Inducer molecules

More than 30 years ago Jacob and Monod introduced the Escherichia coli lac operon as a model for gene regulation. The lac repressor molecule functions as a switch, regulated by inducer molecules, which controls the synthesis of enzymes necessary for E. coli to use lactose as an energy source. In the absence of lactose the repressor binds tightly to the operator DNA preventing the synthesis of these enzymes. Conversely when lactose is present, the repressor dissociates from the operator, allowing transcription of the operon. 

Ngo VN, Tang HL, Cyster JG. Epstein-Barr virus-induced molecule 1 ligand chemokine is expressed by dendritic cells in lymphoid tissues and strongly attracts naive T cells and activated B cells. J Exp Med 1998 188(1) 181—191. 

Of the five snRNAs, U2 and U6 interact with the reaction site (the 5 splice site and the branch point) in the first chemical step. These two snRNAs are known to anneal together to form a stable-based paired structure in the absence of proteins and in the presence of ions as shown in Fig. 13, with U2 acting as an inducer molecule that displaces the U4 (that is an antisense molecule that regulates the catalytic function of U6 RNA) from the initially formed U4-U6 duplex. The secondary (or higher ordered) structure of the U2-U6 complex consists of the active site of the spliceosome. Recent data suggests that these two snRNAs function as the catalytic domain of the spliceosome that catalyzes the first step of the splicing reaction [145]. 

Studies of pathogenic fungi suggested an explanation for the absence of inducer molecules in host root exudate. Quinones such as 2,6-DMBQ have been shown to be released by white rot fungi as terminal oxidation products of lignin model compounds (38). These findings substantiated previous reports (39-41) that laccases, phenol oxidases using 0 as the oxidant, are directly involved in... 

Internal diastereomers of the kind depicted in Figure 3 have two kinds of interaction between the chiral centers the total interaction and that part of the total interaction which is discriminatory. The latter we call the diastereotopic interaction, and it is only this part of the interaction that causes either Kx in Figure 3 to be displaced from unity or the activation energies of the diastereomeric transition states to be different. It follows that the object in asymmetric synthesis is to maximize the diastereotopic interaction. In the absence of a clear lock-and-key compatibility for the inducing molecule and the substrate, the stereochemical criteria for maximizing the diastereotopic interaction are not always obvious. For example, it is a commonly held view that an increase in the relative steric bulk of certain groups will increase discrimination. This may only increase the nondiscriminatory interaction unless such elaboration is directed at features of the substrate which control the discrimination. 

A. E. Morelli, A. T. Larregina, A. J. Smith, R. A. Dewey, T. D. Southgate, B. Ambar, A. Fontana, M. G. Castro, and P. R. Lowenstein, Neuronal and glial cell type-specific promoters within adenovirus recombinants restrict the expression of the apoptosis-inducing molecule Fas ligand to predetermined brain cell types, and abolish peripheral liver toxicity, J. Gen. Virol. 80 571 (1999). 

Considerable experimental evidence suggests that chemical cues are very important in substrate selection by larvae. In nature, chemical cues may interact with physical or hydrodynamic factors to induce larval settlement.5-7 Despite the evidence that chemical cues are extremely important for settling larvae, the complete chemical identity of the natural inducer molecules is known in very few cases.3-8-11 More commonly, partial chemical characterization has provided clues to the chemical identity of the natural inducers. These partially purified inducers are useful for studying the biology of larval settlement and metamorphosis.912-18... 

A relevant set of not experimentally infected individuals (control) is required for differential analysis by MALDI-TOF-MS or RP-HPLC in order to discriminate between immune-induced molecules and constitutively present substances (19). This is a prerequisite when no in vitro assays are used to select the bioactive peptides from the immune system of the model invertebrate investigated. 

I hc dispersion forces, however, possess different properties. As London has pointed out, if several molecules interact simultaneously with one another, each molecule will introduce into the other molecules a scries of coordinated periodic dipoles, which are in phase with the exciting dipoles. Each molecule thus produces a number of induced periodic dipoles each of which is always oriented so that it is attracted to the corresponding inducing molecule. The resulting simultaneous interaction of several molecules leads to the additive superposition of the forces of attraction of individual pairs of molecules. Thus, for example, if we have three molecules, the dispersion energy will be... 

Inducers. Molecules that cause an increase in a protein activity when added to cells. 

Following this molecular mass differential display, a series of 24 molecules (DIMs, for Drosophila immune-induced molecules) with molecular masses ranging from 1.5 to 10 kDa was induced experimentally. 

Fig. (5). Typical mass spectra from the Drosophila hemolymph (0.1 pL) collected from a single fly at 6h, 24h post challenge and from a control (unchallenged) fly. MALDI mass spectra were acquired with a sandwich sample preparation and a-cyano-4-hydroxycinnamic acid as matrix. Numbers (1-24) correspond to the Drosophila immune-induced molecules (DIMs).

Cebrian M, Yague E, Rincon M et al (1988) Triggering of T cell proliferation through AIM, an activation inducer molecule expressed on activated human lymphocytes. J Exp Med 168 1621-1637... 

In the following section, different types of branched molecules will be described and we are going to discuss the possibility to obtain an enhancement of TPA efficiency by inducing molecules interactions within considered TPA systems. 

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