ISOLASI DAN KARAKTERISASI PROTEIN SORGUM DAN PENINGKATAN KARAKTER JEJARING PROTEIN SORGUM DENGAN PENAMBAHAN TRANSGLUTAMINASE ATAU GLUKOSA-OKSIDASE

Abstract

Abstract

The objectives were to fractionate protein of the flour of Zh-30 sorghum strain using five types of solvents, isolate crude transglutaminase of Bacillus subtilis spores. The protein fractions were analyzed for protein content and molecular weight by SDS-PAGE and evaluated for protein-network formation by crude transglutaminase and glucose-oxidase. The result showed flour protein of the sorghum Zh-30 strain consisted of five classes of proteins with a ratio of albumin, globuline, kafirin 1, gluteline and kafirin 2 or cross-linked kafirin 11:11:42:7:29respectively. Kafirin 1 content was 36.01%, kafirin 2 24.79%, gluteline 22.15%, globuline 12.81% and albumin 4.24% of total protein. Molecular weight of each protein fraction of the sorghum flour Zh-30 strain was respectively albumin 69.9 kDa, kafirin 1 which consisted α1-kafirin 22.4 kDa and α2-kafirin 23.5 kDa, globuline 121 kDa, gluteline 15.5 kDa and kafirin 2 which consisted of α1-kafirin 16.2 kDa, α2-kafirin 23.5 kDa, β-kafirin 24.6 kDa and γ-kafirin 53.6 kDa. No protein network was found due to transglutaminase activity on BSA nor sorghum protein fractions; however protein networking was established when the glutelin fraction was treated with glucose-oxidase (MW 69 kDa from 15.5 kDa).

Keywords: sorghum protein, protein network, crude transglutaminase, glucose-oxidase.