원저 ( Original articles ) ; 단백질 소수성 측정 방법에 관한 연구 형광법 및 소수성 분획법

The effective hydrophobicity of different proteins, BSA, lysozyme, α-chymotrypsin, trypsin, β-lactoglobulin, myoglobin, ovalbumin, casein, soybean protein 7S and 11S fractions, rapeseed protein isolate, were determined by fluorometric method using ANS as chromophore and hydrophobic partitioning technique using polyethylene glycol) and PEG-palmitate bi-phasic system. The optimum excitation and emission wave lengthes for the measurement of relative fluorescence intensity of protein-ANS complex were 380 ㎚ and 465 ㎚, respectively. The relative intensity was influenced by the concentration indicating high level of hydorphobicity, whereas those of ovalbum and soybean protein 11S fraction were low. The hydrophobic partition coefficient (△logK) gave similar results as shown in fluorometric method. The △log K of BSA and casein were 1.625 and 1.660, respectively, while those of ovalbumin and soybean 11s fraction were 0.216 and 0.170. The changes in the effective hydrophobicity of proteins in solutions at different pH, ionic strength and heat treatment, could be related to the structural characteristic of the proteins.