Aspects of chemoattractant recognition by the alga Dunaliella tertiolecta
Studies on the molecular nature of algal chemotaxis were performed using the halophilic chlorophyte Dunaliella tertiolecta as a model. Several physical and chemical parameters for generation of maximum chemotactic response in capillary assays are described. Inhibition of chemotaxis to NH/sub 4//sup +/ and several aromatic amino acid by sublethal concentrations of certain heavy metals, including Zn/sup 2 +/, Co/sup 2 +/, Ni/sup 2 +/, Cu/sup 2 +/, and Hg/sup 2 +/ is demonstrated. Inhibition by Zn/sup 2/ of the response of NH/sub 4//sup +/ is partially reversed by increased concentrations of Ca/sup 2 +/. Attraction of L-phenylalanine, L-tyrosine, L-tryptophan, their structural analogs, and other compounds has been quantified using a capillary assay. Radiolabeled L-phenylalanine was used as a ligand to investigate algal binding and uptake. No internalization of the amino acid by D. tertiolectra occurred, even after 3 hr. Specific binding of /sup 3/H-L-phenylalanine was below 100 molecules per alga at 10/sup -8/ M L-phenylalanine. No evidence for the alteration of L-phenylalnine by D. tertiolecta was found following 22 hr incubation with the substrate in light or darkness. To further probe the molecular components of the chemosensory system of D. tertiolecta, a procedure for isolation and purification of trinitrobenzene sulfonic acid (TNBS)-labeled plasma membrane vesicles was developed. Plasma membrane purity was assessed by criteria of chlorophyll content, succinic dehydrogenase activity and protein pattern.
- Research Organization:
- Maryland Univ., College Park (USA)
- OSTI ID:
- 6984830
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Photoregulation of the light-harvesting chlorophyll protein complex associated with photosystem II in Dunaliella tertiolecta
Free ammonia inhibition of algal photosynthesis in intensive cultures
Related Subjects
59 BASIC BIOLOGICAL SCIENCES
CHEMORECEPTORS
MOLECULAR STRUCTURE
METALS
BIOLOGICAL EFFECTS
PHENYLALANINE
UPTAKE
TRITIUM COMPOUNDS
ALGAE
AMINO ACIDS
CALCIUM COMPOUNDS
COBALT COMPOUNDS
COPPER COMPOUNDS
INHIBITION
LIGANDS
MERCURY COMPOUNDS
NICKEL COMPOUNDS
ZINC COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
CARBOXYLIC ACIDS
ELEMENTS
LABELLED COMPOUNDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
PLANTS
TRANSITION ELEMENT COMPOUNDS
560300* - Chemicals Metabolism & Toxicology
550201 - Biochemistry- Tracer Techniques