Purification and characterization of acyl-acyl carrier protein synthetase from oleaginous yeast and its role in triacylglycerol biosynthesis
| Autor: | Akanksha GANGAR, Anjali A. KARANDE, Ram RAJASEKHARAN |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2001 |
| Předmět: |
animal structures
Cytidine Triphosphate Fatty Acids Molecular Sequence Data Rhodotorula Uridine Triphosphate Cell Biology Biochemistry humanities Enzyme Activation Kinetics Adenosine Triphosphate stomatognathic system Carbon-Sulfur Ligases Multienzyme Complexes Acyl Carrier Protein bacteria lipids (amino acids peptides and proteins) Amino Acid Sequence Guanosine Triphosphate Molecular Biology Triglycerides Research Article |
| Zdroj: | IndraStra Global. |
| ISSN: | 2381-3652 |
| Popis: | Fatty acids are activated in an ATP-dependent manner before they are utilized. We describe here how the 10S triacylglycerol biosynthetic multienzyme complex from Rhodotorula glutinis is capable of activating non-esterified fatty acids for the synthesis of triacylglycerol. The photolabelling of the complex with [32P]azido-ATP showed labelling of a 35kDa polypeptide. The labelled polypeptide was identified as acyl-acyl carrier protein (ACP) synthetase, which catalyses the ATP-dependent ligation of fatty acid with ACP to form acyl-ACP. The enzyme was purified by successive PAGE separations to apparent homogeneity from the soluble fraction of oleaginous yeast and its apparent molecular mass was 35kDa under denaturing and reducing conditions. Acyl-ACP synthetase was specific for ATP. The Km values for palmitic, stearic, oleic and linoleic acids were found to be 42.9, 30.4, 25.1 and 22.7μM, respectively. The antibodies to acyl-ACP synthetase cross-reacted with Escherichia coli acyl-ACP synthetase. Anti-ACP antibodies showed no cross-reactivity with the purified acyl-ACP synthetase, indicating no bound ACP with the enzyme. Immunoprecipitations with antibodies to acyl-ACP synthetase revealed that this enzyme is a part of the 10S triacylglycerol biosynthetic complex. These results demonstrate that the soluble acyl-ACP synthetase plays a novel role in activating fatty acids for triacylglycerol biosynthesis in oleaginous yeast. |
| Databáze: | OpenAIRE |
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