{'fraction_non_alphanumeric': 0.02584493041749503, 'fraction_numerical': 0.041749502982107355, 'mean_word_length': 6.22488038277512, 'pattern_counts': {'":': 0, '<': 1, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Characterization of the in vitro activity of the Arabidopsis thaliana lysoglycerophospholipid acyltransferase, At1g78690

The Arabidopsis thaliana enzyme At1g78690 is an acyltransferase that acylates 1‐acyllysophosphatidylglycerol or 1‐acyllysophosphatidylethanolamine (lyso‐PE) to phosphatidylglycerol or phosphatidylethanolamine (PE), respectively, in vitro. However, the over expression of the protein in Escherichia coli leads to the accumulation of the headgroup‐acylated lipid acylphosphatidylglycerol (APG) in vivo. In order to understand how the acylation of lyso lipids impacts the metabolism of APG, we are investigating in depth the in vitro reaction of At1g78690. A N‐terminal, 6‐histidine tagged At1g78690 was overexpressed in E. coli and then cell lysates fractionated to yield cytosol and membranes. The At1g78690 activity, assessed by monitoring the transfer of 14C‐labeled palmitate from palmitoyl‐CoA to lyso‐PE, fractionates nearly equally between the cytosol and membrane fractions indicating that At1g78690 is a peripheral membrane protein. Varying the in vitro reaction conditions has shown that EDTA and EGTA stimulate activity. Furthermore, MgCl2 at concentrations <10 mM inhibit At1g78690 activity. Preliminary trials with inclusion of NaCl showed improved activity. Assessments of the pH optimum and detergent dependence, as well as purification of At1g78690 are underway. This work was supported by a National Science Foundation‐Research at Undergraduate Institution Award #1152463.