Protein function imaging

Various optical detection methods have been used to measure pH in vivo. Fluorescence ratio imaging microscopy using an inverted microscope was used to determine intracellular pH in tumor cells [5], NMR spectroscopy was used to continuously monitor temperature-induced pH changes in fish to study the role of intracellular pH in the maintenance of protein function [27], Additionally, NMR spectroscopy was used to map in-vivo extracellular pH in rat brain gliomas [3], Electron spin resonance (ESR), which is operated at a lower resonance, has been adapted for in-vivo pH measurements because it provides a sufficient RF penetration for deep body organs [28], The non-destructive determination of tissue pH using near-infrared diffuse reflectance spectroscopy (NIRS) has been employed for pH measurements in the muscle during... 

Over the next few years, functional imaging has the potential to completely revolutionize our understanding of the mind. Twentieth-century chemistry and physics transformed biology into molecular biology enzymes and proteins became understood as big molecules instead of black boxes, and the molecular basis of life processes was developed. Scientists are now on the threshold of acquiring this same level of understanding of processes in cells and organs. 

Mirror-Image Proteins As noted in Chapter 3, The amino acid residues in protein molecules are exclusively L stereoisomers. It is not clear whether this selectivity is necessary for proper protein function or is an accident of evolution. To explore this question, Milton and colleagues (1992) published a study of an enzyme made entirely of D stereoisomers. The enzyme they chose was HIV protease, a proteolytic enzyme made by HIV that converts inactive viral pre-proteins to their active forms. 

Kumar U, Shete A, Harle AS, Kasyutich O, Schwarzacher W, Pundle A, Poddar P. (2008) Extracellular bacterial synthesis of protein functionalized ferromagnetic C03O4 nanocrystals and imaging of... 

Sharma V, Luker GD and Piwnica-Worms D. Molecular imaging of gene expression and protein function in vivo with PET and SPECT. JMagn Reson Imaging 2002 16 336-351. Shen DW, Fojo A, Chin JE, Roninson IB, Richer N, Pastan I et al. Human multidrug-resistant cell lines increased mdrl expression can precede gene amplification. Science 1986 232 643-645. 

Fig. C11.5 Three examples of knots in proteins, including the very complex knot 5i in a protein called human ubiquitin hydrolase (the rightmost image). In each case, a simple model of sticks shows the same knot as in the protein. To help the eye, each chain is colored in rainbow colors from one end to the other. The figure is reproduced, with kind permission by the authors, from the paper P. Virnau, L. Mirny and M. Kardar, Intricate Knots in Proteins Function and Evolution, PLoS Computational Biology, v. 2, pp. 1074-1079, 2006.

Sharma V, Luker GD, Piwnica-Worms D. Molecular imaging of gene expression and protein function in vivo with PET and SPECT. J Magn Res Imaging 2002 16 336-351. 

Single molecule analysis can reveal the mechanistic details of protein function, with AFM and FRET imaging being the favored tools in such investigations. FRET imaging allows observation of biomolecular... 

After the scanning process, the protein colour image is denoted as X. Then, the image is separated into R (red), G (green), and B (blue) channels. We named them as function X/iJ), Xg(iJ), and Xb(i,j), respectively. 

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