PubMed Central. The tra -1 and tra -2 sex-determining genes promote female fates in Caenorhabditis elegans. Classical genetic studies placed tra -1 as the terminal regulator of the pathway with tra -2 acting upstream as a regulator of regulators of tra Here we report the surprising result that the TRA -1 transcription factor binds the intracellular domain of the TRA -2 membrane protein.
This binding is dependent on the MX regulatory domain, a region of the TRA -2 intracellular domain shown previously to be critical for the onset of hermaphrodite spermatogenesis. The functional importance of the TRA -1β TRA -2 physical interaction is supported by genetic interactions between tra -1 0 and tra -2 mx mutations: a reduction of tra -1 gene dose from two copies to one copy enhances the tra -2 mx feminization phenotype, but has no apparent somatic effect.
Surface-enhanced Raman spectrum of Gly-Gly adsorbed on the silver colloidal surface. Raman and SERS spectra of homodipeptide Gly-Gly and Gly were recorded and compared in this paper, and band assignment for the functional groups contained in these molecules was analyzed in detail. The time-dependent SERS spectra of Gly-Gly are characterized by the increase in intensity of bands primarily representing the vibrational signatures emanating from the amino and amide moiety of Gly-Gly molecule.
It is found that the adsorption style of Gly-Gly on the silver colloid changes as time goes on; at 5 min after adding the sample to the silver colloid, Gly-Gly adsorbs on silver surface firstly through the carboxylate, amino and amide groups, and then the carboxylate group is far away from the silver surface at 10 min to 3 days.
The SERS variation of Gly-Gly with the change of pH suggests that the adsorption style is pH-dependent, the different adsorption behavior of the Gly-Gly occurs on silver surface at different pH values.
