Studies on the trehalase from the hemolymph of Triatoma infestans
Conter, P.F.; Vieira, M.M.; Veiga, L.A.
Revista Brasileira de Biologia 48(4): 761-769
1988
ISSN/ISBN: 0034-7108 PMID: 3071834 Document Number: 318727
The haemolymph of T. infestans contains trehalase and a peptide which is associated with a smaller molecule and is capable of inhibiting 90% of the trehalase activity present (and thus regulates glucose demand). This peptide, on isolation, was homogeneous by gel electrophoresis, had a molecular weight of about 20 000, had glutamic acid (22.6%), proline (12%) and alanine (10%) as principal amino acids, and contained 5.6% hexosamine. The influence of the inhibitor concentration on the trehalase activity was determined (Ki = 2.34x10-4) and the inhibition was shown to be of the competitive type. When heated for 2 min at 55 degrees C, the peptide lost 90% of its inhibitory capacity. The smaller molecule was not affected by heating.