Human aspartate/asparagine-β-hydroxylase (AspH) is a 2-oxoglutarate (2OG) dependent oxygenase that catalyses the hydroxylation of Asp/Asn-residues of epidermal growth factor-like domains (EGFDs). AspH is reported to be upregulated on the cell surface of invasive cancer cells in a manner distinguishing healthy from cancer cells. We report studies on the effect of small-molecule active pharmaceutical ingredients (APIs) of human cancer therapeutics on the catalytic activity of AspH using a high-throughput mass spectrometry (MS)-based inhibition assay. Human B-cell lymphoma-2 (Bcl-2)-protein inhibitors, including the (R)-enantiomer of the natural product gossypol, were observed to efficiently inhibit AspH, as does the antitumor antibiotic bleomycin A₂. The results may help in the design of AspH inhibitors with the potential of increased selectivity compared to the previously identified Fe(II)-chelating or 2OG-competitive inhibitors. With regard to the clinical use of bleomycin A₂ and of the Bcl-2 inhibitor venetoclax, the results suggest that possible side-effects mediated through the inhibition of AspH and other 2OG oxygenases should be considered.

人天冬氨酸/天冬酰胺-β-羟化酶 (AspH) 是一种 2-氧代戊二酸 (2OG) 依赖性加氧酶，可催化表皮生长因子样结构域 (EGFD) 的 Asp/Asn 残基的羟基化。据报道，AspH 在侵袭性癌细胞的细胞表面上以区分健康细胞和癌细胞的方式上调。我们使用基于高通量质谱 (MS) 的抑制测定报告了关于人类癌症治疗剂的小分子活性药物成分 (API) 对 AspH 催化活性影响的研究。观察到人类 B 细胞淋巴瘤-2 (Bcl-2)-蛋白抑制剂，包括天然产物棉酚的 ( R )-对映异构体，可有效抑制 AspH，抗肿瘤抗生素博莱霉素 A _{2也是如此}. 与先前确定的 Fe(II) 螯合或 2OG 竞争性抑制剂相比，该结果可能有助于设计具有更高选择性的 AspH 抑制剂。关于博来霉素 A ₂和 Bcl-2 抑制剂 venetoclax 的临床应用，结果表明应考虑通过抑制 AspH 和其他 2OG 加氧酶介导的可能副作用。