TABLE 3.

Metabolic enzymes involved in glutamylglutamate degradation by P. gingivalis ATCC 33277

Enzyme	Substrate	Electron carrier	Sp act (U/g of protein)a
Glutamylglutamate dipeptidase	Glutamylglutamate		21.4 ± 5.30
Glutamate dehydrogenase	Glutamate	NAD	1,130 ± 128
		NADP or MVoxb	ND
2-Oxoglutarate oxidoreductase	2-Oxoglutarate and CoA	NAD or NADP	ND
		MVox	11.6 ± 2.96
Succinate-semialdehyde dehydrogenase	Succinyl-CoA	NADH	788 ± 64.3
		NADPH or MVredc	ND
	Succinate-semialdehyde	NAD	1,280 ± 130
		NADP or MVox	ND
4-Hydroxybutyrate dehydrogenase	Succinate-semialdehyde	NADH	2,160 ± 226
		NADPH	330 ± 140
		MVred	ND
	4-Hydroxybutyrate	NAD	325 ± 175
		NADP	12.3 ± 2.90
		MVox	ND
4-Hydroxybutyrate to crotonoyl-CoA	4-Hydroxybutyrate and acetyl-CoA	MVred	148 ± 24.5
−Acetyl-CoA		MVred	11.7 ± 2.09
−Acetyl-CoA + ATP + CoA		MVred	10.8 ± 1.06
Butyryl-CoA oxidoreductase	Crotonoyl-CoA	NADH	1.64 ± 0.74
		NADPH	ND
		MVred	2,150 ± 132
	Butyryl-CoA	NAD, NADP, or MVox	ND

^aMean ± standard deviation obtained from three independent experiments. ND, not detected. 

^bMV_ox, oxidized methylviologen. 

^cMV_red, reduced methylviologen.