Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2001 Oct;13(10):2191–2210. doi: 10.1105/tpc.010192

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

Copyright © 2001, American Society of Plant Biologists

PMC Copyright notice

Figure 5. — PLA1 Activity of the DAD1 Protein.

(A) pH dependence of DAD1 activity. The MBP-DAD1dE protein was incubated with PC in phosphate buffers of various pH levels for 30 min at 25°C, and the released fatty acids were quantified. Data are expressed as the relative activities compared with the activity at pH 6.0, which was assigned a value of 1.0.

(B) Substrate specificity of DAD1 activity. The MBP-DAD1dE protein and R. miehei lipase were incubated with PC, MGDG, or trilinolein (TG), and the released free fatty acids were quantified. Data are expressed as the relative activities compared with the maximum activity for each enzyme (i.e., the activity for PC was assigned a value of 1.0 for MBP-DAD1dE, and the activity for MGDG was assigned a value of 1.0 for R. miehei lipase). Closed bars, MBP-DAD1dE; open bars, R. miehei lipase.

(C) and (D) Substrate specificity of DAD1 activity with respect to sn positions.

(C) The MBP-DAD1dE protein was incubated with 1-palmitoyl-2-linoleoyl-PC. After incubation for the indicated times, the amounts of palmitic acid and linoleic acid in the free fatty acid fraction and in the lysoPC fraction were measured by gas chromatography. Open circles, palmitic acid in the free fatty acid fraction; closed squares, linoleic acid in the lysoPC fraction; open squares, linoleic acid in the free fatty acid fraction; closed circles, palmitic acid in the lysoPC fraction.

(D) The MBP-DAD1dE protein was incubated with 1-palmitoyl-2-¹⁴C-linoleoyl-PC. As controls, MBP or buffer (no protein) was added in place of MBP-DAD1dE. After separation by thin layer chromatography, the radioactivity in the bands for ¹⁴C-PC (open bars), ¹⁴C-free fatty acid (hatched bars), and ¹⁴C-lysoPC (closed bars) was quantified and expressed as a proportion of the sum of the three fractions.