| | 1 | Author
| G. Uhlenbruck, B. P. Chatterjee, U. Schuldes | Requires cookie* | | | Title
| Schiff Base Form ation: Dem onstrated by a Precipitin Reaction in A g a r  | | | | Abstract
| High-m olecular weight polyaldehydes, which can be o b tained by periodate oxidation of glycosubstances, especially polysaccharides, do precipitate in a specific way by Schiff base formation, when diffusing in agar gel against high-m olecular weight, naturally occurring polyamines. album (m istletoe), R icinus com m unis and from the bivalve clam Tridacna m axim a (see Fig. l a) . Also the plant lectins from Ononis spinosa and Abrus precatorius do give such a precipitin reaction. This precipitation phenomenon however is abolished, when the terminal D-galactose (/?-l-6 linked) has been oxidized by sodium periodate (F ig . l b) , whereas the precipitin reaction due to Schiff base form ation does not occur with the genuine, un treated arabinogalactan (F ig . 1 a) . N egative reac tions are also seen after borohydride reduction or by blocking the carbonyl groups (o r the amino groups) by other methods [ 1 1 ] *. Oxidation o f lymphocytes from a variety of spe cies with either sodium periodate, galactose-oxidase or neuraminidase and galactose-oxidase induces blastogenic transformation [ 1 — 5 ], or lymphocyte cytotoxicity [ 6]. In addition, tumor cell killing occurs, when by the same procedures artificial con tacts are established between normal macrophages and tumor cells [ 7 ]. Although these intriguing phenomena are not yet completely elucidated, it is assumed that cross-linkages via Schiff bases play an important role [6 — 8]. The only evidence for this hypothesis is given by the fact, that sodium b oro hydride treatment abolishes the effect. It was there fore desirable, to have an in v itro model for the form ation o f Schiff bases in order to study the inter action o f different membrane glycosubstances and proteins. A s standard materials for developing a representative precipitin experiment we have first chosen periodate-treated arabinogalactan from plant origin [9 ] and polylysine as amino group donator [10]. In Fig. 1 it is demonstrated, that Schiff base fo r mation between these two components indeed can be made visible in form o f a precipitation line. In addition, b iological substances with free amino groups, like histone [ 10], lysozyme [ 10] and haem oglobin [1 1 ] react in a similar way (F ig . 1 b), while a synthetic basic polym er without any amino groups, namely polybrene [ 10], does not pre cipitate as has been found by us. On the other hand, genuine arabinogalactan precipitates with some anti-galactosyl specific lectins like the one from Viscum | | | |
Reference
| Z. Naturforsch. 33c, 442 (1978); received February 2 1978 | | | |
Published
| 1978 | | | |
Keywords
| Basic Polyam inoacids Periodate-Treatment, Arabino-galactan, Lectins, Cell Aggregation | | | |
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| default:Reihe_C/33/ZNC-1978-33c-0442_n.pdf | | | | Identifier
| ZNC-1978-33c-0442_n | | | | Volume
| 33 | |
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