Crosslinking reagents table

In recent years such antibodies have also been utilised to identify putative plant G polypeptides. In particular, initial efforts utilised antisera to the a<. peptide and identified polypeptides of Mr 33 kDa or 31 kDa [19]. Other workers used anti-Gs serum [69] which crossreacted with proteins of Mr 37 kDa and 50 kDa associated with microsomal membranes from Cucurbita pepo. Since then, antisera to a number of other G-protein subtypes, i.e. Gi , Gt , GAra , Go and Gq have been utilised with varying degrees of success [35,36,100,156,151). These data are summarised in Table 2. One problem that has arisen in some reports, is the omission of a control appropriate to the use of anti-peptide antibodies. With these reagents, artifactual cross reactions are frequently encountered, which may represent recognition of part of the peptide sequence, the crosslinking reagent or the carrier protein. An essential pre-requisite to assess fidelity of identification is the ability to block the cross reaction via preincubation of the antiserum with the synthetic peptide to which it was raised. 

Up to now the single source precursor route is mainly used for preparing polymers in the quaternary Si/B/N/C system, and only to a minor degree in the Si/B/N and Si/B/C systems. A synopsis of the reactions of the single source precursors with respective crosslinking reagents is included in Table 2. The most commonly used, and most versatile, procedure for synthesizing prece-... 

The first represents the direct interaction of polystyrene with, for example, 0.5 mol of monochlorodimethyl ether (MCDE) [230]. In this case, however, the reaction medium proves to be extremely dduted with respect to aU reacting components, including the crosslinking reagent and the catalyst (stannic tetrachloride), and completing the process requires approximately 100 h. Also, smaU traces of impurities in the large amount of the solvent can deactivate the catalyst. These factors result in poor reproducibdity of the reaction product, especiaUy at very low concentrations of about 0.05% (Table 8.1). 

The extent of sulfonation of 8% crosslinked styrene divinylbenzene co-polymer beads (Biorad Bio Bead SX 8) was investigated by comparing the surface composition after sulfonation of the beads using chlorosulfonic acid, sulfuric acid and fuming sulfuric (54). Each reagent was refluxed in methylene chloride for a similar period of time. A wide-scan spectrum indicates the presence of sulfur 2p and 2s electrons, indicative of sulfonation. The surface sulfur content was fairly similar in the surface region analyzed by XPS. The composition determined from beads sulfonated by the three methods is indicated in Table VI. 

The reagents in current use for protein crosslinking have one chemically reactive and one photochemically reactive arm, often connected by a cleavable bridge for subsequent two-dimensional electrophoretic analyses. Chemical attachment is carried out first, and the crosslink is completed by photolysis. Many of these so-called heterobifunctional molecules are listed in Table 5.1 and some of them, conforming to the criteria outlined below,... 

The functionalization reaction, which is particularly applied to collagen, is based on the aminomethylation of various substrates (see also Table 34, Chap. Ill) by employing the NH2 groups of the protein as Mannich amine reagents. Formaldehyde is preferred for crosslinking however, other agents, such as resols (see 432 in Chap. Ill,... 

Polyacrylamide gels are formed by the copolymerization of acrylamide monomers with a crosslinking agent to form a three-dimensional (3-D) network. The most commonly used crosslinker is N,N -methylene bis-acrylamide (Bis), but there are a variety of alternative reagents which can be used to impart special properties to the gels (see Table... 

Table 1 Crosslinking of LHC Il-less oxygen-evolving PS II complexes with bifunctional reagents with different chain lengths...

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