Crystallization and preliminary structural studies of champedak galactose-binding lectin

Abstract

Galactose-binding lectin from champedak (Artocarpus integer) consists of two chains: alpha and beta (133 and 21 amino acids, respectively). It has been shown to recognize and bind to carbohydrates involved in IgA and C1 inhibitor molecules. The protein was purified and crystallized at 293 K. Crystals were observed in two space groups, P2(1) and P2(1)2(1)2, and diffracted to 1.65 and 2.6 A, respectively.

Structures and binding specificity of galactose- and mannose-binding lectins from champedak: differences from jackfruit lectins

“…As this crystal was the only one exhibiting space group P2 1 and all others, including those reported here, exhibited P2 1 2 1 2, it was initially assumed that the monoclinic space group was due to accidental annealing during crystal transfer (Gabrielsen et al, 2009). Superposing the eight subunits of the monoclinic space group onto the content of the orthorhombic cell, the extraneous monoclinic subunits are positioned where the symmetry-related copies of the P2 1 2 1 2 structure are located.…”

“…The proteins were isolated and crystallized using previously published protocols (Hashim et al, 1991(Hashim et al, , 1993Gabrielsen et al, 2009Gabrielsen et al, , 2010. Data collection and processing have been discussed elsewhere (Gabrielsen et al, 2009(Gabrielsen et al, , 2010. The resolution was based on the statistics following scaling and in particular based on the poor completeness and merging statistics at higher resolution.…”

“…‡ R free is calculated as R work , using 5% of the data excluded from refinement. § Published elsewhere (Gabrielsen et al, 2009). } Published elsewhere (Gabrielsen et al, 2010).…”

Application of champedak mannose‐binding lectin in the glycoproteomic profiling of serum samples unmasks reduced expression of alpha‐2 macroglobulin and complement factor B in patients with nasopharyngeal carcinoma

“…Although the champedak galactose-binding (CGB) lectin recognizes the O-glycans [12,13], the CMB lectin binds to the N-glycans of glycoproteins [10,11]. In this study, the CMB lectin was purified from the crude extracts of the champedak seeds using sequential immobilized galactose and mannose affinity chromatography, as reported previously [12].…”

Crystallization and initial X-ray diffraction analysis of a mannose-binding lectin from champedak

“…Briefly, 80 g powdered champedak seeds was suspended in phosphate-buffered saline (PBS) pH 7.4 at 277 K for 24 h and the resulting supernatant was subjected to precipitation with 60% ammonium sulfate. The pellet containing the crude extract was collected, dissolved in cold PBS and dialysed against several changes of PBS for 48 h. The crude champedak seed extract was then subjected to galactose affinity chromatography to remove CGB (Gabrielsen et al, 2009), which is also present in the champedak seeds. The flowthrough fractions were pooled, applied onto a mannose Sepharose 4B affinity column and washed extensively with PBS until the absorbance reached baseline.…”