Alanine signal

Abbreviations w, weak m, medium s, strong , the spectra were too ill-defined in the regions of interest for a decision to be made as to the presence or not of an alanine signal. 

The sensitivity of ESR spectroscopy is such that, in ancient bone, what we see may be a relict protein structure far beyond the limits of extractive techniques. The stability of the signal and the correspondence between ancient and modem bone suggests that the signal has not been caused by recent intrusions or a free amino acid. The alanine signal may be produced by an alanine moiety on the end of a protein chain that is denatured by the y-irradiation. Presumably, heating the modem samples accelerates some chemical reaction that would otherwise take many years to complete this... 

Alanine signal generation in bone, 367 heat response, 357 signal production threshold, 367 Zhoukoudian bone, 374 Albumin, trapped, 399 Albumin in body fluids, 15 Albumin in tissue extracts and body fluids, 400 ... 

The behaviour of the mutant enzymes where, for example, histidine-152 has been changed to alanine is compared with that of wild type enzymes.60 The 31P NMR chemical shift values and signal width for H152A mutant enzyme have shown the presence of two conformers open and closed forms of the enzyme that interconvert slowly on the NMR time scale. The tightness of the binding of the cofactor to the protein surface and its protonation state have been also discussed for intermediate Schiff bases in different steps of the catalytic cycle (Table 1). 

Evidence accumulating from various laboratories has clearly demonstrated that lithium, at therapeutically relevant concentrations, exerts significant effects on the PKC signaling cascade. Current data suggest that chronic lithium attenuates PKC activity, and down-regulates the expression of PKC isozymes V in the frontal cortex and hippocampus [79, 80], Chronic lithium has also been demonstrated to dramatically reduce the hippocampal levels of a major PKC substrate, myristoylated-alanine-rich C kinase substrate (MARCKS), which has been implicated in regulating long-term neuroplastic events. 

Fig. 15. H-Ras mGTP shows a transient increase in fluorescence signal when mixed with the catalytic domain of the Ras-GAP neurofibromin (NF1). When wildtype NF1 is applied (gray trace) a decrease in signal follows, indicating the hydrolysis of mant-GTP. A NF1 mutant bearing an alanine at the position of the catalytic arginine residue (black trace) can only bind to Ras mant-GTP (increase) but cannot induce mant-GTP hydrolysis (no decrease). Figure kindly committed by Reza Ahmadian...

The substrate specificity of the type I signal peptidases is known as the ( — 3, —1) rule observed at the c-region of signal peptides (von Heijne, 1984 Jain et al., 1994), where the residues at positions —3 and -1 from the cleavage site (i.e., cleavage occurs at the peptide bond between —1/ + 1 positions) are usually small (and neutral) residues, such as alanine. Recently, the x-ray crystallographic structure of the signal... 

The second family of secreted proteins that is covalently lipidated is the family of Wnt proteins. They are also involved in numerous processes like proliferation of stem cells, specification of the neural crest, and the expanding of specific cell types. The correct regulation of this pathway is important for animal development. Willert and coworkers were the first to isolate an active Wnt molecule. Mass spectroscopy studies carried out with the isolated protein revealed that cysteine 93 is palmitoylated. Mutating this amino acid to alanine led to almost complete loss of the signaling activity. Later in 2006, a second lipidation was found on a serine in Wnt3a. " In this case, the hydroxyl side chain is acylated with palmitoleic acid. This unsaturated fatty acid seems to be crucial for the progression of the protein through the secretory pathway. The attachment of two different lipid chains may therefore serve different functions. ... 

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