Sucrose-density gradient ultracentrifugation was used for determination of sedimentation constant (S20,w) and approximate molecular weight (PMW) of UDPG pyrophosphorylase form bamboo shoot in heterogeneous form. By enzyme assay, at least two components were found. The S20,w and PMW of these two components were 3.36-3.32; 39,500-37,600 and 4.58-4.53; 63,000-60,700 respectively.
The possible explanations were association-dissociation of the enzyme mo;ecule or interaction of enzyme molecule with some non-enzymic or non-protein components. 本試驗乃先由綠竹筍(bamboo shoot)中抽取UDPG pyrophosphorylase，並經部分純化。進而利用蔗糖密度梯度超速離心法，以測定此酵素之沉降常數(S20,w) 及近似分子量。由酵素活性檢驗顯示，竹筍中之此酵素經離心後可得到至少兩個不同的成分。經對照標準曲線測得其沉降常數及近似分子量約分別為3.36~3.32；39,500~37,600及4，58~4.53； 63,000~60,700。最後就此現象加以討論。