Del Prete Sonia, Vullo Daniela, De Luca Viviana, Carginale Vincenzo, di Fonzo Pietro, Osman Sameh M, AlOthman Zeid, Supuran Claudiu T, Capasso Clemente
Istituto di Bioscienze e Biorisorse, CNR, Via Pietro Castellino 111, Napoli, Italy; Università degli Studi di Firenze, Dipartimento Di Chimica, Laboratorio di Chimica Bioinorganica, Polo Scientifico, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy.
Università degli Studi di Firenze, Dipartimento Di Chimica, Laboratorio di Chimica Bioinorganica, Polo Scientifico, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy.
Bioorg Med Chem. 2016 Aug 15;24(16):3413-7. doi: 10.1016/j.bmc.2016.05.029. Epub 2016 May 18.
Among the numerous metalloenzymes known to date, carbonic anhydrase (CA, EC 4.2.1.1) was the first zinc containing one, being discovered decades ago. CA is a hydro-lyase, which catalyzes the following hydration-dehydration reaction: CO2+H2O⇋HCO3(-)+H(+). Several CA classes are presently known, including the α-, β-, γ-, δ-, ζ- and η-CAs. In prokaryotes, the existence of genes encoding CAs from at least three classes (α-, β- and γ-class) suggests that these enzymes play a key role in the physiology of these organisms. In many bacteria CAs are essential for the life cycle of microbes and their inhibition leads to growth impairment or growth defects of the pathogen. CAs thus started to be investigated in detail in bacteria, fungi and protozoa with the aim to identify antiinfectives with a novel mechanism of action. Here, we investigated the catalytic activity, biochemical properties and anion inhibition profiles of the three CAs from the bacterial pathogen Vibrio cholera, VchCA, VchCAβ and VchCAγ. The three enzymes are efficient catalysts for CO2 hydration, with kcat values ranging between (3.4-8.23)×10(5)s(-1) and kcat/KM of (4.1-7.0)×10(7)M(-1)s(-1). A set of inorganic anions and small molecules was investigated for inhibition of these enzymes. The most potent VchCAγ inhibitors were N,N-diethyldithiocarbamate, sulfamate, sulfamide, phenylboronic acid and phenylarsonic acid, with KI values ranging between 44 and 91μM.
在迄今为止已知的众多金属酶中，碳酸酐酶（CA，EC 4.2.1.1）是最早发现的含锌酶，它是在数十年前被发现的。CA是一种水解酶，催化以下水合 - 脱水反应：CO2 + H2O⇋HCO3(-) + H(+)。目前已知有几类CA，包括α -、β -、γ -、δ -、ζ - 和η - CA。在原核生物中，至少三类（α -、β - 和γ - 类）编码CA的基因的存在表明这些酶在这些生物体的生理过程中起关键作用。在许多细菌中，CA对微生物的生命周期至关重要，其抑制会导致病原体生长受损或生长缺陷。因此，人们开始在细菌、真菌和原生动物中详细研究CA，目的是鉴定具有新作用机制的抗感染药物。在此，我们研究了细菌病原体霍乱弧菌的三种CA，即VchCA、VchCAβ和VchCAγ的催化活性、生化特性和阴离子抑制谱。这三种酶都是CO2水合的有效催化剂，kcat值在(3.4 - 8.23)×10(5)s(-1)之间，kcat/KM为(4.1 - 7.0)×10(7)M(-1)s(-1)。研究了一组无机阴离子和小分子对这些酶的抑制作用。最有效的VchCAγ抑制剂是N，N - 二乙基二硫代氨基甲酸盐、氨基磺酸盐、磺胺、苯硼酸和苯胂酸，KI值在44至91μM之间。
