Mammals possess two genetically distinct but closely re r be if lated forms of lactate dehydrogenase (LDH), the M type (which predominates in skeletal muscle) and the H type (which predominates in heart tissue). Before the X-ray structure of LDH was owing known, the oligomeric state of LDH was determined by dissociat r box, quad ing M type and H type LDH to their component subunits and then reconstituting the mixture. This treatment yielded five elecaphics trophoretically distinct isozymes (catalytically and structurally th the similar but genetically distinct enzymes from the same organism), L AIY. M₄, M₃ H, M₂ H₂, MH₃, and H₄, thereby demonstrating that LDH is most a tetramer. What are the relative amounts of each isozyme formed , Car- when equimolar amounts of M₄ and H₄ are so hybridized?
