Letter from Heinrich Muldner to Marshall W. Nirenberg
This letter is an example of the collaborative nature of Nirenberg's work and his accessibility to other scientists.
Muldner, working at the Max Planck Institute for Physiological Chemistry, includes details from recent experiments with corresponding
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1969-11-03 (November 3, 1969)
Max-Planck-Institut fur Physikalische Chemie
Nirenberg, Marshall W.
Reproduced with permission of the Max-Planck-Institut fur Biophysikalische Chemie.
Beyond the Laboratory: Professional, Personal, and Political Life, 1967-2002
With separate mail I will send you next week new preparations of the commercially available Vibrio cholera-sialidase and different
At the moment we have two pure sialidases; the one I have already mentioned which hydrolizes both 2 - 6' and 2 - 3'
linkages of sialic acid to carbohydrates. And another one from influenza A2 virus which readily splits only 2 - 3' linkages.
This is the characteristic feature of myxovirus sialidases.
In all (7) isolated acidic oligosaccharides we find 4 types of bonds through which the sialic acid residues are linked to
Type I 2 - 3 linkage to galactose
II 2 - 6 linkage to galactose
III 2 - 6 linkage to hexosamine
IV 2 - 8 linkage from sialic acid to sialic acid
Type I in gangliosides, fetuin (JbC 239 567 1964) and acidic 2-glycoproteins from humans
(BBA 49 250 1961).
Type III in submaxillaris mucin
(BBA 38 513 1960)
Type IV in ganglioside III and IV and colominic acid (polymeric sialic acid) (Biochem. 3 247 1964).
As you can see the sialidase we will send splits all these bonds. Only type IV makes some difficulties because in addition
to the 2 - 8 linkage a 1 - 9 labile ester linkage can easily be formed and prevent the enzyme to split the 2 - 8 linkage.
In these cases one has to open the labile ester linkage first with n/100 NaOH (few minutes). There are of course other difficulties
we are just looking for and I shall tell you later. I came back for some weeks to prepare larger amounts of our ATPase which
is active on bilayer. I think I will return in spring and hope to see you then and give a talk.
Thank you very much again for this valuable introduction to the nerve growth factor.