[Phenylalanyl-tRNA-synthase from human placenta: isolation and characteristics]

Area of Science:

• Biochemistry
• Molecular Biology
• Enzymology

Context:

• Phenylalanyl-tRNA synthetase (EC 6.1.1.20) is crucial for protein biosynthesis, catalyzing the specific attachment of phenylalanine to its cognate tRNA.
• Understanding the properties of human enzymes is vital for comprehending cellular processes and potential therapeutic targets.

Purpose:

• To isolate and purify phenylalanyl-tRNA synthetase from human placenta.
• To characterize the molecular mass, subunit composition, and kinetic parameters (Km values) of the purified enzyme.

Summary:

• Human placental phenylalanyl-tRNA synthetase was purified 14,800-fold with an 8% yield.
• The native enzyme has a molecular mass of 270 kDa, with subunits of 74 kDa (alpha) and 63 kDa (beta).
• Kinetic analysis revealed Km values of 6.6 x 10(-8) M for tRNA, 8.3 x 10(-5) M for ATP, and 5.8 x 10(-6) M for phenylalanine.

Impact:

• Provides essential biochemical data on human phenylalanyl-tRNA synthetase, aiding in the study of protein synthesis regulation.
• Characterization of enzyme kinetics and subunit structure offers insights into enzyme function and potential interactions.
• This purified enzyme serves as a valuable resource for further structural and functional investigations in molecular biology and related fields.