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 sp...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 germinated in 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 Ⅰ from 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.展开更多
文摘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 germinated in 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 Ⅰ from 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.
