Gayler K R, Kolivas S, Macfarlane A J, Lilley G G, Baldi M, Blagrove R J, Johnson E D
Russell Grimwade School of Biochemistry, Parkville, VIC, Australia.
Plant Mol Biol. 1990 Dec;15(6):879-93. doi: 10.1007/BF00039427.
The biosynthesis of conglutin delta has been studied in developing cotyledons of Lupinus angustifolius L. Precursors of conglutin delta formed the major sink for [35S]-cysteine incorporated by developing lupin cotyledons, and these precursors were rapidly sequestered into the endoplasmic reticulum. The sequence of a cDNA clone coding for one such precursor of conglutin delta was determined. The structure of the precursor polypeptide for conglutin delta predicted from the cDNA sequence contained an N-terminal leader peptide of 22 amino acids directly preceding a subunit polypeptide of Mr 4520, together with a linking region of 13 amino acids and a subunit polypeptide of Mr 9558 at the C-terminus. The amino acid sequence predicted from the cDNA sequence showed minor variations from that established by sequencing of the protein purified from mature dried seeds (Lilley and Inglis, 1986). These were consistent with the existence of a multi-gene family coding for conglutin delta. Comparison of the sequences of conglutin delta with those of other 2S storage proteins showed that the cysteines involved in internal disulphide bridges between the mature subunits of conglutin delta, were maintained throughout this family of proteins but that little else was conserved either at the protein or DNA level.
已对窄叶羽扇豆发育中的子叶中凝集素δ的生物合成进行了研究。凝集素δ的前体构成了发育中的羽扇豆种子吸收[35S]-半胱氨酸的主要途径，并且这些前体迅速被隔离到内质网中。确定了编码凝集素δ的一种此类前体的cDNA克隆的序列。从cDNA序列预测的凝集素δ前体多肽的结构包含一个由22个氨基酸组成的N端前导肽，该前导肽直接位于一个Mr 4520的亚基多肽之前，以及一个由13个氨基酸组成的连接区域和一个位于C端的Mr 9558的亚基多肽。从cDNA序列预测的氨基酸序列与从成熟干燥种子中纯化的蛋白质测序确定的序列略有不同（利利和英格利斯，1986年）。这些与存在编码凝集素δ的多基因家族一致。将凝集素δ的序列与其他2S贮藏蛋白的序列进行比较表明，参与凝集素δ成熟亚基之间内部二硫键形成的半胱氨酸在整个蛋白质家族中得以保留，但在蛋白质或DNA水平上几乎没有其他保守的地方。
