Physico-chemical characteristics and primary structure of an affinity-purified α-D-galactose-specific, jacalin-related lectin from the latex of mulberry (Morus indica).
An α-D-galactose specific lectin belonging to the family of jacalin-related lectins (JRL) has been purified by affinity chromatography on cross-linked guar-gum. Mass spectrometric data revealed that the protein harbors two chains like all the members of galactose-specific jacalin-related lectins (gJRL). De novo sequencing of proteolytic peptides demonstrated that the heavier chain consists of 133 amino acids and the lighter chain comprises of 21 or 24 amino acids. The heavier chain contains one N-glycosylation site (Asn47) occupied with either pauci-mannose type [GlcNAc2(Fuc)Man3(Xyl)] or complex type [GlcNAc2(Fuc)Man3(Xyl)GlcNAc(Fuc)Gal] N-glycans. Circular dichroism spectroscopy indicated that the secondary structure of the lectin is predominantly made up of β-sheets, and differential scanning calorimetry revealed a thermal denaturation temperature of 77.6 °C. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) cell viability assays on MCF-7 and MDCK cells showed that the lectin is highly cytotoxic towards both cell lines when dosed at micromolar concentrations, suggesting that it may play a role in the defense mechanism of the plant.
School of Chemistry, University of Hyderabad, Hyderabad 500 046, India.
Debparna
D
Datta
Institute for Hygiene, University of Münster, 48149 Münster, Germany.
Gottfried
G
Pohlentz
Institute for Hygiene, University of Münster, 48149 Münster, Germany.
Mona
M
Schulte
Institute of Plant Biotechnology and Biology, University of Münster, 48149 Münster, Germany.
Mathias
M
Kaiser
Institute of Plant Biotechnology and Biology, University of Münster, 48149 Münster, Germany.
Francisco M
FM
Goycoolea
Institute for Hygiene, University of Münster, 48149 Münster, Germany.
Johannes
J
Müthing
Institute for Hygiene, University of Münster, 48149 Münster, Germany.
Michael
M
Mormann
School of Chemistry, University of Hyderabad, Hyderabad 500 046, India. Electronic address: mjswamy@uohyd.ac.in.
Musti J
MJ
Swamy
D000818:Animals; D002152:Calorimetry, Differential Scanning; D002846:Chromatography, Affinity; D002942:Circular Dichroism; D004285:Dogs; D005260:Female; D005690:Galactose / Q000737:chemistry*; D006801:Humans; D061986:MCF-7 Cells; D061985:Madin Darby Canine Kidney Cells; D013058:Mass Spectrometry; D031625:Morus / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry; D037121:Plant Lectins / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation; D017433:Protein Structure, Secondary
D010455:Peptides; D037121:Plant Lectins; C043696:jacalin; D005690:Galactose
Agglutinin; Cytotoxicity; Mass spectrometry; Pauci-mannose-type glycan; gJRL