Role of Spermidine in the Ice–Nucleating Activity of the EIM fromErwinia uredovoraKUIN-3

The Control of the Production and Secretion of Extracellular Ice-nucleating Material of Erwinia uredovora KUIN-3.

“…Judging from the necessity of Lys for this secretion, we could predict the optimum conditions for EIM including shape, surface charge and hydrophobicity. We reported that spermidine (SPD) on the EIM surface can control the charge and hydrophobicity of the EIM surface for the optimum structure with a high level of ice-nucleating activity (Kawahara et al, 1994). In general, a part of Lys can metabolize to CAD, which was one of the polyamines, by catalyzing Lys decarboxylase (Igarashi et al, 1986).…”

“…The charges on the surfaces of the cell and EIM were measured using a previously described method with 5-N-hexadecanoyl-aminofluorescein (Kawahara et al, 1994) . The ratio of fluorescence intensity at an emission of 495 nm was measured at an excitation of 495 nm.…”