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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Biochemical characterization and low-resolution SAXS structure of an exopolygalacturonase from Bacillus licheniformis

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Evangelista, Danilo Elton [1] ; de Araujo, Evandro A. [1] ; Oliveira Neto, Mario [2] ; Seiki Kadowaki, Marco Antonio [1] ; Polikarpov, Igor [1]
Total Authors: 5
[1] Univ Sao Paulo, Inst Fis Sao Carlos, Ave Trabalhador Saocarlense 400, BR-13566590 Sao Carlos, SP - Brazil
[2] Univ Estadual Paulista Julio De Mesquita Filho UN, Inst Biociencias, Dept Fis & Biofis, BR-18618970 Botucatu, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: NEW BIOTECHNOLOGY; v. 40, n. B, p. 268-274, JAN 25 2017.
Web of Science Citations: 3

Among the structural polymers present in the plant cell wall, pectin is the main component of the middle lamella. This heterogeneous polysaccharide has an alpha-1,4 galacturonic acid backbone, which can be broken by the enzymatic action of pectinases, such as exo-polygalacturonases, that sequentially cleave pectin from the nonreducing ends, releasing mono or di-galacturonic acid residues. Constant demand for pectinases that better suit industrial requirements has motivated identification and characterization of novel enzymes from diverse sources. Bacillus licheniformis has been used as an important source for bioprospection of several industrial biomolecules, such as surfactants and enzymes, including pectate lyases. Here we cloned, expressed, purified, and biochemically and structurally characterized an exo-polygalacturonase from B. licheniformis (BlExoPG). Its low-resolution molecular envelope was derived from experimental small-angle scattering data (SAXS). Our experimental data revealed that BlExoPG is a monomeric enzyme with optimum pH at 6.5 and optimal temperature of approximately 60 degrees C, at which it has considerable stability over the broad pH range from 5 to 10. After incubation of the enzyme for 30 min at pH ranging from 5 to 10, no significant loss of the original enzyme activity was observed. Furthermore, the enzyme maintained residual activity of greater than 80% at 50 degrees C after 15 h of incubation. BlExoPG is more active against polygalacturonic acid as compared to methylated pectin, liberating mono galacturonic acid as a unique product. Its enzymatic parameters are V-max = 4.18 mu M. s(-1), K-m = 3.25 mgmL(-1) and k(cat)= 2.58 s(-1). (AU)

FAPESP's process: 15/13684-0 - Structural and functional studies of enzymes that participate in complex carbohydrates synthesis and degradation
Grantee:Igor Polikarpov
Support type: Research Projects - Thematic Grants
FAPESP's process: 11/20505-4 - Two important classes of glycosyl hydrolases: functional studies and structural analysis
Grantee:Marco Antonio Seiki Kadowaki
Support type: Scholarships in Brazil - Post-Doctorate