The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)

Evidence for isoaspartyl (deamidated) forms of mouse epidermal growth factor.

A variant form of mouse submaxillary gland epidermal growth factor ( EGF) was identified by isocratic reversed-phase HPLC of EGF obtained by Bio-Gel P-10 column chromatography ("culture grade"). The variant form was essentially absent in preparations of EGF further purified by chromatography on DEAE-cellulose ("receptor-grade" EGF). The spectral properties and amino acid composition of the variant form (EGF-I) could not be distinguished from those of the intact polypeptide isolated by HPLC (alpha- EGF). Receptor-binding and mitogenic properties of EGF-I were also equivalent to those of alpha- EGF. These data suggested that EGF-I was structurally very similar to EGF. However, the very low yield (less than 4%) obtained by Edman degradation indicated that the N-terminal (Asn1) of the polypeptide was modified. Isoelectric focusing of EGF-I revealed two major immunoreactive bands: one with a pI equivalent to that of alpha- EGF (pI 4.6) and another at pI 4. 1. Alkaline treatment of alpha- EGF (0.1 M NH4OH) yielded peak material by HPLC that coeluted with EGF-I; the alkaline-generated EGF-I yielded bands that also focused at pH 4.6 and 4. 1. Ammonium hydroxide treatment of [des-Asn1]-EGF (beta- EGF) did not produce conversion to EGF-I. On the basis of these data, we propose that EGF-I was formed by selective deamidation of the N-terminal Asn of intact EGF. This notion is also supported by liquid secondary ion mass spectrometry, which showed that EGF-I was approximately 1.5 mass units greater than alpha- EGF. The heterogeneity observed by isoelectric focusing supports previous studies which have shown that, following deamidation of N-terminal asparagine, a beta-aspartyl shift can occur, which in the present study might yield succinimido-aspartyl1- EGF and beta-aspartyl1- EGF. Low yields observed during Edman degradation indicate that negligible amounts occur as the alpha-aspartyl1- EGF isomer.[1]


  1. Evidence for isoaspartyl (deamidated) forms of mouse epidermal growth factor. DiAugustine, R.P., Gibson, B.W., Aberth, W., Kelly, M., Ferrua, C.M., Tomooka, Y., Brown, C.F., Walker, M. Anal. Biochem. (1987) [Pubmed]
WikiGenes - Universities