Converting micrograms to moles for IgG

[Student]

This may sound a very silly question to many of you. Whilst I know how to
convert mass to moles for small molecules, I have never done it for large
proteins. For an IgG1 molecule, I know the size is approximately 150kDa.
Does this mean that 1 mole = 150,000grams? (It would be rather tedious to
add up all the molecular weights of the amino acids to get the molar mass!)

Thanks, and excuse my ignorance!