Structural and functional studies on the cyanide degrading enzyme CynD from Bacillus safensis PER-URP-08

• Grant number: 22/00943-1
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: August 01, 2022
• End date: July 31, 2025
• Field of knowledge: Biological Sciences - Biochemistry - Chemistry of Macromolecules
• Principal Investigator: Shaker Chuck Farah
• Grantee: Santiago Justo Arevalo
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Cyanide is widely used in industries due to its high affinity for metals. This characteristic is at the same time responsible for the potent toxicity of this compound. Thus, industries have to reduce the cyanide concentration from wastewater before its final disposal. Physical, chemical and biological methods have been developed to achieve this goal, but knowledge about metabolic pathways and the action of enzymes involved in cyanide degradation is still scarce. The bacterium Bacillus safensis PER-URP-08 was isolated from mine wastewater from Peru and studied by our groups in Peru and Brazil with the objective to develop an environmental-friendly and effective cyanide-removal process. Our preliminary results include complete genome sequencing and the demonstration that an encoded cyanide dihydratase (CynD) is likely the enzyme responsible for cyanide degradation and that CynD expression is strongly induced in the presence of cyanide. CynD from this strain was cloned, expressed in E. coli, purified and its enzymatic activity was characterized. SEC-MALS and electron microscopy analysis of purified CynD shows that the enzyme forms large helical structures at pH 8 and less extensively polymerized filaments at higher pHs. CynD of this strain was active up to pH 9, different from other enzymes of this class. This is an advantageous characteristic since it would allow cyanide degradation to be carried out under conditions that minimize HCN volatilization (pKa = 9.2) at high pH. The main objective of this project, therefore, is to employ cryo-electron microscopy to determine the structure of CynD at different pHs in order to understand the structural basis of its pH-dependent activity. This could potentially lead to the optimization of this enzyme and its eventual application in the decontamination of industrial wastes containing cyanide. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

JUSTO AREVALO, SANTIAGO; URIBE CALAMPA, CARMEN SOFIA; JIMENEZ SILVA, CINTHY; QUINONES AGUILAR, MAURO; BOUCKAERT, REMCO; REBELLO PINHO, JOAO RENATO. Phylodynamic of SARS-CoV-2 during the second wave of COVID-19 in Peru. NATURE COMMUNICATIONS, v. 14, n. 1, p. 13-pg., 2023-06-15. (15/13318-4, 22/00943-1)

AREVALO, SANTIAGO JUSTO; CASTILLO-CHAVEZ, ADRIANA; CALAMPA, CARMEN SOFIA URIBE; SIFUENTES, DANIELA ZAPATA; HUALLPA, CESAR J.; BIANCHI, GIANFRANCO LANDA; CASAS, ROMINA GARAVITO-SALINI; AGUILAR, MAURO QUINONES; CHAVARRIA, ROBERTO PINEDA. What do we know about the function of SARS-CoV-2 proteins?. FRONTIERS IN IMMUNOLOGY, v. 14, p. 14-pg., 2023-09-18. (15/13318-4, 22/00943-1)