TABLE 1.

Phosphorylation of synthetic peptide substrates and Gsy2p^a

Substrate	Vmax (nmol min−1 ml−1)	Km (mM)	Vmax/Km (min−1)
Gsy2-654	8.2	2.7	3.0 × 10−3
Gsy2-667	0b	NDc	ND
Pho4-114	1.2	1.4	8.6 × 10−4
Gsy2p	32d	1.5 × 10−3e	11f

^aThe initial rate of phosphorylation of either synthetic peptides or Gsy2p was determined. The kinetic parameters for the synthetic peptides were obtained by fitting the data in Fig. 4A to the Michaelis-Menten equation by using nonlinear regression analysis. The parameters for Gsy2p phosphorylation were estimated from Fig. 3B, since Gsy2p phosphorylation did not follow hyperbolic kinetics. 

^bWithin the limits of the assay, no significant phosphorylation was detected. 

^cND, not determined. 

^dMeasured with 2 μM Pcl10p. 

^eThe concentration of Gsy2p required to achieve half the maximum rate. Estimated from Fig. 3B. 

^fEstimated from the initial slope of the graph in Fig. 3B.