Autor: SANTOS,A.M.C - PIBIC (CNPQ)

Orientador: SANTORO,M.M.

Outros autores:

Linhas de pesquisa no CNPq: CIÊNCIAS BIOLÓGICAS / BIOFÍSICA MOLECULAR

Unidade: INSTITUTO DE CIÊNCIAS BIOLÓGICAS
Departamento: BIOQUÍMICA E IMUNOLOGIA

Palavras-Chave: MICROCALORIMETRIA - BETA TRIPISINA - TERMODINÂMICA

Trypsin is part of a large family of enzymes similar to chymotrypsin all containing a catalytic triad (Ser, Hist e Asp) and an oxianiônic hole in its active center.This protein has two domains, the first comprises the residues 1 to 105 and the second the remainig 106 to 229.Its secondary structure is characterized by the predominance of b-Sheet antiparalel,with little alpha helix .Commercial bovine Trypsin is a mixture of isoforms b , a and y-Trypsin and other proteins.These enzymes have low molecular weigt and are capable of hydrolyze peptides and ester bonds with specificity different for each isoform .A comparative study of activity of each isoform with different amide and ester substrates shows that the amidasic activity increase in the following order :isoform y, a and b, while with sterasic activity it is the inverse order. A calorimetric study of trypsinogen and b isoforms in acid pH shows that : a) at pH = 3.00, the enzyme denaturation displays a transitions between two states (native and denatured), b) in pH range of pH 3.00 - 4.20, the thermal denaturation of these enzymes are more complex, with a degree of aggregation of enzyme that is dependent on concentration of protein in solution. c)the thermodynamic parameters (DHVh , DHcal , DG, DS)were determined..

Apoio: CNPq