Phytochrome from green plants:

Technical Report · Tue Mar 01 04:00:00 EST 1988

OSTI ID:5266439

Quail, P H

This research has been directed toward characterizing and purifying the molecular species of phytochrome detected in green Avena tissue. We have found major differences between the phytochrome extracted from green and from etiolated tissue as regards immunochemial and spectral properties. In addition, we have established: (a) that the predominant ()approximately)80% of total) phytochrome polypeptide in green tissue has a relative molecular mass (Mr) of 118,000;(b) that the proteolytic peptide map of this 118,000-Mr species differs considerably from that of 124,000-Mr phytochrome from etiolated tissue;(c) that the green-tissue, 118,000-Mr polypeptide carries only one of three spatially separate epitopes that are present on etiolated-tissue phytochrome (i.e., an epitope in the carboxy-terminal domain recognized by Type 3 monoclonal antibodies);(d) that the minor phytochrome species in green tissue ()approximately)20% of total) resembles that in etiolated tissue in that it is 124,000-Mr and is immunoprecipitable with polyclonal, anti-etiolated-oat-phytochrome antibodies, thereby accounting for the previously observed limited population of immunoprecipitable activity in green extracts;and (e) that the 118,000-Mr green-tissue molecule migrates on non-denaturing size exclusionchromatography as a )approximately)320 kDa entity, suggesting a quaternary structure similar to etiolated tissue 124,000-Mr phytochrome. A new purification protocol that enriches the green-tissue phytochrome )approximately)200-fold has been developed. The preparations obtained in this way are apparently free of residual endogenous proteolytic activity. We have examined the regulation of the level of the 118,000-MR species during seedling developement and have obtained evidence that the abundance of this species is not modulated by light, in contrast to its etiolated-tissue counterpart. 12 refs., 7 figs., 1 tab.

• Research Organization: Wisconsin Univ., Madison (USA)
• DOE Contract Number: AC02-81ER10903
• OSTI ID: 5266439
• Report Number(s): DOE/ER/10903-8; ON: DE88007511
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
CEREALS
CHROMATOGRAPHY
FRACTIONATION
GRASS
IMMUNOASSAY
LIQUID COLUMN CHROMATOGRAPHY
OATS
ORGANIC COMPOUNDS
PHYTOCHROMES
PIGMENTS
PLANTS
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