Protein specificity

The farnesylation and subsequent processing of the Ras protein. Following farnesylation by the FTase, the carboxy-terminal VLS peptide is removed by a prenyl protein-specific endoprotease (PPSEP) in the ER, and then a prenylprotein-specific methyltransferase (PPSMT) donates a methyl group from S-adenosylmethionine (SAM) to the carboxy-terminal S-farnesylated cysteine. Einally, palmitates are added to cysteine residues near the C-terminus of the protein. 

The genes responsible for encoding the proteins specifically involved in exopolysaccharide synthesis are dustered in one large operon. The genes encoding the proteins for sugar nucleotide phosphates, which are not necessarily spedfically used for exopolysaccharide synthesis, also tend to be dustered. 

Microelectronic circuits for communications. Controlled permeability films for drug delivery systems. Protein-specific sensors for the monitoring of biochemical processes. Catalysts for the production of fuels and chemicals. Optical coatings for window glass. Electrodes for batteries and fuel cells. Corrosion-resistant coatings for the protection of metals and ceramics. Surface active agents, or surfactants, for use in tertiary oil recovery and the production of polymers, paper, textiles, agricultural chemicals, and cement. 

The spectrum recorded at 230 K was discarded in the fit procedure because above 200 K the effective thickness decreases drastically because of a significant softening of protein-specific modes [16]. From the simultaneous fit of the spectra in the temperature range 3.2-200 K, the Debye temperature was determined as do = 215 K. AEq proved to be a temperature-dependent quantity, which is discussed later (see Sect. 9.4.2). 

Nicoletti, A., D. J. Wong et al. (1995). Molecular characterization of the human gene encoding an abundant 61 kDa protein specific to the retinal pigment epithelium. Hum. Mol. Genet. 4(4) 641-649. 

Figure 14 6 Silver-stained SDS-PAGE gel of PatA binding proteins. Lane 1, sample 1 nonspecific proteins captured by the streptavidin-agarose resin Lane 2, sample 2 proteins affinity captured by the presence of B-Pat A Lane 3, sample 3 affinity capture of target proteins was blocked by prior addition of free PatA before incubation with B-PatA. The two arrows point to two proteins specifically detected in sample 2 versus sample 1, which were also lost due to competition in sample 3, with apparent molecular weights of 38 and 48 kDa.

Various methods have been used to examine the composition of proteins adsorbed to SAMs. Overall adsorption patterns can be examined with sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) [50, 76, 77]. Absorbed proteins are eluted from the surface with surfactant (SDS), and then separated by electrophoresis. The proteins of interest are examined by western blotting [50, 76, 77]. Protein-specific antibodies can be used to detect proteins of... 

The following is a generalized protocol for the activation of a protein with sulfo-SMCC with subsequent conjugation to a sulfhydryl-containing second molecule or protein. Specific examples of the use of this crosslinker to make antibody-enzyme or hapten-carrier conjugates may be found in Chapter 20, Section 1.1 and Chapter 19, Section 5, respectively. 

Neurotransmitter transporters There are probably at least five types of transport protein specific for glutamate, acetylcholine, catecholamines, glycine/GABA and ATP. The type of transporter contributes to determining the transmitter specificity of a synapse. 

Albert, P. R. and Robillard, L. G protein specificity traffic direction required. Cell. Signal. 14 407-418, 2002. 

Although the occurrence of six conserved cysteine residues, the spacing patterns of these residues, and possibly the pattern of disulfide structures are hallmarks of OBPs, the six-cysteine criterion alone is not sufficient to classify a certain protein as an olfactory protein [ 16]. It is important to demonstrate that an OBP is expressed only (or predominantly) in olfactory tissues. Evidence for their ability to bind odorants is also desirable, but not sine qua non. One of these criteria alone would not be enough to define a given protein as an OBP. For example, bovine serum albumin (BSA) binds to insect pheromones (Leal, unpublished data) and yet it is not an OBP because it not expressed in insect olfactory tissues. Conversely, a protein specific to antennae is not necessarily an OBP. There are other proteins that may be expressed in antennae but not in control tissues. Non-OBPs specifically accumulated in insect antennae have been previously detected (Ishida and Leal, unpublished data). Also, a glu-tathione-S-transferase has been reported to be expressed specifically in antennae of M. sexta [52]. 

Conceptually, we can separate environmental effects (fcnr) and specific quenching mechanisms (k ), where kpq is due to the presence of a quenching moiety within the protein. Specific quenching effects of externally added quenchers are discussed in Section 3.3.5. 

Dobbs LG, Gonzalez RF, Allen L, Froh DK (1999) HTI56, an integral membrane protein specific to human alveolar type I cells. J Histochem Cytochem 47 129-137... 

The direct absorbance methods require only a protein-specific extinction coefficient to deliver an accurate protein concentration. These methods typically require minutes to perform and require only a spectrophotometer and a good quantitative... 

Finally, there are custom two-step quantitation methods such as chromatography or ELISA that require a capture step for isolating the protein and then a quantitation step based on a standard curve of the purified target protein. The preliminary capture step may also concentrate the protein for increased sensitivity. These techniques are typically not available in a commercial kit form and may require extensive method development. They are more labor intensive and complex than the colorimetric or absorbance-based assays. In addition, recovery of the protein from and reproducibility of the capture step complicate validation. Despite these disadvantages, the custom two-step quantitation methods are essential in situations requiring protein specificity. 

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