Yeast Fms1 is a FAD-utilizing polyamine oxidase

Area of Science:

• Biochemistry
• Molecular Biology
• Enzymology

Background:

• Polyamines are crucial for cellular processes.
• The role of Saccharomyces cerevisiae Fms1 protein in polyamine metabolism was previously suggested.
• Understanding Fms1's enzymatic activity is key to elucidating its biological function.

Purpose of the Study:

• To biochemically characterize the recombinant Saccharomyces cerevisiae Fms1 protein.
• To determine the substrates and products of Fms1-mediated oxidation.
• To investigate the kinetic properties of Fms1 activity.

Main Methods:

• Recombinant expression and purification of Fms1 protein.
• Enzyme kinetics assays using various polyamine substrates.
• Product identification using biochemical methods.

Main Results:

• Fms1 is identified as a flavin adenine dinucleotide (FAD)-binding polyamine oxidase with a 1:1 FAD:Fms1 stoichiometry.
• Fms1 efficiently oxidizes spermine, N(1)-acetylspermine, and N(1)-acetylspermidine, producing spermidine and 3-aminopropanal from spermine.
• N(8)-acetylspermidine is a poor substrate, and spermidine is not oxidized by Fms1.

Conclusions:

• Fms1 functions as a polyamine oxidase in Saccharomyces cerevisiae.
• The enzymatic activity of Fms1 supports its proposed role in generating beta-alanine from spermine for pantothenic acid synthesis.
• Fms1's substrate specificity provides insights into polyamine catabolism pathways.