Characterization and function of stentorin, the photoreceptor protein in Stentor coeruleus
Stentorin is a photoreceptor protein that is responsible for the step-up photophobic response and the negative phototaxis of an aneural unicellular ciliate protozoan, Stentor coeruleus. This protein was solubilized from the membrane of pigment granules and purified by the combination of gel filtration, hydroxylapatite chromatography, and DEAE-sepharose anionic exchange chromatography. SDS polyacrylamide gel electrophoresis revealed two red fluorescent bands for the purified stentorin reflecting the microheterogeneity of stentorin. The fluorescence lifetime study of stentorin employing the deuterium solvent isotope effect was conducted to confirm the proton dissociation from the chromophore at the excited state as a primary signal in the photosensory transduction in S. coeruleus. The increase of the amplitude of the anionic lifetime component in going from H/sub 2/O buffer to D/sub 2/O buffer is suggestive of the existence of the conjugate acid-base network of the photoreceptor protein for fast proton transfer. ATP-involvement in the photoresponse of S. coeruleus was investigated by using the firefly bioluminescence for ATP assay and the incorporation of /sup 32/Pi into ATP. Light-induced ATP level variation was detected only when cellular ATP was extracted by the boiling water method. The cellular ATP level was constant regardless of light illumination when extracted by trichloroacetic acid (TCA).
- Research Organization:
- Texas Tech Univ., Lubbock (USA)
- OSTI ID:
- 7191680
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Determining protein polarization proteome-wide using physical dissection of individual Stentor coeruleus cells
Ultrafast pump-probe spectroscopy of the photoreceptor stentorins from the ciliate stentor coeruleus
Related Subjects
PROTEINS
BIOLOGICAL FUNCTIONS
CHEMICAL COMPOSITION
FRACTIONATION
ATP
DEUTERIUM
ELECTROPHORESIS
FLUORESCENCE
ION EXCHANGE CHROMATOGRAPHY
ISOTOPE EFFECTS
PHOSPHORUS 32
PROTOZOA
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CHROMATOGRAPHY
DAYS LIVING RADIOISOTOPES
FUNCTIONS
HYDROGEN ISOTOPES
INVERTEBRATES
ISOTOPES
LIGHT NUCLEI
LUMINESCENCE
MICROORGANISMS
NUCLEI
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PHOSPHORUS ISOTOPES
RADIOISOTOPES
SEPARATION PROCESSES
STABLE ISOTOPES
550201* - Biochemistry- Tracer Techniques