Isolation and Characterization of Rare Earth Element-Binding Protein in Roots of Maize

Abstract

Rare earth element-binding protein was isolated from maize, which was grown under greenhouse conditions and characterized in terms of molecular weight, amino acid composition, and ultraviolet absorption. The molecular weight of the maize protein was determined to be 183,000, with two distinct subunits of approximately molecular weights of 22,000 and 69,000, respectively. The protein is particularly rich in asparagine/aspartic acid, glutamine/glutamic acid, glycine, alanine, and leucine and contains 8.0% of covalently bound carbohydrate. The ultraviolet absorption of the protein is low at 280 nm and no change in the adsorption was observed with a change in pH. Compared to the unique features of the metallothioneins with a molecular weight of approximately 10,000, a high cysteine content of 30%, high absorption at 254 nm and a low absorption at 280 nm, and absorption change with pH, the REE-binding protein is unlikely to be plant metallothionein in nature. It was found that an almost twofold greater concentration was found for most of the REEs in the protein isolated from the maize with REE fertilizer use than that without REE fertilizer. This study suggests that the REE-binding protein is a glycoprotein and REEs can be firmly bound with the protein of maize roots.

Titanium as a Beneficial Element for Crop Production

“…REEs have been widely used in agriculture as plant growth stimulants (Hu et al, 2004; Tyler, 2004). Research on the roles of REEs identified a REE-binding protein in corn (Yuan et al, 2001), two from coral fern [ Dicranoptris dichotoma (Thunb.) Dernh.]…”

Manipulation of Dispersed Magnetic Beads for On-Chip Immunoassay

“…For a low-cost-fabrication process, organic transistors are also considered. A process using such transistors does not require vacuum chambers and mostly utilizes printing systems such as an inkjet 6) and gravure print, 7) and substrates for imprinting can be a polymer. However, the mobility of organic transistors is 1-10 cm 2 V À1 s À1 at most and this is 2 or more order of magnitude lower than that of a single crystal silicon device, 8) which directly influences the sensitivity of the Hall sensor.…”