Porcine Pancreatic α-Amylase and its Isoforms: Purification and Kinetic Studies

Figures & data

Figure 1 Elution profile of porcine pancreatic alpha amylase on DEAE—cellulose column.

Table 1 Kinetic constants of PPA, PPA-I, and PPA-II for cereal and millet starches. (K_m and V_max)

Starches	PPA		PPA-I		PPA-II
	Km	Vmax	Km	Vmax	Km	Vmax
Ragi	2.3	4149	2.5	4201	1.4	4149
Rice	0.8	2841	1.3	2740	1.0	2755
Wheat	1.0	3571	1.8	3125	1.5	3571
Maize	3.3	6212	2.5	3571	2.9	5102
Km (%) ; Vmax (U/mg protein). Mean values of duplicate analysis.

Figure 2 (a) pH optima of PPA, PPA-I and PPA-II; (b) Temperature optima of PPA, PPA-I and PPA-II.

Figure 3 pH stability of PPA and its isoforms. (a) PPA; (b) PPA-I; (c) PPA-II.

Figure 4 Effect of temperature on stability of PPA, PPA-I and PPA-II.

Table 2 Effect of metal ions on the activities of PPA, PPA-I and PPA-II

Salts (5mM)	PPA	PPA-I	PPA-II
Control	100	100	100
CaCl2	114.9	58.6	48.9
BaCl2	108.4	14.1	0.8
CoCl2	105.9	21.2	2.6
MgCl2	111.6	18.8	25.5
ZnCl2	15.5	12.6	5.2
Cucl2	0.7	0.3	0.4
AlCl3	0	0	0
HgCl2	0	0	0
Mean values of triplicate analysis.

Figure 5 (a) Effect of citric acid on the activities of PPA and its isoforms; (b) Effect of oxalic acid on the activities of PPA and its isoforms.

Figure 6 Effect of EDTA on PPA and its isoforms.

Figure 7(i) ESI-MS spectra of maltooligosacharides obtained by PPA digestion of starches: (a) ragi; (b) rice; (c) wheat; (d) maize.

Figure 7(ii) ESI-MS spectra of maltooligosacharides obtained by PPA-I digestion of starches: (a) ragi; (b) rice; (c) wheat; (d) maize.

Figure 7(iii) ESI-MS spectra of maltooligosacharides obtained by PPA-II digestion of starches: (a) ragi; (b) rice; (c) wheat; (d) maize.