1.Beta-sheet and associated turn signatures in vibrational Raman optical activity spectra of proteins.
Wen ZQ;Hecht L;Barron LD Protein Sci. 1994 Mar;3(3):435-9.
We have measured the aqueous solution vibrational Raman optical activity (ROA) spectra of concanavalin A, alpha-chymotrypsin, and beta-lactoglobulin, all of which are rich in beta-sheet, together with that of the model beta-turn peptide L-pro-L-leu-gly-NH2. Possible ROA signatures of antiparallel beta-sheet include a strong sharp positive band at approximately 1,313 cm-1 associated with backbone amide III C alpha H and NH deformations, and an amide I couplet, negative at low wavenumber and positive at high, centered at approximately 1,658 cm-1. Negative ROA bands in the range approximately 1,340-1,380 cm-1, which might originate in glycine CH2 deformations, appear to be characteristic of beta-turns. Our results provide further evidence that ROA is a more incisive probe of protein conformation than conventional vibrational spectroscopy, infrared, or Raman, because only those few vibrational coordinates within a given normal mode that sample the skeletal chirality directly contribute to the corresponding ROA band intensity.
2.[Effect of some fragments of peptide hormones on the content of biogenic monoamines from mouse brain].
Zile RK;Odynets TG;Klusha VE Biokhimiia. 1979 Jan;44(1):93-96.
The effect of some tripeptides, which are fragments of peptide hormones, and their analogs on the content of biogenic monoamines (BM) from albino mice brain was studied. It was found that thyroliberin, melanostatin and the C-terminal tripeptide of gonadoliberin activate the dophaminergic (DA-ergic) system in the forebrain of mice treated with reserpine or haloperidol, whereas the C-terminal tripeptide of gastrin acts as a synergic blocker of the DA receptors. The N-terminal tripeptides (with and without the amido group) do not affect the content of BM. No effect of the tripeptides was observed in intact animals. It is assumed that the agonistic or antagonistic effect of the tripeptides on BM is due to certain structural peculiarities of the tripeptides, e.g. the presence of the C-terminal amido group and their endogenous nature.
3.[Functional state of the sympathetic-adrenal system in melanocyte-stimulating hormone deficiency under the effect of the melanocyte-inhibiting factor of the hypothalamus].
Mel'nik BE;Robu AI;Paladiĭ ES Probl Endokrinol (Mosk). 1980 Mar-Apr;26(2):57-60.
Fluorometry was applied to the study of the content of a number of amines (DOPA), adrenalin, noradrenaline) in the adrenal glands and various structures of the rat brain in endogenous deficiency of melanocyte-stimulating hormone of the hypophysis caused by parenteral administration of synthetic melanostatin (MIF) of the hypothalamus. The amines content in the adrenal glands medulla, and also in the medulla oblongata; the cerebellum, and the large hemispheres proved to change 30 to 60 min after MIF administration. The results obtained indicated that various links of the sympathico-adrenal system could take part in the mechanism of MIF action on the hypophysis.
