Potent histone deacetylase inhibitors built from trichostatin A and cyclic tetrapeptide antibiotics including trapoxin

Potent histone deacetylase inhibitors built from trichostatin A and cyclic tetrapeptide antibiotics including trapoxin

^*Department of Biotechnology, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan; ^‡Pharmaceuticals and Biotechnology Laboratory, Japan Energy Corporation, Toda-shi, Saitama 335-8502, Japan; ^§Department of Applied Chemistry, Faculty of Engineering, Kyushu Institute of Technology, Tobata-ku, Kitakyushu-shi 804-8550, Japan; ^¶Laboratoire de Biologie Moléculaire et Cellulaire de la Différenciation-Institut National de la Santé et de la Recherche Médicale U309, Equipe, chromatine et expression des gènes, Institut Albert Bonniot, Faculté de Médecine, Domaine de la Merci, 38706 La Tronche Cedex, France; and ^†Core Research for Evolutional Science and Technology Research Project, Japan Science and Technology Corporation, Saitama 332-0012, Japan

Edited by Paul A. Marks, Memorial Sloan-Kettering Cancer Center, New York, NY, and approved November 3, 2000 (received for review August 22, 2000)

Abstract

Trichostatin A (TSA) and trapoxin (TPX) are potent inhibitors of histone deacetylases (HDACs). TSA is proposed to block the catalytic reaction by chelating a zinc ion in the active-site pocket through its hydroxamic acid group. On the other hand, the epoxyketone is suggested to be the functional group of TPX capable of alkylating the enzyme. We synthesized a novel TPX analogue containing a hydroxamic acid instead of the epoxyketone. The hybrid compound cyclic hydroxamic acid-containing peptide (CHAP) 1 inhibited HDAC1 at low nanomolar concentrations. The HDAC1 inhibition by CHAP1 was reversible as it was by TSA, in contrast to the irreversible inhibition by TPX. CHAP with an aliphatic chain length of five, which corresponded to that of acetylated lysine, was stronger than those with other lengths. These results suggest that TPX is a substrate mimic and that the replacement of the epoxyketone with the hydroxamic acid converted TPX to an inhibitor chelating the zinc like TSA. Interestingly, HDAC6, but not HDAC1 or HDAC4, was resistant to TPX and CHAP1, whereas TSA inhibited these HDACs to a similar extent. HDAC6 inhibition by TPX at a high concentration was reversible, probably because HDAC6 is not alkylated by TPX. We further synthesized the counterparts of all known naturally occurring cyclic tetrapeptides containing the epoxyketone. HDAC1 was highly sensitive to all these CHAPs much more than HDAC6, indicating that the structure of the cyclic tetrapeptide framework affects the target enzyme specificity. These results suggest that CHAP is a unique lead to develop isoform-specific HDAC inhibitors.

Footnotes

↵ ‖ To whom reprint requests should be addressed at: Department of Biotechnology, Graduate School of Agriculture and Life Sciences, the University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan. E-mail: ayoshida{at}mail.ecc.u-tokyo.ac.jp.
This paper was submitted directly (Track II) to the PNAS office.
Article published online before print: Proc. Natl. Acad. Sci. USA, 10.1073/pnas.011405598.
Article and publication date are at www.pnas.org/cgi/doi/10.1073/pnas.011405598
Abbreviations:

Aoe,

(2S, 9S)-2-amino-9, 10-epoxy-8-oxodecanoic acid;

Asu,

α-aminosuberic acid;

CHAP,

cyclic hydroxamic-acid-containing peptide;

HDAC,

histone deacetylase;

HDLP,

histone deacetylase-like protein;

Pip,

pipecolic acid;

TPX,

trapoxin;

TSA,

trichostatin A;

Tyr(Me),

O-methyltyrosine;

AUT,

acid/urea/Triton