Table 1.

Enzymatic properties of purified Vp16 PDF and comparison with other PDFs.

PDF enzyme	k cat (s−1)a	K m (mM)a	k cat/K m (M−1.s−1)a
Ni-E. coli PDF1Ba	34–144	0.2–3.8	15,355–86,000
Ni-T. thermophilus PDF1Bc	27 ± 3	2.3 ± 0.5	11,739 ± 2,500
Synechocystis PCC PDF1Bd	150–250	1–2	88–313
Ni-A. thaliana PDF1Bb	75 ± 15	5.6 ± 1.9	13,300 ± 1,500
Ni-Vp16 PDF1B	5.3–27.4	1–2.9	2,286–9448
Synechococcus phage S-SSM7 PDF4d	433–800	0.3–1.3	449–2,204
Zn-A. thaliana PDF1Ab	22 ± 2	0.3 ± 0.1	88,000 ± 150
Ni-H. sapiens PDFIAe	0.26 ± 0.04	3.6 ± 0.9	72 ± 7
Ni-B. stearotermophilus PDF2c	1007 ± 191	4.1 ± 1.2	245,000 ± 20,000
Ni-S. agalactiae PDF2f	50 ± 3	1.2 ± 0.8	41,993
Ni-P. falciparum PDF3g	ND	ND	13,700 ± 1,000
Zn-T. brucei PDF3h	ND	ND	8

^aKinetic constants were determined using the coupled assay, as indicated in Materials and Methods, using substrates Fo-Met-Ala-Ser, Fo-Met-Lys-Leu, Fo-Met-Pro-Ala, Fo-Met-Ser-Asn, Fo-Met-Thr-Thr, Fo-Met-Ala-Lys when tested Vp 16 PDF1B and Ni-E. coli PDF1B.

^bData for E. coli and Arabidopsis thaliana PDF1Bs were taken from ref. 26.

^cData for Thermus thermophilus PDF1B and Bacillus stearothermophilus PDF2 were taken from refs ^{20, 28} and ³⁷.

^dData were taken from ref. 16, substrates used: Fo-Met-Thr-Ser-Ile, Fo-Met-Leu-Ile-Ser, Fo-Met-Thr-Thr-Ala, Fo-Met-Ala-Lys-Lys, Fo-Met-Ala-Arg-Ile, Fo-Met- Ser-Arg-Val.

^eData for Homo sapiens PDF1A were taken from ref. 38.

^fData for Streptococcus agalactiae PDF2 were taken from ref. 28.

^gData for Plasmodium falciparum PDF3 were taken from ref. 27, substrate used: Fo-Met-Leu-p-nitroanilide.

^hFor Trypanosoma brucei PDF3 Data were taken from ref. 39.

ND, not determined.

Ni- or Zn indicates Ni²⁺- or Zn²⁺-containing PDFs.