Angiotensin converting enzyme of Thalassophryne nattereri venom.
Animal venoms are complex mixtures, including peptides, proteins (i.e., enzymes), and other compounds produced by animals in predation, digestion, and defense. These molecules have been investigated regarding their molecular mechanisms associated with physiological action and possible pharmacological applications. Recently, we have described the presence of a type of angiotensin converting enzyme (ACE) activity in the venom of Thalassophryne nattereri. It is a zinc-dependent peptidase with a wide range of effects. By removing dipeptide His-Leu from terminal C, the ACE converts angiotensinI (AngI) into angiotensin II (AngII) and inactivates bradykinin, there by regulating blood pressure and electrolyte homeostasis. The fractionation of T. nattereri venom in CM-Sepharose indicated a peak (CM2) with angiotensin-converting activity, converting AngI into Ang II. Electrophoresis on polyacrylamide gel (12%) revealed one band with 30kDa for CM2 similar in size to natterins, which are toxins with proteolytic activity found in T. nattereri venom. Mass spectrometry indicated that the protein sequence of the ACE purified from T. nattereri venom corresponds to natterin 1. The isolated protein has also demonstrated inhibition through captopril and EDTA and is characterized as a classic ACE. Thus, the isolated enzyme purified from T. nattereri venom is the first ACE isolated from fish venom.
Instituto de Química e Biotecnologia, Universidade Federal de Alagoas, Maceió, Brazil.
Maria Elizabeth
ME
da Costa Marques
Instituto de Química e Biotecnologia, Universidade Federal de Alagoas, Maceió, Brazil.
Humberto
H
de Araújo Tenório
Instituto de Química e Biotecnologia, Universidade Federal de Alagoas, Maceió, Brazil.
Claudio Wilian Victor
CW
Dos Santos
Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
Daniel Moreira
DM
Dos Santos
Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
Maria Elena
ME
de Lima
Instituto de Química e Biotecnologia, Universidade Federal de Alagoas, Maceió, Brazil. Electronic address: hugobqi@yahoo.com.br.
Hugo Juarez Vieira
HJ
Pereira
D000595:Amino Acid Sequence; D000818:Animals; D024541:Batrachoidiformes / Q000378:metabolism*; D002412:Cations; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D005397:Fish Venoms / Q000201:enzymology*; D007703:Peptidyl-Dipeptidase A / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D016415:Sequence Alignment
D002412:Cations; D005397:Fish Venoms; D007703:Peptidyl-Dipeptidase A
Angiotensin converting enzyme; Natterin 1; Venom