Assertion: hemoglobin's subunit | /r/HasProperty | linked to each other
Facets:
value: by noncovalent interactions
type: MANNER
Source sentences:
text: The molecular weight of the tetramer is 64,500; the molecular weight of the α- and β-chains is approximately 16,100 each, and the four subunits are linked to each other by noncovalent interactions.