Conjugation to protein

Small tfbiquitin-like modifier represents a family of evolutionary conserved proteins that are distantly related in amino-acid sequence to ubiquitin, but share the same structural folding with ubiquitin proteins. SUMO proteins are covalently conjugated to protein substrates by an isopeptide bond through their carboxyl termini. SUMO addition to lysine residues of target proteins, termed SUMOylation, mediates post-transla-tional modification and requires a set of enzymes that are distinct from those that act on ubiquitin. SUMOylation regulates the activity of a variety of tar get proteins including transcription factors. 

Figure 10 Structure of the target analyte phenoxybenzoic acid (PBA). The arrows point to the ideal sites for conjugation of the molecule to proteins for optimum recognition. Use of site 2 for conjugation to protein resulted in antibodies that recognized free PBA poorly...

A further type of vaccine included in the subunit category is the capsular polysaccharide vaccines, for example, those against Haemophilus influenzae and meningococcal meningitis. In this case an extract of the polysaccharide outer capsule of the bacterium is used as a vaccine and is sometimes conjugated to protein to... 

Soon after it was shown that ubiquitin is conjugated to proteins, it was determined that this was a reversible process and deubiquitinating enzymes, or DUBs, could remove ubiquitin from ubiquitinated proteins [18, 19]. As the genes for ubiquitin and ubiquitin-like proteins were identified it became clear that all ubiquitin family members were synthesized as proproteins and processed to reveal the C-terminal glycylglycine of the active proteins [20]. Based on this information, DUBs were defined as proteases that cleave at the C-terminus of ubiquitin or ubiquitin-like proteins to reverse conjugation to target proteins and also process the proproteins. 

Q82 Prevenar is a pneumococcal vaccine that contains polysaccharide from seven capsular types of the pneumococcus that is conjugated to protein. Prevenar should only be administered to children who are at an increased risk of pneumococcal infection. 

To facilitate accesses to suitably functionalized sialic acid derivatives and complex sialyloligosaccharides for other usehil neoglycoconjugates, phase transfer catalysis (PTC) has been exploited extensively [for reviews see 42]. This process provided a wide range of carbohydrate derivatives under essentially clean Sn2 transformations. In the case of acetochloroneuraminic acid 1, the PTC reactions always provided inverted a-sialic acid derivatives [43]. para-Formylphenyl sialoside 7 [44], together with many other sialoside derivatives such as 8-10 [43], including thioacetate 12 [45] and azide 14 [46], were thus obtained (Scheme 1). Aldehyde 7 and similar glycosides are of particular interest since they could be directly conjugated to protein by reductive amina-tion after suitable deprotection [44]. 

By their very nature, subcellular and subunit vaccines are nonreplicative and often share drawbacks similar to inactivated vaccines in their need for repeated dosing and help with adjuvants (or conjugation to proteins) to enhance their... 

A significant degree of sensitivity of the functional properties of the conjugates to protein/polysaccharide ratio and polysaccharide molecular weight might be expected for various reasons. 

Key to the successful production of generic antisera for the tetracycline antibiotics has been the synthesis of the hapten 4-hydrazino-4-dedimethylamino-tetracycline and its subsequent conjugation to protein (73). The immunochemical method developed from this sera could detect tetracycline, chlortetracycline, and oxytetracycline residues in meat and milk, with adequate sensitivity (19). 

Isomer Number of conjugated double bonds Absorption maximum (nm) when conjugated to proteins... 

Haemophilus influenzae type b conjugate (Hib) Bacterial polysaccharid e conjugated to protein Intramuscular One dose (see Table 1-2 for childhood schedule) Not recommende d 1. For all childr en 2. Asple nia and... 

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