Preparation protein toxins used

Vaccination has proved to be one of the most useful scientific developments in the control and eradication of human disease. Early vaccines were based on whole-organism preparations, or on protein toxins isolated from different bacteria and, although these methods... 

The toxins used for the chemical construction of ITs are bRT, RTA in deglycosylated form (dgRTA), two ribosome-inactivatiing proteins (RIPs) (PAP and saporin), and PE. The preparation of some of these toxins is described in Subheading 3.3.1. It should be noted that presently almost all plant and bacterial toxins used for the preparation of ITs can also be expressed in recombinant form in E. coli. 

Excitable tissue preparations were obtained fresh daily from live animals using the technique described by Dodd et al. (12). Protein was measured on each synapto-some preparation using the Coomassie Brilliant Blue dye technique described by Bradford (13) results were expressed as "toxin bound per mg synaptosome protein". 

SATA has been used to form conjugates with avidin or steptavidin with excellent retention of activity (Chapter 23, Section 3.1). It also has been used in the formation of a therapeutically useful toxin conjugate with recombinant CD4 (Ghetie et al., 1990), to study syntaxin proteins (Amessou et al., 2007), to prepare bispecific antibodies (Lindorfer et al., 2001), and to make a unique polylysine conjugate as a vehicle for drug delivery (Sakharov et al., 2001). 

Blattler, W.A., Kuenzi, B.S., Lambert, J.M., and Senter, P.D. (1985b) New heterobifunctional protein cross-linking reagents and their use in the preparation of antibody-toxin conjugates. Photochem. Photobiol. 42, 231. 

Losytska V, Naida I, Tsiganov V (1997) Toxin-binding abihty of blood serum proteins in burned patients with the use of Enterosgel. In Biosorption methods and preparations in prophylactic and therapeutic practice, Eirst Conference, Kyiv (In Ukrainian), pp 121-122... 

The chemical synthesis of the Amanita toxins has presented several problems, in particular those related to the formation of the sulfur bridge. The latter has been explored with model compounds.[2 31 It has been found that the synthesis of the (sulfanyl)indole moiety can be achieved by reacting an indole compound with an alkanesulfenyl chloride. A model tryptathionine compound has been prepared by reacting A-acyl-L-cysteine and /V-acyl-L-tryptophan in the presence of A-chlorosuccinimide in glacial acetic acid at room temperature.[4] The sulfanylation reaction has been subsequently exploited for the selective chemical modification of tryptophan residues in proteins using 2-nitrophenylsulfenyl chlorideJ5 ... 

For instance, if toxin A chain—antibody conjugates are to be prepared, the antibody can be similarly activated with SPDP, but in this case not treated with reductant. After removal of excess cross-linker, the activated antibody can be directly mixed with isolated A chain to create the conjugate (Fig. 320). This procedure makes use of the indigenous sulfhydryl residues produced during reductive separation of the A and B chains and therefore does not require cross-linker thiolation of one of the proteins. 

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