation, molecular biology has shown hard success to give Eagle’s eye in unraveling the riddle of cancer. And it seems, tiring Tom runs in vague behind naughty Jerry.

Retracted: Molecular Characterization and Biological Activity of Interferon-α in Indian Peafowl (Pavo cristatus).

Science.gov (United States)

Zhao, Hongjing; Wang, Yu; Liu, Juanjuan; Shao, Yizhi; Li, Jinglun; Chai, Hongliang; Xing, Mingwei

2017-08-07

DNA and Cell Biology (DNA&CB) is officially retracting the paper by Zhao H, Wang Y, Liu J, Shao Y, Li J, Chai H, Xing M, entitled, "Molecular Characterization and Biological activity of Interferon-α in Indian Peafowl (Pavo cristatus)," [Epub ahead of print]; 2017, DOI: 10.1089/dna.2017.3798. The Editor-in-Chief of DNA&CB, Dr. Carol Shoshkes Reiss, was alerted to a discrepancy between the findings in the article by Zhao et al., and those of others, about the absence of expression of ISG15 in chickens. Dr. Reiss requested from the authors a clarification in their observations and inquired about the failure to include relevant citations in the reference section of the paper. Based on the response from the authors, it appeared that they did not have the confidence in the data as they were not able to repeat the experiments, and were also unsure of the molecular probes that were used in the study. Therefore, the Editor has determined that the paper should be officially retracted from DNA and Cell Biology.

The Design and Transformation of Biofundamentals: A Nonsurvey Introductory Evolutionary and Molecular Biology Course.

Science.gov (United States)

Klymkowsky, Michael W; Rentsch, Jeremy D; Begovic, Emina; Cooper, Melanie M

2016-01-01

Many introductory biology courses amount to superficial surveys of disconnected topics. Often, foundational observations and the concepts derived from them and students' ability to use these ideas appropriately are overlooked, leading to unrealistic expectations and unrecognized learning obstacles. The result can be a focus on memorization at the expense of the development of a meaningful framework within which to consider biological phenomena. About a decade ago, we began a reconsideration of what an introductory course should present to students and the skills they need to master. The original Web-based course's design presaged many of the recommendations of the Vision and Change report; in particular, a focus on social evolutionary mechanisms, stochastic (evolutionary and molecular) processes, and core ideas (cellular continuity, evolutionary homology, molecular interactions, coupled chemical reactions, and molecular machines). Inspired by insights from the Chemistry, Life, the Universe & Everything general chemistry project, we transformed the original Web version into a (freely available) book with a more unified narrative flow and a set of formative assessments delivered through the beSocratic system. We outline how student responses to course materials are guiding future course modifications, in particular a more concerted effort at helping students to construct logical, empirically based arguments, explanations, and models. © 2016 M. W. Klymkowsky et al. CBE—Life Sciences Education © 2016 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Investigating Viruses during the Transformation of Molecular Biology.

Science.gov (United States)

Moss, Bernard

2017-03-10

This Reflections article describes my early work on viral enzymes and the discovery of mRNA capping, how my training in medicine and biochemistry merged as I evolved into a virologist, the development of viruses as vaccine vectors, and how scientific and technological developments during the 1970s and beyond set the stage for the interrogation of nearly every step in the reproductive cycle of vaccinia virus (VACV), a large DNA virus with about 200 genes. The reader may view this article as a work in progress, because I remain actively engaged in research at the National Institutes of Health (NIH) notwithstanding 50 memorable years there. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

The molecular genetics of the telomere biology disorders.

Science.gov (United States)

Bertuch, Alison A

2016-08-02

The importance of telomere function for human health is exemplified by a collection of Mendelian disorders referred to as the telomere biology disorders (TBDs), telomeropathies, or syndromes of telomere shortening. Collectively, the TBDs cover a spectrum of conditions from multisystem disease presenting in infancy to isolated disease presentations in adulthood, most notably idiopathic pulmonary fibrosis. Eleven genes have been found mutated in the TBDs to date, each of which is linked to some aspect of telomere maintenance. This review summarizes the molecular defects that result from mutations in these genes, highlighting recent advances, including the addition of PARN to the TBD gene family and the discovery of heterozygous mutations in RTEL1 as a cause of familial pulmonary fibrosis.

Diagnosis and management of differentiated thyroid cancer using molecular biology.

Science.gov (United States)

Witt, Robert L; Ferris, Robert L; Pribitkin, Edmund A; Sherman, Steven I; Steward, David L; Nikiforov, Yuri E

2013-04-01

To define molecular biology in clinical practice for diagnosis, surgical management, and prognostication of differentiated thyroid cancer. Ovid Medline 2006-2012 Manuscripts with clinical correlates. Papillary thyroid carcinomas harbor point mutations of the BRAF and RAS genes or RET/PTC rearrangements, all of which activate the mitogen-activated protein kinase pathway. These mutually exclusive mutations are found in 70% of PTC. BRAF mutation is found in 45% of papillary thyroid cancer and is highly specific. Follicular carcinomas are known to harbor RAS mutation or PAX8/PPARγ rearrangement. These mutations are also mutually exclusive and identified in 70% of follicular carcinomas. Molecular classifiers measure the expression of a large number of genes on a microarray chip providing a substantial negative predictive value pending further validation. 1) 20% to 30% of cytologically classified Follicular Neoplasms and Follicular Lesion of Undetermined Significance collectively are malignant on final pathology. Approximately 70% to 80% of thyroid lobectomies performed solely for diagnostic purposes are benign. Molecular alteration testing may reduce the number of unnecessary thyroid procedures, 2) may reduce the number of completion thyroidectomies, and 3) may lead to more individualized operative and postoperative management. Molecular testing for BRAF, RAS, RET/PTC, and PAX8/PPARγ for follicular lesion of undetermined significance and follicular neoplasm improve specificity, whereas molecular classifiers may add negative predictive value to fine needle aspiration diagnosis. Copyright © 2013 The American Laryngological, Rhinological, and Otological Society, Inc.

[Etiologic diagnosis in meningitis and encephalitis molecular biology techniques].

Science.gov (United States)

Conca, Natalia; Santolaya, María Elena; Farfan, Mauricio J; Cofré, Fernanda; Vergara, Alejandra; Salazar, Liliana; Torres, Juan Pablo

2016-01-01

The aetiological study of infections of the central nervous system has traditionally been performed using bacterial cultures and, more recently, using polymerase chain reaction (PCR) for herpes simplex virus (HSV). Bacterial cultures may not have good performance, especially in the context of patients who have received antibiotics prior to sampling, and a request for HSV only by PCR reduces the information to only one aetiological agent. The aim of this study is to determine the infectious causes of meningitis and encephalitis, using traditional microbiology and molecular biology to improve the aetiological diagnosis of these diseases. A prospective study was conducted on 19 patients with suspected meningitis, admitted to the Luis Calvo Mackenna Hospital in Santiago, Chile, from March 1, 2011 to March 30, 2012. After obtaining informed consent, the CSF samples underwent cytochemical study, conventional culture, multiplex PCR for the major producing bacterial meningitis (N. meningitidis, S. pneumoniae, H. influenzae), real-time single PCR for HSV-1 and 2, VZV, EBV, CMV, HHV-6 and enterovirus. Clinical and epidemiological data were also collected from the clinical records. Of the 19 patients analysed, 2 were diagnosed by conventional methods and 7 by adding molecular biology (increase to 37%). Three patients had meningitis due to S. pneumoniae, one due to Enterobacter cloacae, 2 patients meningoencephalitis HSV-1, and one VZV meningitis. The addition of PCR to conventional diagnostic methods in CNS infections increases the probability of finding the causal agent. This allows a more adequate, timely and rational management of the disease. Copyright © 2014. Publicado por Elsevier España, S.L.U.

Sclerotinia sclerotiorum (Lib.) de Bary: biology and molecular traits of a cosmopolitan pathogen

NARCIS (Netherlands)

Bolton, M.D.; Thomma, B.P.H.J.; Nelson, B.D.

2006-01-01

Sclerotinia sclerotiorum (Lib.) de Bary is a necrotrophic fungal pathogen causing disease in a wide range of plants. This review summarizes current knowledge of mechanisms employed by the fungus to parasitize its host with emphasis on biology, physiology and molecular aspects of pathogenicity. In

Hidden Markov models and other machine learning approaches in computational molecular biology

Energy Technology Data Exchange (ETDEWEB)

Baldi, P. [California Inst. of Tech., Pasadena, CA (United States)

1995-12-31

This tutorial was one of eight tutorials selected to be presented at the Third International Conference on Intelligent Systems for Molecular Biology which was held in the United Kingdom from July 16 to 19, 1995. Computational tools are increasingly needed to process the massive amounts of data, to organize and classify sequences, to detect weak similarities, to separate coding from non-coding regions, and reconstruct the underlying evolutionary history. The fundamental problem in machine learning is the same as in scientific reasoning in general, as well as statistical modeling: to come up with a good model for the data. In this tutorial four classes of models are reviewed. They are: Hidden Markov models; artificial Neural Networks; Belief Networks; and Stochastic Grammars. When dealing with DNA and protein primary sequences, Hidden Markov models are one of the most flexible and powerful alignments and data base searches. In this tutorial, attention is focused on the theory of Hidden Markov Models, and how to apply them to problems in molecular biology.

Infusing Bioinformatics and Research-Like Experience into a Molecular Biology Laboratory Course

Science.gov (United States)

Nogaj, Luiza A.

2014-01-01

A nine-week laboratory project designed for a sophomore level molecular biology course is described. Small groups of students (3-4 per group) choose a tumor suppressor gene (TSG) or an oncogene for this project. Each group researches the role of their TSG/oncogene from primary literature articles and uses bioinformatics engines to find the gene…

Intraductal papillary-mucinous neoplasia of the pancreas: Histopathology and molecular biology

OpenAIRE

Verbeke, Caroline S

2010-01-01

Intraductal papillary-mucinous neoplasm (IPMN) of the pancreas is a clinically and morphologically distinctive precursor lesion of pancreatic cancer, characterized by gradual progression through a sequence of neoplastic changes. Based on the nature of the constituting neoplastic epithelium, degree of dysplasia and location within the pancreatic duct system, IPMNs are divided in several types which differ in their biological properties and clinical outcome. Molecular analysis and recent animal...

Exploring Visuomotor Priming Following Biological and Non-Biological Stimuli

Science.gov (United States)

Gowen, E.; Bradshaw, C.; Galpin, A.; Lawrence, A.; Poliakoff, E.

2010-01-01

Observation of human actions influences the observer's own motor system, termed visuomotor priming, and is believed to be caused by automatic activation of mirror neurons. Evidence suggests that priming effects are larger for biological (human) as opposed to non-biological (object) stimuli and enhanced when viewing stimuli in mirror compared to…

Biología y regulación molecular de la micorriza arbuscular

Directory of Open Access Journals (Sweden)

S. Guzmán-González

2005-01-01

Full Text Available Las micorrizas arbusculares son asociaciones simbióticas formadas entre un amplio rango de especies de plantas y hongos del orden Glomales. El hongo coloniza el apoplasto y células corticales de la raíz. El desarrollo de esta asociación, altamente compatible, requiere de la diferenciación celular y molecular coordinada de ambos simbiontes, para formar una interface especializada en la cual ocurre la transferencia bidireccional de nutrimentos. Esta revisión resume los resultados obtenidos con el uso de técnicas de biología molecular en el entendimiento del desarrollo de la simbiosis micorrízica arbuscular.

Biochemistry and Molecular Biology of Flaviviruses.

Science.gov (United States)

Barrows, Nicholas J; Campos, Rafael K; Liao, Kuo-Chieh; Prasanth, K Reddisiva; Soto-Acosta, Ruben; Yeh, Shih-Chia; Schott-Lerner, Geraldine; Pompon, Julien; Sessions, October M; Bradrick, Shelton S; Garcia-Blanco, Mariano A

2018-04-25

Flaviviruses, such as dengue, Japanese encephalitis, tick-borne encephalitis, West Nile, yellow fever, and Zika viruses, are critically important human pathogens that sicken a staggeringly high number of humans every year. Most of these pathogens are transmitted by mosquitos, and not surprisingly, as the earth warms and human populations grow and move, their geographic reach is increasing. Flaviviruses are simple RNA-protein machines that carry out protein synthesis, genome replication, and virion packaging in close association with cellular lipid membranes. In this review, we examine the molecular biology of flaviviruses touching on the structure and function of viral components and how these interact with host factors. The latter are functionally divided into pro-viral and antiviral factors, both of which, not surprisingly, include many RNA binding proteins. In the interface between the virus and the hosts we highlight the role of a noncoding RNA produced by flaviviruses to impair antiviral host immune responses. Throughout the review, we highlight areas of intense investigation, or a need for it, and potential targets and tools to consider in the important battle against pathogenic flaviviruses.

Oligometastatic prostate cancer: shaping the definition with molecular imaging and an improved understanding of tumor biology.

Science.gov (United States)

Joice, Gregory A; Rowe, Steven P; Pienta, Kenneth J; Gorin, Michael A

2017-11-01

The aim of this review is to discuss how novel imaging modalities and molecular markers are shaping the definition of oligometastatic prostate cancer. To effectively classify a patient as having oligometastatic prostate cancer, diagnostic tests must be sensitive enough to detect subtle sites of metastatic disease. Conventional imaging modalities can readily detect widespread polymetastatic disease but do not have the sensitivity necessary to reliably classify patients as oligometastatic. Molecular imaging using both metabolic- and molecularly-targeted radiotracers has demonstrated great promise in aiding in our ability to define the oligometastatic state. Perhaps the most promising data to date have been generated with radiotracers targeting prostate-specific membrane antigen. In addition, early studies are beginning to define biologic markers in the oligometastatic state that may be indicative of disease with minimal metastatic potential. Recent developments in molecular imaging have allowed for improved detection of metastatic prostate cancer allowing for more accurate staging of patients with oligometastatic disease. Future development of biologic markers may assist in defining the oligometastatic state and determining prognosis.

Integr8: enhanced inter-operability of European molecular biology databases.

Science.gov (United States)

Kersey, P J; Morris, L; Hermjakob, H; Apweiler, R

2003-01-01

The increasing production of molecular biology data in the post-genomic era, and the proliferation of databases that store it, require the development of an integrative layer in database services to facilitate the synthesis of related information. The solution of this problem is made more difficult by the absence of universal identifiers for biological entities, and the breadth and variety of available data. Integr8 was modelled using UML (Universal Modelling Language). Integr8 is being implemented as an n-tier system using a modern object-oriented programming language (Java). An object-relational mapping tool, OJB, is being used to specify the interface between the upper layers and an underlying relational database. The European Bioinformatics Institute is launching the Integr8 project. Integr8 will be an automatically populated database in which we will maintain stable identifiers for biological entities, describe their relationships with each other (in accordance with the central dogma of biology), and store equivalences between identified entities in the source databases. Only core data will be stored in Integr8, with web links to the source databases providing further information. Integr8 will provide the integrative layer of the next generation of bioinformatics services from the EBI. Web-based interfaces will be developed to offer gene-centric views of the integrated data, presenting (where known) the links between genome, proteome and phenotype.

The Molecular Biology of Soft-Tissue Sarcomas and Current Trends in Therapy

Directory of Open Access Journals (Sweden)

Jorge Quesada

2012-01-01

Full Text Available Basic research in sarcoma models has been fundamental in the discovery of scientific milestones leading to a better understanding of the molecular biology of cancer. Yet, clinical research in sarcoma has lagged behind other cancers because of the multiple clinical and pathological entities that characterize sarcomas and their rarity. Sarcomas encompass a very heterogeneous group of tumors with diverse pathological and clinical overlapping characteristics. Molecular testing has been fundamental in the identification and better definition of more specific entities among this vast array of malignancies. A group of sarcomas are distinguished by specific molecular aberrations such as somatic mutations, intergene deletions, gene amplifications, reciprocal translocations, and complex karyotypes. These and other discoveries have led to a better understanding of the growth signals and the molecular pathways involved in the development of these tumors. These findings are leading to treatment strategies currently under intense investigation. Disruption of the growth signals is being targeted with antagonistic antibodies, tyrosine kinase inhibitors, and inhibitors of several downstream molecules in diverse molecular pathways. Preliminary clinical trials, supported by solid basic research and strong preclinical evidence, promises a new era in the clinical management of these broad spectrum of malignant tumors.

Transmission electron microscopy in molecular structural biology: A historical survey.

Science.gov (United States)

Harris, J Robin

2015-09-01

In this personal, historic account of macromolecular transmission electron microscopy (TEM), published data from the 1940s through to recent times is surveyed, within the context of the remarkable progress that has been achieved during this time period. The evolution of present day molecular structural biology is described in relation to the associated biological disciplines. The contribution of numerous electron microscope pioneers to the development of the subject is discussed. The principal techniques for TEM specimen preparation, thin sectioning, metal shadowing, negative staining and plunge-freezing (vitrification) of thin aqueous samples are described, with a selection of published images to emphasise the virtues of each method. The development of digital image analysis and 3D reconstruction is described in detail as applied to electron crystallography and reconstructions from helical structures, 2D membrane crystals as well as single particle 3D reconstruction of icosahedral viruses and macromolecules. The on-going development of new software, algorithms and approaches is highlighted before specific examples of the historical progress of the structural biology of proteins and viruses are presented. Copyright © 2014 Elsevier Inc. All rights reserved.

Current status of molecular biological techniques for plant breeding in the Republic of Korea

Energy Technology Data Exchange (ETDEWEB)

Sohn, Seong-Han; Lee, Si-Myung; Park, Bum-Seok; Yun, In-Sun; Goo, Doe-Hoe; Kim, Seok-Dong [Rural Development Administration, National Institute of Agricultural Science and Technology, Suwon (Korea)

2002-02-01

Classical plant breeding has played an important role in developing new varieties in current agriculture. For decades, the technique of cross-pollination has been popular for breeding in cereal and horticultural crops to introduce special traits. However, recently the molecular techniques get widely accepted as an alternative tool in both introducing a useful trait for developing the new cultivars and investigating the characteristics of a trait in plant, like the identification of a gene. Using the advanced molecular technique, several genetically modified (GM) crops (e.g., Roundup Ready Soybean, YieldGard, LibertyLink etc.) became commercially cultivated and appeared in the global market since 1996. The GM crops, commercially available at the moment, could be regarded as successful achievements in history of crop breeding conferring the specific gene into economically valuable crops to make them better. Along with such achievements, on the other hand these new crops have also caused the controversial debate on the safety of GM crops as human consumption and environmental release as well. Nevertheless, molecular techniques are widespread and popular in both investigating the basic science of plant biology and breeding new varieties compared to their conventional counterparts. Thus, the Department of Bioresources at the National Institute of Agricultural Science and Technology (NIAST) has been using the molecular biological techniques as a complimentary tool for the improvement of crop varieties for almost two decades. (author)

Elements in nucleotide sensing and hydrolysis of the AAA+ disaggregation machine ClpB: a structure-based mechanistic dissection of a molecular motor

Energy Technology Data Exchange (ETDEWEB)

Zeymer, Cathleen, E-mail: cathleen.zeymer@mpimf-heidelberg.mpg.de; Barends, Thomas R. M.; Werbeck, Nicolas D.; Schlichting, Ilme; Reinstein, Jochen, E-mail: cathleen.zeymer@mpimf-heidelberg.mpg.de [Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg (Germany)

2014-02-01

High-resolution crystal structures together with mutational analysis and transient kinetics experiments were utilized to understand nucleotide sensing and the regulation of the ATPase cycle in an AAA+ molecular motor. ATPases of the AAA+ superfamily are large oligomeric molecular machines that remodel their substrates by converting the energy from ATP hydrolysis into mechanical force. This study focuses on the molecular chaperone ClpB, the bacterial homologue of Hsp104, which reactivates aggregated proteins under cellular stress conditions. Based on high-resolution crystal structures in different nucleotide states, mutational analysis and nucleotide-binding kinetics experiments, the ATPase cycle of the C-terminal nucleotide-binding domain (NBD2), one of the motor subunits of this AAA+ disaggregation machine, is dissected mechanistically. The results provide insights into nucleotide sensing, explaining how the conserved sensor 2 motif contributes to the discrimination between ADP and ATP binding. Furthermore, the role of a conserved active-site arginine (Arg621), which controls binding of the essential Mg{sup 2+} ion, is described. Finally, a hypothesis is presented as to how the ATPase activity is regulated by a conformational switch that involves the essential Walker A lysine. In the proposed model, an unusual side-chain conformation of this highly conserved residue stabilizes a catalytically inactive state, thereby avoiding unnecessary ATP hydrolysis.

Elements in nucleotide sensing and hydrolysis of the AAA+ disaggregation machine ClpB: a structure-based mechanistic dissection of a molecular motor

International Nuclear Information System (INIS)

Zeymer, Cathleen; Barends, Thomas R. M.; Werbeck, Nicolas D.; Schlichting, Ilme; Reinstein, Jochen

2014-01-01

High-resolution crystal structures together with mutational analysis and transient kinetics experiments were utilized to understand nucleotide sensing and the regulation of the ATPase cycle in an AAA+ molecular motor. ATPases of the AAA+ superfamily are large oligomeric molecular machines that remodel their substrates by converting the energy from ATP hydrolysis into mechanical force. This study focuses on the molecular chaperone ClpB, the bacterial homologue of Hsp104, which reactivates aggregated proteins under cellular stress conditions. Based on high-resolution crystal structures in different nucleotide states, mutational analysis and nucleotide-binding kinetics experiments, the ATPase cycle of the C-terminal nucleotide-binding domain (NBD2), one of the motor subunits of this AAA+ disaggregation machine, is dissected mechanistically. The results provide insights into nucleotide sensing, explaining how the conserved sensor 2 motif contributes to the discrimination between ADP and ATP binding. Furthermore, the role of a conserved active-site arginine (Arg621), which controls binding of the essential Mg 2+ ion, is described. Finally, a hypothesis is presented as to how the ATPase activity is regulated by a conformational switch that involves the essential Walker A lysine. In the proposed model, an unusual side-chain conformation of this highly conserved residue stabilizes a catalytically inactive state, thereby avoiding unnecessary ATP hydrolysis

Artificial microRNAs and their applications in plant molecular biology

Directory of Open Access Journals (Sweden)

Pérez-Quintero Álvaro Luis

2010-11-01

Full Text Available

Errant life, molecular biology, and biopower: Canguilhem, Jacob, and Foucault.

Science.gov (United States)

Talcott, Samuel

2014-01-01

This paper considers the theoretical circumstances that urged Michel Foucault to analyse modern societies in terms of biopower. Georges Canguilhem's account of the relations between science and the living forms an essential starting point for Foucault's own later explorations, though the challenges posed by the molecular revolution in biology and François Jacob's history of it allowed Foucault to extend and transform Canguilhem's philosophy of error. Using archival research into his 1955-1956 course on "Science and Error," I show that, for Canguilhem, it is inauthentic to treat a living being as an error, even if living things are capable of making errors in the domain of knowledge. The emergent molecular biology in the 1960s posed a grave challenge, however, since it suggested that individuals could indeed be errors of genetic reproduction. The paper discusses how Canguilhem and Foucault each responded to this by examining, among other texts, their respective reviews of Jacob's The Logic of the Living. For Canguilhem this was an opportunity to reaffirm the creativity of life in the living individual, which is not a thing to be evaluated, but the source of values. For Foucault, drawing on Jacob's work, this was the opportunity to develop a transformed account of valuation by posing biopower as the DNA of society. Despite their disagreements, the paper examines these three authors as different iterations of a historical epistemology attuned to errancy, error, and experimentation.

Molecular Sociology: Further Insights from Biological and Environmental Aspects

Directory of Open Access Journals (Sweden)

Ahed Jumah Mahmoud Al-Khatib

2015-11-01

Full Text Available The present study expanded our previous study in which features of molecular sociology were mentioned. In this study, we added the microbial dimensions in which it is thought that religiosity may be impacted by microbes that manipulate brains to create better conditions for their existence. This hypothesis is called “biomeme hypothesis”. We talked about other environmental impacts on human behaviors through three studies in which exposure to lead caused violent behaviors ending with arresting in prisons. By conclusion, the present study has expanded our horizon about interferences on various levels including biological and environmental impacts with our behaviors. Although we are convinced that behavior is a very diverse and complex phenomenon and cannot be understood within certain frame as either biologically or environmentally, but further new insights are possible to participate in better understanding of human behaviors. Many behaviors have their roots in religion, and we showed how religious rituals may be affected by some microbes that make to form a microenvironment within the host for microbial benefits.

Novel thrombopoietin mimetic peptides bind c-Mpl receptor: Synthesis, biological evaluation and molecular modeling.

Science.gov (United States)

Liu, Yaquan; Tian, Fang; Zhi, Dejuan; Wang, Haiqing; Zhao, Chunyan; Li, Hongyu

2017-02-01

Thrombopoietin (TPO) acts in promoting the proliferation of hematopoietic stem cells and by initiating specific maturation events in megakaryocytes. Now, TPO-mimetic peptides with amino acid sequences unrelated to TPO are of considerable pharmaceutical interest. In the present paper, four new TPO mimetic peptides that bind and activate c-Mpl receptor have been identified, synthesized and tested by Dual-Luciferase reporter gene assay for biological activities. The molecular modeling research was also approached to understand key molecular mechanisms and structural features responsible for peptide binding with c-Mpl receptor. The results presented that three of four mimetic peptides showed significant activities. In addition, the molecular modeling approaches proved hydrophobic interactions were the driven positive forces for binding behavior between peptides and c-Mpl receptor. TPO peptide residues in P7, P13 and P7' positions were identified by the analysis of hydrogen bonds and energy decompositions as the key ones for benefiting better biological activities. Our data suggested the synthesized peptides have considerable potential for the future development of stable and highly active TPO mimetic peptides. Copyright © 2016 Elsevier Ltd. All rights reserved.

Right Versus Left Colon Cancer Biology: Integrating the Consensus Molecular Subtypes.

Science.gov (United States)

Lee, Michael S; Menter, David G; Kopetz, Scott

2017-03-01

Although clinical management of colon cancer generally has not accounted for the primary tumor site, left-sided and right-sided colon cancers harbor different clinical and biologic characteristics. Right-sided colon cancers are more likely to have genome-wide hypermethylation via the CpG island methylator phenotype (CIMP), hypermutated state via microsatellite instability, and BRAF mutation. There are also differential exposures to potential carcinogenic toxins and microbiota in the right and left colon. Gene expression analyses further shed light on distinct biologic subtypes of colorectal cancers (CRCs), with 4 consensus molecular subtypes (CMSs) identified. Importantly, these subtypes are differentially distributed between right- and left-sided CRCs, with greater proportions of the "microsatellite unstable/immune" CMS1 and the "metabolic" CMS3 subtypes found in right-sided colon cancers. This review summarizes important biologic distinctions between right- and left-sided CRCs that likely impact prognosis and may predict for differential responses to biologic therapy. Given the inferior prognosis of stage III-IV right-sided CRCs and emerging data suggesting that anti-epidermal growth factor receptor antibody therapy is associated with worse survival in right-sided stage IV CRCs compared with left-sided cancers, these biologic differences between right- and left-sided CRCs provide critical context and may provide opportunities to personalize therapy. Copyright © 2017 by the National Comprehensive Cancer Network.

Microgravity research in plant biological systems: Realizing the potential of molecular biology

Science.gov (United States)

Lewis, Norman G.; Ryan, Clarence A.

1993-01-01

The sole all-pervasive feature of the environment that has helped shape, through evolution, all life on Earth is gravity. The near weightlessness of the Space Station Freedom space environment allows gravitational effects to be essentially uncoupled, thus providing an unprecedented opportunity to manipulate, systematically dissect, study, and exploit the role of gravity in the growth and development of all life forms. New and exciting opportunities are now available to utilize molecular biological and biochemical approaches to study the effects of microgravity on living organisms. By careful experimentation, we can determine how gravity perception occurs, how the resulting signals are produced and transduced, and how or if tissue-specific differences in gene expression occur. Microgravity research can provide unique new approaches to further our basic understanding of development and metabolic processes of cells and organisms, and to further the application of this new knowledge for the betterment of humankind.

Molecular codes in biological and chemical reaction networks.

Directory of Open Access Journals (Sweden)

Dennis Görlich

Full Text Available Shannon's theory of communication has been very successfully applied for the analysis of biological information. However, the theory neglects semantic and pragmatic aspects and thus cannot directly be applied to distinguish between (bio- chemical systems able to process "meaningful" information from those that do not. Here, we present a formal method to assess a system's semantic capacity by analyzing a reaction network's capability to implement molecular codes. We analyzed models of chemical systems (martian atmosphere chemistry and various combustion chemistries, biochemical systems (gene expression, gene translation, and phosphorylation signaling cascades, an artificial chemistry, and random reaction networks. Our study suggests that different chemical systems possess different semantic capacities. No semantic capacity was found in the model of the martian atmosphere chemistry, the studied combustion chemistries, and highly connected random networks, i.e. with these chemistries molecular codes cannot be implemented. High semantic capacity was found in the studied biochemical systems and in random reaction networks where the number of second order reactions is twice the number of species. We conclude that our approach can be applied to evaluate the information processing capabilities of a chemical system and may thus be a useful tool to understand the origin and evolution of meaningful information, e.g. in the context of the origin of life.

Plant Molecular Biology 2008 Gordon Research Conference - July 13-18, 2008

Energy Technology Data Exchange (ETDEWEB)

Richard M. Amasino

2009-08-28

The Plant Molecular Biology Conference has traditionally covered a breadth of exciting topics and the 2008 conference will continue in that tradition. There will be sessions on metabolism; new methods to study genomes, proteomes and metabolomes; plant-microbe interactions; plant hormones; epigenetics. A new topic for the conference this year will be bioenergy. Thus this conference will bring together a range of disciplines to foster the exchange ideas and to permit the participants to learn of the latest developments and ideas in diverse areas of plant biology. The conference provides an excellent opportunity for individuals to discuss their research because additional speakers in each session will be selected from submitted abstracts. There will also be a poster session each day for a two-hour period prior to dinner.

Single amino acid substitution in important hemoglobinopathies does not disturb molecular function and biological process

Directory of Open Access Journals (Sweden)

Viroj Wiwanitkit

2008-06-01

Full Text Available Viroj WiwanitkitDepartment of Laboratory Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, ThailandAbstract: Hemoglobin is an important protein found in the red cells of many animals. In humans, the hemoglobin is mainly distributed in the red blood cell. Single amino acid substitution is the main pathogenesis of most hemoglobin disorders. Here, the author used a new gene ontology technology to predict the molecular function and biological process of four important hemoglobin disorders with single substitution. The four studied important abnormal hemoglobins (Hb with single substitution included Hb S, Hb E, Hb C, and Hb J-Baltimore. Using the GoFigure server, the molecular function and biological process in normal and abnormal hemoglobins was predicted. Compared with normal hemoglobin, all studied abnormal hemoglobins had the same function and biological process. This indicated that the overall function of oxygen transportation is not disturbed in the studied hemoglobin disorders. Clinical findings of oxygen depletion in abnormal hemoglobin should therefore be due to the other processes rather than genomics, proteomics, and expression levels.Keywords: hemoglobin, amino acid, substitution, function

Insights into the immuno-molecular biology of Angiostrongylus vasorum through transcriptomics--prospects for new interventions.

Science.gov (United States)

Ansell, Brendan R E; Schnyder, Manuela; Deplazes, Peter; Korhonen, Pasi K; Young, Neil D; Hall, Ross S; Mangiola, Stefano; Boag, Peter R; Hofmann, Andreas; Sternberg, Paul W; Jex, Aaron R; Gasser, Robin B

2013-12-01

Angiostrongylus vasorum is a metastrongyloid nematode of dogs and other canids of major clinical importance in many countries. In order to gain first insights into the molecular biology of this worm, we conducted the first large-scale exploration of its transcriptome, and predicted essential molecules linked to metabolic and biological processes as well as host immune responses. We also predicted and prioritized drug targets and drug candidates. Following Illumina sequencing (RNA-seq), 52.3 million sequence reads representing adult A. vasorum were assembled and annotated. The assembly yielded 20,033 contigs, which encoded proteins with 11,505 homologues in Caenorhabditis elegans, and additional 2252 homologues in various other parasitic helminths for which curated data sets were publicly available. Functional annotation was achieved for 11,752 (58.6%) proteins predicted for A. vasorum, including peptidases (4.5%) and peptidase inhibitors (1.6%), protein kinases (1.7%), G protein-coupled receptors (GPCRs) (1.5%) and phosphatases (1.2%). Contigs encoding excretory/secretory and immuno-modulatory proteins represented some of the most highly transcribed molecules, and encoded enzymes that digest haemoglobin were conserved between A. vasorum and other blood-feeding nematodes. Using an essentiality-based approach, drug targets, including neurotransmitter receptors, an important chemosensory ion channel and cysteine proteinase-3 were predicted in A. vasorum, as were associated small molecular inhibitors/activators. Future transcriptomic analyses of all developmental stages of A. vasorum should facilitate deep explorations of the molecular biology of this important parasitic nematode and support the sequencing of its genome. These advances will provide a foundation for exploring immuno-molecular aspects of angiostrongylosis and have the potential to underpin the discovery of new methods of intervention. © 2013.

The impact of advances in human molecular biology on radiation genetic risk estimation in man

International Nuclear Information System (INIS)

Sankaranarayanan, K.

1996-01-01

This paper provides an overview of the conceptual framework, the data base, methods and assumptions used thus far to assess the genetic risks of exposure of human populations to ionising radiation. These are then re-examined in the contemporary context of the rapidly expanding knowledge of the molecular biology of human mendelian diseases. This re-examination reveals that (i) many of the assumptions used thus far in radiation genetic risk estimation may not be fully valid and (ii) the current genetic risk estimates are probably conservative, but provide an adequate margin of safety for radiological protection. The view is expressed that further advances in the field of genetic risk estimation will be largely driven by advances in the molecular biology of human genetic diseases. (author). 37 refs., 5 tabs

Structural Molecular Biology-A Personal Reflection on the Occasion of John Kendrew's 100th Birthday.

Science.gov (United States)

Cramer, Patrick

2017-08-18

Here, I discuss the development and future of structural molecular biology, concentrating on the eukaryotic transcription machinery and reflecting on John Kendrew's legacy from a personal perspective. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterization of microbial communities in pest colonized books by molecular biology tools

OpenAIRE

Franco Palla

2011-01-01

This work presents the identification of bacteria and fungi colonies in insect infesting books, by cultural-independent methodologies based on molecular biology techniques. Microbial genomic DNA extraction, in vitro amplification of specific target sequences by polymerase chain reactions (PCR), sequencing and sequence analysis were performed. These procedures minimized the samples amount, optimized the diagnostic studies on bacteria and fungi colonization and allowed the identification of man...

Molecular and Biological Analysis of Potato virus M (PVM) Isolates from the Czech Republic

Czech Academy of Sciences Publication Activity Database

Plchová, Helena; Vaculík, Petr; Čeřovská, Noemi; Moravec, Tomáš; Dědič, P.

2015-01-01

Roč. 163, 11-12 (2015), s. 1031-1035 ISSN 0931-1785 R&D Projects: GA MŠk 1M06030 Institutional support: RVO:61389030 Keywords : Czech Republic * phylogeny * Potato virus M Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.945, year: 2015

Proceedings of the 3. international symposium on applied microbiology and molecular biology in oil systems: ISMOS 3

Energy Technology Data Exchange (ETDEWEB)

Rooijen, Gijs van; Caffrey, Sean M. [Genome Alberta (Canada); Lund Skovhus, Torben [DTI Oil and Gas (Denmark); Whitby, Corinne [University of Essex (United Kingdom)

2011-07-01

The 3rd international symposium on applied microbiology and molecular biology in oil systems was held in Calgary, Alberta, Canada, from June 13th to June 15th, 2011. This conference, organized by ISMOS TSC, gathered experts to discuss the application of microbial and molecular biology in the hydrocarbon sector. The conference was attended by key players from the oil and gas industry and provided them with the opportunity to learn about some of the latest technologies in areas such as the application of molecular microbiological methods for oil field systems, biodegradation of hydrocarbons in oil production, biofuels and downstream petroleum microbiology and challenges in biofuels and oil sands developments, and to network with their peers and share their expertise. 17 of the 31 papers presented during this conference have been catalogued separately for inclusion in this database.

Molecular biology of hyperthermophilic Archaea.

Science.gov (United States)

van der Oost, J; Ciaramella, M; Moracci, M; Pisani, F M; Rossi, M; de Vos, W M

1998-01-01

The sequences of a number of archaeal genomes have recently been completed, and many more are expected shortly. Consequently, the research of Archaea in general and hyperthermophiles in particular has entered a new phase, with many exciting discoveries to be expected. The wealth of sequence information has already led, and will continue to lead to the identification of many enzymes with unique properties, some of which have potential for industrial applications. Subsequent functional genomics will help reveal fundamental matters such as details concerning the genetic, biochemical and physiological adaptation of extremophiles, and hence give insight into their genomic evolution, polypeptide structure-function relations, and metabolic regulation. In order to optimally exploit many unique features that are now emerging, the development of genetic systems for hyperthermophilic Archaea is an absolute requirement. Such systems would allow the application of this class of Archaea as so-called "cell factories": (i) expression of certain archaeal enzymes for which no suitable conventional (mesophilic bacterial or eukaryal) systems are available, (ii) selection for thermostable variants of potentially interesting enzymes from mesophilic origin, and (iii) the development of in vivo production systems by metabolic engineering. An overview is given of recent insight in the molecular biology of hyperthermophilic Archaea, as well as of a number of promising developments that should result in the generation of suitable genetic systems in the near future.

Molecularly Imprinted Polymers for 5-Fluorouracil Release in Biological Fluids

Directory of Open Access Journals (Sweden)

Franco Alhaique

2007-04-01

Full Text Available The aim of this work was to investigate the possibility of employing Molecularly Imprinted Polymers (MIPs as a controlled release device for 5-fluorouracil (5-FU in biological fluids, especially gastrointestinal ones, compared to Non Imprinted Polymers (NIPs. MIPs were synthesized using methacrylic acid (MAA as functional monomer and ethylene glycol dimethacrylate (EGDMA as crosslinking agent. The capacity of the polymer to recognize and to bind the template selectively in both organic and aqueous media was evaluated. An in vitro release study was performed both in gastrointestinal and in plasma simulating fluids. The imprinted polymers bound much more 5-Fu than the corresponding non-imprinted ones and showed a controlled/sustained drug release, with MIPs release rate being indeed much more sustained than that obtained from NIPs. These polymers represent a potential valid system for drug delivery and this study indicates that the selective binding characteristic of molecularly imprinted polymers is promising for the preparation of novel controlled release drug dosage form.

MAGNETIC TWEEZERS FOR THE STUDY OF DNA TRACKING MOTORS

Science.gov (United States)

Manosas, Maria; Meglio, Adrien; Spiering, Michelle M.; Ding, Fangyuan; Benkovic, Stephen J.; Barre, François-Xavier; Saleh, Omar A.; Allemand, Jean François; Bensimon, David; Croquette, Vincent

2011-01-01

Single-molecule manipulation methods have opened a new vista on the study of molecular motors. Here we describe the use of magnetic traps for the investigation of the mechanism of DNA based motors, in particular helicases and translocases. PMID:20627163

Review and application of group theory to molecular systems biology.

Science.gov (United States)

Rietman, Edward A; Karp, Robert L; Tuszynski, Jack A

2011-06-22

In this paper we provide a review of selected mathematical ideas that can help us better understand the boundary between living and non-living systems. We focus on group theory and abstract algebra applied to molecular systems biology. Throughout this paper we briefly describe possible open problems. In connection with the genetic code we propose that it may be possible to use perturbation theory to explore the adjacent possibilities in the 64-dimensional space-time manifold of the evolving genome. With regards to algebraic graph theory, there are several minor open problems we discuss. In relation to network dynamics and groupoid formalism we suggest that the network graph might not be the main focus for understanding the phenotype but rather the phase space of the network dynamics. We show a simple case of a C6 network and its phase space network. We envision that the molecular network of a cell is actually a complex network of hypercycles and feedback circuits that could be better represented in a higher-dimensional space. We conjecture that targeting nodes in the molecular network that have key roles in the phase space, as revealed by analysis of the automorphism decomposition, might be a better way to drug discovery and treatment of cancer.

The Design of a Molecular Assembly Line Based on Biological Molecules

Science.gov (United States)

2003-06-01

parenthesis in figure 1.8 is a bi-stable toggle switch. Introduction: Molecular assembly lines O=P-O- O O HOH H0P-0- O -O- 4 Polymerase HO H--- O HHO ...sample. Therefore, the samples are self-consistent. From here on, the calculated temperature based on FAM emission MNSowmm" RF Biology: Results and...irradiation for one hour. Figure 2.11 shows the fluorescence spectra of FAM emission (4 scans averaged over 200 seconds) in a 300MHz field. The increased

Studying Environmental Influence on Motor Development in Children

Science.gov (United States)

Gabbard, Carl; Krebs, Ruy

2012-01-01

There is a good argument that in order to truly understand the influences that shape child motor development, one must consider environmental influences that reflect the multilevel ecological contexts that interact with the changing biological characteristics of the child. Although there are theories typically associated with motor development…

Parallel computation with molecular-motor-propelled agents in nanofabricated networks.

Science.gov (United States)

Nicolau, Dan V; Lard, Mercy; Korten, Till; van Delft, Falco C M J M; Persson, Malin; Bengtsson, Elina; Månsson, Alf; Diez, Stefan; Linke, Heiner; Nicolau, Dan V

2016-03-08

The combinatorial nature of many important mathematical problems, including nondeterministic-polynomial-time (NP)-complete problems, places a severe limitation on the problem size that can be solved with conventional, sequentially operating electronic computers. There have been significant efforts in conceiving parallel-computation approaches in the past, for example: DNA computation, quantum computation, and microfluidics-based computation. However, these approaches have not proven, so far, to be scalable and practical from a fabrication and operational perspective. Here, we report the foundations of an alternative parallel-computation system in which a given combinatorial problem is encoded into a graphical, modular network that is embedded in a nanofabricated planar device. Exploring the network in a parallel fashion using a large number of independent, molecular-motor-propelled agents then solves the mathematical problem. This approach uses orders of magnitude less energy than conventional computers, thus addressing issues related to power consumption and heat dissipation. We provide a proof-of-concept demonstration of such a device by solving, in a parallel fashion, the small instance {2, 5, 9} of the subset sum problem, which is a benchmark NP-complete problem. Finally, we discuss the technical advances necessary to make our system scalable with presently available technology.

The Analysis of Certain Differences in Motor Skills of Sedentary Male Children in the 9-14 Age Group Based on the Biological Maturity

Science.gov (United States)

Bayraktar, Isik; Yaman, Nigar; Zorba, Erdal; Yaman, Metin; Günay, Mehmet

2016-01-01

The aim of this study consists of the analysis of certain differences in motor skills of male children who are sedentary and in the age group of 9-14, in relation to the biological maturity. 522 sedentary male children from various parts of Turkey participated in this study. Body height and body weight measurements were taken from the participants…

[Molecular biology of renal cancer: bases for genetic directed therapy in advanced disease].

Science.gov (United States)

Maroto Rey, José Pablo; Cillán Narvaez, Elena

2013-06-01

There has been expansion of therapeutic options in the management of metastatic renal cell carcinoma due to a better knowledge of the molecular biology of kidney cancers. There are different tumors grouped under the term renal cell carcinoma, being clear cell cancer the most frequent and accounting for 80% of kidney tumors. Mutations in the Von Hippel-Lindau gene can be identified in up to 80% of sporadic clear cell cancer, linking a genetically inheritable disease where vascular tumors are frequent, with renal cell cancer. Other histologic types present specific alterations in molecular pathways, like c-MET in papillary type I tumors, and Fumarase Hydratase in papillary type II tumors. Identification of the molecular alteration for a specific tumor may offer an opportunity for treatment selection based on biomarkers, and, in the future, for developing an engineering designed genetic treatment.

Embryology meets molecular biology: Deciphering the apical ectodermal ridge.

Science.gov (United States)

Verheyden, Jamie M; Sun, Xin

2017-09-15

More than sixty years ago, while studying feather tracks on the shoulder of the chick embryo, Dr. John Saunders used Nile Blue dye to stain the tissue. There, he noticed a darkly stained line of cells that neatly rims the tip of the growing limb bud. Rather than ignoring this observation, he followed it up by removing this tissue and found that it led to a striking truncation of the limb skeletons. This landmark experiment marks the serendipitous discovery of the apical ectodermal ridge (AER), the quintessential embryonic structure that drives the outgrowth of the limb. Dr. Saunders continued to lead the limb field for the next fifty years, not just through his own work, but also by inspiring the next generation of researchers through his infectious love of science. Together, he and those who followed ushered in the discovery of fibroblast growth factor (FGF) as the AER molecule. The seamless marriage of embryology and molecular biology that led to the decoding of the AER serves as a shining example of how discoveries are made for the rest of the developmental biology field. Copyright © 2017 Elsevier Inc. All rights reserved.

Nacimiento y evolución de la bioquímica y la biología molecular en la Comunidad Valenciana (1963-2013)

OpenAIRE

CARBONELL GISBERT, JUAN

2013-01-01

Carbonell Gisbert, J. (2013). Nacimiento y evolución de la bioquímica y la biología molecular en la Comunidad Valenciana (1963-2013). SEBBM. Revista de la Sociedad Española de Bioquímica y Biología Molecular. 178:36-38. http://hdl.handle.net/10251/98796 S 36 38 178

An RNA Domain Imparts Specificity and Selectivity to a Viral DNA Packaging Motor

Science.gov (United States)

Zhao, Wei; Jardine, Paul J.

2015-01-01

ABSTRACT During assembly, double-stranded DNA viruses, including bacteriophages and herpesviruses, utilize a powerful molecular motor to package their genomic DNA into a preformed viral capsid. An integral component of the packaging motor in the Bacillus subtilis bacteriophage ϕ29 is a viral genome-encoded pentameric ring of RNA (prohead RNA [pRNA]). pRNA is a 174-base transcript comprised of two domains, domains I and II. Early studies initially isolated a 120-base form (domain I only) that retains high biological activity in vitro; hence, no function could be assigned to domain II. Here we define a role for this domain in the packaging process. DNA packaging using restriction digests of ϕ29 DNA showed that motors with the 174-base pRNA supported the correct polarity of DNA packaging, selectively packaging the DNA left end. In contrast, motors containing the 120-base pRNA had compromised specificity, packaging both left- and right-end fragments. The presence of domain II also provides selectivity in competition assays with genomes from related phages. Furthermore, motors with the 174-base pRNA were restrictive, in that they packaged only one DNA fragment into the head, whereas motors with the 120-base pRNA packaged several fragments into the head, indicating multiple initiation events. These results show that domain II imparts specificity and stringency to the motor during the packaging initiation events that precede DNA translocation. Heteromeric rings of pRNA demonstrated that one or two copies of domain II were sufficient to impart this selectivity/stringency. Although ϕ29 differs from other double-stranded DNA phages in having an RNA motor component, the function provided by pRNA is carried on the motor protein components in other phages. IMPORTANCE During virus assembly, genome packaging involves the delivery of newly synthesized viral nucleic acid into a protein shell. In the double-stranded DNA phages and herpesviruses, this is accomplished by a powerful

An RNA Domain Imparts Specificity and Selectivity to a Viral DNA Packaging Motor.

Science.gov (United States)

Zhao, Wei; Jardine, Paul J; Grimes, Shelley

2015-12-01

During assembly, double-stranded DNA viruses, including bacteriophages and herpesviruses, utilize a powerful molecular motor to package their genomic DNA into a preformed viral capsid. An integral component of the packaging motor in the Bacillus subtilis bacteriophage ϕ29 is a viral genome-encoded pentameric ring of RNA (prohead RNA [pRNA]). pRNA is a 174-base transcript comprised of two domains, domains I and II. Early studies initially isolated a 120-base form (domain I only) that retains high biological activity in vitro; hence, no function could be assigned to domain II. Here we define a role for this domain in the packaging process. DNA packaging using restriction digests of ϕ29 DNA showed that motors with the 174-base pRNA supported the correct polarity of DNA packaging, selectively packaging the DNA left end. In contrast, motors containing the 120-base pRNA had compromised specificity, packaging both left- and right-end fragments. The presence of domain II also provides selectivity in competition assays with genomes from related phages. Furthermore, motors with the 174-base pRNA were restrictive, in that they packaged only one DNA fragment into the head, whereas motors with the 120-base pRNA packaged several fragments into the head, indicating multiple initiation events. These results show that domain II imparts specificity and stringency to the motor during the packaging initiation events that precede DNA translocation. Heteromeric rings of pRNA demonstrated that one or two copies of domain II were sufficient to impart this selectivity/stringency. Although ϕ29 differs from other double-stranded DNA phages in having an RNA motor component, the function provided by pRNA is carried on the motor protein components in other phages. During virus assembly, genome packaging involves the delivery of newly synthesized viral nucleic acid into a protein shell. In the double-stranded DNA phages and herpesviruses, this is accomplished by a powerful molecular motor

Using electrical and optical tweezers to facilitate studies of molecular motors.

Science.gov (United States)

Arsenault, Mark E; Sun, Yujie; Bau, Haim H; Goldman, Yale E

2009-06-28

Dielectrophoresis was used to stretch and suspend actin filaments across a trench etched between two electrodes patterned on a glass slide. Optical tweezers were used to bring a motor protein-coated bead into close proximity to a pre-selected, suspended actin filament, facilitating the attachment of the myosin-coated bead to the filament. The clearance beneath the filament allowed the bead to move freely along and around its filamentous track, unhindered by solid surfaces. Using defocused images, the three-dimensional position of the bead was tracked as a function of time to obtain its trajectory. Experiments were carried out with myosin V and myosin X. Both motor proteins followed left-handed helical paths with the myosin X motor exhibiting a shorter pitch than the myosin V. The combined use of electrostatic and optical tweezers facilitates the preparation of motility assays with suspended tracks. Variants of this technique will enable higher complexity experiments in vitro to better understand the behavior of motors in cells.

What Skills Should Students of Undergraduate Biochemistry and Molecular Biology Programs Have upon Graduation?

Science.gov (United States)

White, Harold B.; Benore, Marilee A.; Sumter, Takita F.; Caldwell, Benjamin D.; Bell, Ellis

2013-01-01

Biochemistry and molecular biology (BMB) students should demonstrate proficiency in the foundational concepts of the discipline and possess the skills needed to practice as professionals. To ascertain the skills that should be required, groups of BMB educators met in several focused workshops to discuss the expectations with the ultimate goal of…

Program and abstracts of the 25. Annual meeting of the Brazilian Society on Biochemistry and Molecular Biology

International Nuclear Information System (INIS)

1996-01-01

The meeting was about biochemistry and molecular biology.In this meeting it was also discussed the following subjects: biotechnology, metabolism, enzymes, proteins, immunology, drugs and others related topics

Molecular building blocks and their architecture in biologically/environmentally compatible soft matter chemical machinery.

Science.gov (United States)

Toyota, Taro; Banno, Taisuke; Nitta, Sachiko; Takinoue, Masahiro; Nomoto, Tomonori; Natsume, Yuno; Matsumura, Shuichi; Fujinami, Masanori

2014-01-01

This review briefly summarizes recent developments in the construction of biologically/environmentally compatible chemical machinery composed of soft matter. Since environmental and living systems are open systems, chemical machinery must continuously fulfill its functions not only through the influx and generation of molecules but also via the degradation and dissipation of molecules. If the degradation or dissipation of soft matter molecular building blocks and biomaterial molecules/polymers can be achieved, soft matter particles composed of them can be used to realize chemical machinery such as selfpropelled droplets, drug delivery carriers, tissue regeneration scaffolds, protocell models, cell-/tissuemarkers, and molecular computing systems.

Third Jesús Culebras Lecture: Molecular Biology and Clinical Nutrition; ¿where do we stand and where do we go?

OpenAIRE

Gil, Ángel

2013-01-01

Nutrition plays a fundamental role in the maintenance of health and the treatment of disease, and serves as the crossroads for many disciplines. Biochemistry and Molecular Biology represents a key brand of science to ascertain the mechanism of action of nutrients and other food bioactive compounds in health and disease. The aim of the present Jesús M. Culebras lecture is to consider the future of the relationships between Molecular Biology and Clinical Nutrition and to discuss the use of mole...

Molecular and cellular biology of cerebral arteriovenous malformations: a review of current concepts and future trends in treatment.

Science.gov (United States)

Rangel-Castilla, Leonardo; Russin, Jonathan J; Martinez-Del-Campo, Eduardo; Soriano-Baron, Hector; Spetzler, Robert F; Nakaji, Peter

2014-09-01

Arteriovenous malformations (AVMs) are classically described as congenital static lesions. However, in addition to rupturing, AVMs can undergo growth, remodeling, and regression. These phenomena are directly related to cellular, molecular, and physiological processes. Understanding these relationships is essential to direct future diagnostic and therapeutic strategies. The authors performed a search of the contemporary literature to review current information regarding the molecular and cellular biology of AVMs and how this biology will impact their potential future management. A PubMed search was performed using the key words "genetic," "molecular," "brain," "cerebral," "arteriovenous," "malformation," "rupture," "management," "embolization," and "radiosurgery." Only English-language papers were considered. The reference lists of all papers selected for full-text assessment were reviewed. Current concepts in genetic polymorphisms, growth factors, angiopoietins, apoptosis, endothelial cells, pathophysiology, clinical syndromes, medical treatment (including tetracycline and microRNA-18a), radiation therapy, endovascular embolization, and surgical treatment as they apply to AVMs are discussed. Understanding the complex cellular biology, physiology, hemodynamics, and flow-related phenomena of AVMs is critical for defining and predicting their behavior, developing novel drug treatments, and improving endovascular and surgical therapies.

Characterization of microbial communities in pest colonized books by molecular biology tools

Directory of Open Access Journals (Sweden)

Franco Palla

2011-08-01

Full Text Available This work presents the identification of bacteria and fungi colonies in insect infesting books, by cultural-independent methodologies based on molecular biology techniques. Microbial genomic DNA extraction, in vitro amplification of specific target sequences by polymerase chain reactions (PCR, sequencing and sequence analysis were performed. These procedures minimized the samples amount, optimized the diagnostic studies on bacteria and fungi colonization and allowed the identification of many species also in complex microbial consortia. The molecular techniques for sure accomplish and integrate the microbiological standard methods (in vitro culture and morphological analyses (OM, SEM, CLSM, in order to understand the role of microorganisms in bio-deterioration of cultural assets. This monitoring is also indispensable to shed light on the risk for visitors and/or professionals to contract potential illnesses within indoor environments.

Ablation of the Ferroptosis Inhibitor Glutathione Peroxidase 4 in Neurons Results in Rapid Motor Neuron Degeneration and Paralysis.

Science.gov (United States)

Chen, Liuji; Hambright, William Sealy; Na, Ren; Ran, Qitao

2015-11-20

Glutathione peroxidase 4 (GPX4), an antioxidant defense enzyme active in repairing oxidative damage to lipids, is a key inhibitor of ferroptosis, a non-apoptotic form of cell death involving lipid reactive oxygen species. Here we show that GPX4 is essential for motor neuron health and survival in vivo. Conditional ablation of Gpx4 in neurons of adult mice resulted in rapid onset and progression of paralysis and death. Pathological inspection revealed that the paralyzed mice had a dramatic degeneration of motor neurons in the spinal cord but had no overt neuron degeneration in the cerebral cortex. Consistent with the role of GPX4 as a ferroptosis inhibitor, spinal motor neuron degeneration induced by Gpx4 ablation exhibited features of ferroptosis, including no caspase-3 activation, no TUNEL staining, activation of ERKs, and elevated spinal inflammation. Supplementation with vitamin E, another inhibitor of ferroptosis, delayed the onset of paralysis and death induced by Gpx4 ablation. Also, lipid peroxidation and mitochondrial dysfunction appeared to be involved in ferroptosis of motor neurons induced by Gpx4 ablation. Taken together, the dramatic motor neuron degeneration and paralysis induced by Gpx4 ablation suggest that ferroptosis inhibition by GPX4 is essential for motor neuron health and survival in vivo. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.