Biomolecular processes

Pyrene fluorophores are also used as probes. Derivatives of pyrene show /.max/ Xem 340/376 nm, e 4.3 x 104 M 1 cm-1, and environmental sensitivity, this fluorophore can be used to report on RNA folding [102]. Pyrene also displays a long-lived excited state (x > 100 ns), which allows for an excited pyrene molecule to associate with a pyrene in the ground state. The resulting eximer exhibits a red-shift in fluorescence intensity (A,em 490 nm). This characteristic can be used to study important biomolecular processes, such as protein conformation [103]. 

M. Barbara, A. Bonfiglio, and L. Raffo, A charge-modulated FET for detection of biomolecular processes conception, modelling, and simulation. IEEE Trans. Electron Devices 53, 158-166 (2006). 

X = 0, CH2, CHCOOH, C(COOH)2, NH, NCH3 N(CH2CH=CH2), N(CHs)2 Cl Bobrowski and Das published a series of papers on the transients in the pulse radiolysis of retinyl polyenes31-37, due to their importance in a variety of biomolecular processes. They studied32 the kinetics and mechanisms of protonation reaction. The protons were released by pulse radiolysis, on a nanosecond time scale, of 2-propanol air-saturated solutions containing, in addition to the retinyl polyenes, also 0.5 M acetone and 0.2 M CCI4. Within less than 300 ns, the electron beam pulse results in formation of HC1. The protonated products of retinyl polyenes were found to absorb optically with Xmax at the range of 475-585 nm and were measured by this absorption. They found that the protonation rate constants of polyene s Schiff bases depend on the polyene chain... 

The first four oligonucleotides given in the table are self-complementary, and they form full duplex structures in biomolecular processes that are the reverse of melting. The last two oligonucleotides are only partially self-complementary. However, they share a common self-complementary core with the previous two entries in the table. The common core of these four oligonucleotides is given in bold letters in the table. 

Electrophilic substitution in an aromatic series is a biomolecular process which involves displacement of a hydrogen atom bonded to the aromatic ring, acid or Lewis acid. 

In this review, we present NMR spectroscopic techniques currently used to study protein dynamics at various time scales. Instead scrutinizing each technique, we put emphasis on their fundamentals. On the other hand, we enumerate a number of NMR-derived parameters and discuss their relation and relevance to macromolecular motions. As a complement, we briefly describe several other techniques capable of capturing protein dynamics, as synthesis of different methods is the most fruitful way to understand biomolecular processes. 

Murray-Rust, P. In Computer Modelling of Biomolecular Processes Goodfellow, J. Moss, D. S., Eds. Ellis Horwood New York, 1992, p. 19. 

P. Murray-Rust, in Computer Modelling of Biomolecular Processes, J. M. Goodfellow and D. S. Moss., eds., Ellis Horwood, New York, 1992. 

J. J. Hopfield has proposed a so-called energy relay model [101], in which the ping-pong mechanism operates on two identical substrate molecules and releases two identical product molecules. The model introduces the novel idea of dynamic cooperativity by which biomolecular processes in living cells, such as DNA replication and protein biosynthesis, can achieve high fidelity. The model was developed as an alternative to the kinetic proofreading mechanism which we shall discuss in Chapter 5. 

Extension of laser investigations to further biomolecular processes will proceed parallel with an improved technological laser development. In particular, reliable, push-button tunable lasers in the UV providing tunable UV-radiation with sufficient intensity, will greatly enhance the field of applications. 

H-transfer reactions are of great interest because they play important roles in a variety of systems, from gas-phase combustion and atmospheric reactions of small molecules to complex catalytic and biomolecular processes. Many enzyme reactions involve proton or hydride transfer in the chemical step [26], and we know from experience with simpler reactions that multidimensional treatments of the tunneling process are essential for quantitative accuracy and sometimes even for qualitative understanding. 

Many molecular assemblies that play a fundamental role in biomolecular processes are sensitive to pressure. Thus pressure has a very strong effect on the association of the proteins in ribosome s, actin, microtubuli, bacterial flagellin and other macromolecular assemblies. Temperature may have a strong influence on the pressure effect as demonstrated in the case of microtubules [108], In some cases, very small pressures have an effect, visible with the optical microscope, on the shape and the behavior of living cells [109]. When the pressures are mild, the effects may be reversible. Studies on small living systems should teach us a lot on the effect of pressure on living matter. 

Chen E, Goldbeck R A and Kliger D S 1997 Nanosecond time-resolved spectroscopy of biomolecular processes Annu. 

These methods have been applied to studying various natural light-induced biomolecular processes such as photosynthesis and vision. With modem pulsed-laser techniques one can use light pulses as short as a few femtoseconds, or less, and this gives information about the very earliest stages of important photochemical reactions. 

Some dye molecules have a different x>Ka in the electronically excited state, so that they release or take up H ions when exposed to a flash of light. This can be used to bring about rapid pH changes in solution. Such pH-jump experiments can be used to follow the kinetics of biomolecular processes. Other kinds of photochemical reactions can be used to overcome mixing problems in rapid kinetic experiments. One example of this is the use of caged ATP compounds that only become available for enzyme reaction, for example, when exposed to an intense light flash. ... 

The further understanding of cellular and biomolecular processes has led to the engineering of stem cells into therapeutically valuable lineages and to the regeneration of organs and tissue structures. 

An understanding of electrostatic interactions is essential for the study of biomolecular processes. The structures of proteins and other biopolymers are being determined at an increasing rate through structural genomics and other... 

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