| Abstract
| - Starch granule-bound proteins in endosperms of common wheat(Triticum aestivum L.) included atleast one major protein with a molecular weight of 61 000 (Wxprotein: starch granule-bound starchsynthase) and six minor proteins with molecular weights of 115 000,108 000, 100 000, 92 000, 80 000,and 15 000 (SGP-A1, -D1, -B1, -2, -3, and friabilin, respectively).Peptide mapping of SGP-A1, -D1,-B1, -2, and -3 indicated that the primary structures of SGP-A1, -D1,and -B1 are highly homologousbut differ considerably from that of SGP-2. The internal sequencesof peptides obtained from SGP-D1, -2, and -3 showed that SGP-D1 and SGP-3 are structurally similar torice soluble starch synthase,whereas SGP-2 has homology to rice starch branching enzyme 3.These results are in agreementwith results of immunological and enzymatic studies suggesting thatSGP-A1, -D1, -B1, and -3 aretypes of soluble starch synthases and that SGP-2 is a starch branchingenzyme. Keywords: Starch granule-bound protein; amino acid sequence; wheat(Triticum aestivum L.)
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