Biomedical subjects

R Tirindelli

Publications and source records attributed to R Tirindelli.

23 records · Page 2Linked to original sources

PubMed1988

The pyrazine-binding protein and olfaction.

1. The present results provide circumstantial evidence, but not a proof, that the Pyrazine-binding Protein is an odorant carrier molecule of fundamental importance. 2. At first sight a role for a secretory protein in olfaction is not obvious. 3. Odorants freely diffuse in air, in water and in lipids, and the use of carrier proteins, would seem superfluous unless a very special combination with the odorant occurs [Gaupp E. (1902) In Anatomie des Frosches, 2nd Edn, pp. 673. Vieweg-Verlag, Braunschweig]. 4. The possibility should be considered that the Pyrazine-binding Protein and the urinary proteins belong to a large family of species-specific secretory molecules which, with the odorant bound, directly stimulate the receptor cell.

Animals↗

PubMed1987

Immunocytochemical localization of pyrazine-binding protein in bovine nasal mucosa.

Polyclonal antibodies have been raised against purified bovine pyrazine-binding protein, a protein that binds the odorant 2-isobutyl-3-methoxypyrazine. These antibodies have been utilized in immunocytochemical experiments to localize the pyrazine-binding protein in bovine nasal mucosa. Tissue fragments, macroscopically identified as olfactory and respiratory mucosa, were fixed in Bouin's fluid and embedded in paraffin. Consecutive serial sections were processed for immunofluorescence studies and restained either with haematoxylin-eosin or with periodic acid Schiff-Alcian Blue. In both olfactory and respiratory mucosa, only seromucous tubulo-acinar glands were specifically labelled. These glands are located in the lamina propria underlying typical respiratory epithelium, even in those tissues that are macroscopically defined as olfactory mucosa.

Animals↗

PubMed1986

Effect of fluoride on the phosphodiesterase of bovine photoreceptors.

In the absence of the specific hormone, fluoride is able to activate the adenylate cyclase because it interacts with the GTP-binding protein. It has been reported that fluoride activates also the phosphodiesterase of the light-sensitive enzymatic cascade in dark-adapted retinal rod outer segments, but there is no indication that the GTP-binding protein is involved in this process or not. We show here that also in the photoreceptor system fluoride does interact with the GTP-binding protein in order to activate the phosphodiesterase in the dark. Further, we show evidences that fluoride solubilizes the GTP-binding protein in the dark and that the resulting complex activates the phosphodiesterase in dark-adapted rod outer segment membranes.

Animals↗

PubMed1985

Crystallization of an odorant-binding protein from cow nasal mucosa.

The first odorant-binding protein isolated from mammalian nasal mucosa is a dimer of subunits of identical molecular weight (19,000) that specifically binds bell pepper odorants, "green" smelling compounds. The protein can be purified in milligram quantities from tissue extractions by sequential use of a silica based anion exchange column and Mono-P chromatofocussing column. In the presence of the binding compound 2-isobutyl-3-methoxypyrazine and of the organic solvent 2-methyl-2,4-pentanediol (17%, v/v), the protein crystallizes in the monoclinic space group P2(1), with unit cell constants a = 54.3 A, b = 66.7 A, c = 41.5 A, beta = 97.2 degrees. From consideration of the crystal packing densities compatible with its unit cell, it can be concluded that two subunits of 19,000 Mr each are present in the asymmetric unit. The diffraction pattern on still photographs of this crystal form of the protein extends to 2.5 A resolution and allows for a detailed crystallographic investigation.

Animals↗

PubMed1985

Purification and characterisation of an odorant-binding protein from cow nasal tissue.

Cow nasal tissue contains a protein which shows specific binding activity for 'green' smelling compounds such as 2-isobutyl-3-methoxypyrazine. This protein has now been purified using anion-exchange fast protein liquid chromatography. The protein has a relative molecular mass of 40 0000-44 000, s = 3.1 +/- 0.3 S, pI = 4.7 +/- 0.1 with an absorbance maximum at 278 nm, and consists of two subunits with an identical relative molecular mass of 19 000. It is localised in the soluble fraction of cells from the olfactory mucosa and respiratory mucosa from the middle part of the maxillary and nasal turbinates, and is absent from all other tissues tested.

Animals↗