Penaeus vannamei isotrypsins: purification and characterization.
Three isotrypsins from digestive gland of Penaeus vannamei were purified and characterized by molecular, biochemical and kinetic parameters. Purified isotrypsins A, B, and C are glycoproteins with molecular masses between 30.2 and 32.9 kDa, and, therefore similar to other trypsins. The isoelectric points are anionic and different among the three isotrypsins: pH 3.5 for isotrypsin A, pH 3.0 for isotrypsin B, and pH 4.5 for isotrypsin C. Differences in the NH(2)-terminal amino acid sequences allowed us to define three different protein entities that match isotrypsins previously deduced by cDNA. Isoform C has higher physiological efficiency and specific activity, lower K(m), and requires higher concentrations of Ca(+2) to reach the same activity as the other two isotrypsins.
Sainz
Juan Carlos
JC
Laboratorio de Bioquímica, Centro de Investigaciones Biológicas del Noroeste. Mar Bermejo No. 195, Col. Playa Palo de Santa Rita, La Paz B.C.S. 23090, Mexico.
García-Carreño
Fernando L
FL
Hernández-Cortés
Patricia
P
D000818:Animals; D004795:Enzyme Stability; D005088:Exocrine Glands / Q000201:enzymology; D006031:Glycosylation; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D007527:Isoenzymes; D007700:Kinetics; D033561:Penaeidae / Q000201:enzymology*; D013696:Temperature; D014357:Trypsin / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*
D007527:Isoenzymes; D014357:Trypsin