Structure prediction and functional analysis of a non-permutated lectin from Dioclea grandiflora.
Legume lectins have been widely studied and applied for many purposes in the last few decades, but many of their physiological aspects remain elusive. The Diocleinae legume subtribe, which includes intensively explored lectins, such as ConA, presents an unusual and extensive post-translational process which results in minor alterations in protein structure, in turn making its function elusive. Despite previous reports about Diocleinae precursor activity, no structural or functional analyses have ever been carried out to understand the impacts of post-translational processing relative to lectin structure and binding specificity. Here we analyzed the functionality of a non glycosylated, recombinantly expressed lectin precursor from Dioclea grandiflora through inhibition assays, corroborating the experimental data with structural information generated by molecular modeling, docking calculations and molecular dynamics simulations. We demonstrate that Diocleinae precursors are active and share the same carbohydrate specificity as mature lectins. At the same time, however, subtle structural alterations were detected and mostly result in an "incomplete" functionality of the precursor, as consequence of an immature binding site and an unstructured tetramer interface, affecting carbohydrate binding and oligomer formation, respectively.
Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, 60455-970, Fortaleza, Ceará, Brazil; Departamento de Física, Universidade Federal do Ceará, 60455-760, Fortaleza, Ceará, Brazil. Electronic address: brunolopesdesousa@gmail.com.
Bruno Lopes
BL
de Sousa
Departamento de Engenharia de Pesca, Universidade Federal do Ceará, 60455-760, Fortaleza, Ceará, Brazil. Electronic address: naganocs@gmail.com.
Celso Shiniti
CS
Nagano
Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, 60455-970, Fortaleza, Ceará, Brazil; Centro de Ciências Biológicas e da Saúde, Universidade Federal do Oeste da Bahia, Rua Professor José Seabra de Lemos, 316, 47808-021, Barreiras, Bahia, Brazil. Electronic address: rafael.simoes@gmail.com.
Rafael da Conceição
RD
Simões
Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, 60455-970, Fortaleza, Ceará, Brazil. Electronic address: caetano.flh@gmail.com.
José Caetano
JC
Silva-Filho
Centro de Ciências Agrárias e Biológicas, Universidade do Vale do Acaraú, Rua Gerardo Rangel s/n, 62041-040, Sobral, Ceará, Brazil. Electronic address: rmaranguape@gmail.com.
Rodrigo Maranguape da Silva
RM
Cunha
Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, 60455-970, Fortaleza, Ceará, Brazil. Electronic address: jcajazeiras@gmail.com.
João Batista
JB
Cajazeiras
Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, 60455-970, Fortaleza, Ceará, Brazil. Electronic address: kyriasantiago@gmail.com.
Kyria Santiago
KS
do Nascimento
Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, 60455-970, Fortaleza, Ceará, Brazil. Electronic address: bscavada@gmail.com.
Benildo Sousa
BS
Cavada
D000595:Amino Acid Sequence; D001665:Binding Sites / Q000235:genetics; D002241:Carbohydrates / Q000737:chemistry; D019295:Computational Biology / Q000379:methods; D018360:Crystallography, X-Ray; D052598:Dioclea / Q000235:genetics / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics; D056004:Molecular Dynamics Simulation; D037121:Plant Lectins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D000072417:Protein Domains; D011498:Protein Precursors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry* / Q000378:metabolism; D020539:Sequence Analysis, Protein; D053719:Tandem Mass Spectrometry
D002241:Carbohydrates; C043014:Dioclea grandiflora lectin; D037121:Plant Lectins; D011498:Protein Precursors; D011994:Recombinant Proteins
Diocleinae; Functional analysis; Lectin; Precursor; Structure prediction