Non‐glycosylated recombinant pro‐concanavalin A is active without polypeptide cleavage.

The complex post‐translational processing of concanavalin A (Con A) in maturing jackbeans is unique because the non‐glycosylated mature active protein is circularly permuted in primary sequence relative to its own inactive precursor (glycosylated pro‐Con A) and to other legume lectins. We show here that non‐glycosylated pro‐Con A expressed in bacteria from recombinant cDNA (rec‐pro‐Con A) folds in vivo and in vitro to a stable form which is active without further processing. N‐glycosylation alone must therefore be sufficient to inactivate pro‐Con A‐‐a novel role for glycosylation in regulating activity during protein maturation.