Preparation and Properties of the Recombinant Tenebrio molitor SerPH122—Proteolytically Active Homolog of Serine Peptidase

Pseudoenzymes are homologs of active enzymes that have amino acid substitutions in the active center and, therefore, usually do not possess enzymatic activity. In this work, a recombinant proprotein (proSerPH122) of the homolog of serine peptidases of the S1 family from the yellow mealworm (Tenebrio molitor) was obtained in the yeast producer strain Komagataella kurtzmanii. The target His6-tagged protein was produced in a glycosylated form during secretion in yeast. The properties of both glycosylated and deglycosylated forms were studied. The proSerPH122 homolog with the replacement of active site Ser with Thr was pretreated with trypsin to study the enzymatic properties. The processed, mature homolog SerPH122 was shown to have low, but reliably detectable activity on the chromogenic substrate Suc-Ala-Ala-Pro-Phe-pNA, and this activity did not depend on the glycosylation level.