The Propeptide is Required for In Vivo Formation of Active Protealysin.

Two structurally distinct N-terminal propeptides are known in thermolysin-like proteases (TLPs). Propeptides of the first type are similar to the prosequence of thermolysin, while the second type propeptides resemble the protealysin propeptide. At the same time, the catalytic domains of all enzymes of the family are highly similar.

Crystal structure of the protealysin precursor: insights into propeptide function.

Protealysin (PLN) belongs to the M4 family of peptidases that are commonly known as thermolysin-like proteases (TLPs). All TLPs are synthesized as precursors containing N-terminal propeptides. According to the primary structure of the N-terminal propeptides, the family is divided into two distinct groups.

Processing of protealysin precursor.

Protealysin, a protease previously described by us in Serratia proteamaculans, belongs to the group of thermolysin-like proteases (TLPs) that differ from classical TLPs by the precursor structural organization. The propeptide of protealysin precursor has no significant structural similarity to the propeptides of most TLPs. The functions of protealysin-like precursors and mechanisms of their action remain unclear.