Poster: Education

Abs # 21: A serine protease from germinated wheat seeds

Presenter:	Fahmy, Afaf S., saleh38@hotmail.com
Authors	Fahmy, Afaf S. (A)   Mohamed, Saleh A. (A)
Affiliations:	(A): National Research Centre

A new method for the purification of a serine protease from wheat Triticum aestivum (cv. Giza 164) has been developed. It consists of ion-exchange and gel filtration. The molecular mass of the enzyme was 58 kDa by SDS/PAGE under reducing conditions and 57 kDa by gel filtration on a Sepharose 6B column. The enzyme had isoelectric point and pH optimum at 4.2 and 4.5, respectively. The substrate specificity of the enzyme was studied by the use of synthesis and natural substrates, azocasein, azoalbumin, hemoglobin, casein, gelatin and egg albumin. The enzyme appears to prefer azocasein with Km 2 mg azocasein / ml. The enzyme had a temperature optimum at 50 oC with heat stability up to 40 oC. While Co2+ and Mg2+ accelerated the enzyme activity by 54% and 56%, respectively, Ca2+ and Ni2+ had very little effect. The enzyme was strongly inhibited by PMSF (phenylmethylsulphonyl flouride), but not by the other protease inhibitors, suggesting that the enzyme is a serine protease. From the results it can be concluded from the characterization that the T. aestivum serine protease may be suitable for food processing.