Seedlings of the gymnosperm,Pinus edulis Engelm., have a distinctive pattern of starch accumulation following germination; however, the enzymes involved in starch synthesis have not been studied in gymnosperm species. In this study, enzymes and starch were extracted from P. edulis seedlings germinatedin the dark at room temperature. Granule bound proteins of 58 kD and 91 kD were recognized by a pea SS Ⅱ antiserum. The 58 kD granule bound protein was purified and identified as granule bound starch synthase Ⅰ by alignment of the N terminal sequence with that of granule bound starch synthase Ⅰfrom several angiosperms.Elution of soluble starch synthase activity from a DEAE Sepharose column showed two starch synthase activity peaks, indicating at least two isoforms of soluble starch synthases. Primer affinities of soluble starch synthases were investigated. Glycogen from rabbit was the best primer for soluble starch synthase. The enzymological properties of Pinus starch synthases appear to be similar to those reported for angiosperms.
萌发后食松幼苗淀粉粒结合与可溶性淀粉合酶的研究*
严海燕1** J.B.MUROHY 2
（1. 郑州大学生物工程系，郑州450052；2. Departnebt of Horticure,Unixersity of Arkansas,Fayetteville AR 72701,USA）
摘要： 裸子植物食松(Pinus edulis Engelm.)幼苗在萌发后具有淀粉积累的独特特征,而淀粉合酶在裸子植物中尚未有研究.这项研究对在室温下暗中萌发的食松幼苗的淀粉合酶进行了提取和研究,结果显示: 58 kD和91 kD的淀粉粒结合蛋白均为豌豆淀粉合酶Ⅱ抗体所识别. 58 kD淀粉粒结合蛋白被纯化出来, 其N端序列与其他几种被子植物淀粉粒结合的淀粉合酶Ⅰ的N端序列有很高的相似性,并与豌豆、大麦、马铃薯淀粉粒结合淀粉合酶Ⅰ有免疫相似性,被鉴定为淀粉粒结合的淀粉合酶Ⅰ.从DEAE-Sepharose 柱上洗脱出来的可溶性淀粉合酶表现出两个淀粉合酶活性峰,表明至少有两类可溶性淀粉合酶同工酶.对可溶性淀粉合酶的前体亲和特性进行了研究.以兔肝糖原为前体时, 可溶性淀粉合酶的亲和性最高.裸子植物淀粉合酶的酶学特性表现与已研究的被子植物相似.
关键词： 淀粉合酶；裸子植物；淀粉粒结合的淀粉合酶；食松
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