Recent advances in poly phosphate kinase (PPK) and the construction of PPK-mediated ATP regeneration system / 生物工程学报

Adenosine triphosphate (ATP) regeneration systems are essential for efficient biocatalytic phosphoryl transfer reactions. Polyphosphate kinase (PPK) is a versatile enzyme that can transfer phosphate groups among adenosine monophosphate (AMP), adenosine diphosphate (ADP), ATP, and polyphosphate (Poly P). Utilization of PPK is an attractive solution to address the problem of ATP regeneration due to its ability to use a variety of inexpensive and stable Poly P salts as phosphate group donors. This review comprehensively summarizes the structural characteristics and catalytic mechanisms of different types of PPKs, as well as the variations in enzyme activity, catalytic efficiency, stability, and coenzyme preference observed in PPKs from different sources. Moreover, recent advances in PPK-mediated ATP regeneration systems and protein engineering of wild-type PPK are summarized.

Preclinical and early clinical studies of a novel compound SYHA1813 that efficiently crosses the blood-brain barrier and exhibits potent activity against glioblastoma

Glioblastoma (GBM) is the most common and aggressive malignant brain tumor in adults and is poorly controlled. Previous studies have shown that both macrophages and angiogenesis play significant roles in GBM progression, and co-targeting of CSF1R and VEGFR is likely to be an effective strategy for GBM treatment. Therefore, this study developed a novel and selective inhibitor of CSF1R and VEGFR, SYHA1813, possessing potent antitumor activity against GBM. SYHA1813 inhibited VEGFR and CSF1R kinase activities with high potency and selectivity and thus blocked the cell viability of HUVECs and macrophages and exhibited anti-angiogenetic effects both in vitro and in vivo. SYHA1813 also displayed potent in vivo antitumor activity against GBM in immune-competent and immune-deficient mouse models, including temozolomide (TMZ) insensitive tumors. Notably, SYHA1813 could penetrate the blood-brain barrier (BBB) and prolong the survival time of mice bearing intracranial GBM xenografts. Moreover, SYHA1813 treatment resulted in a synergistic antitumor efficacy in combination with the PD-1 antibody. As a clinical proof of concept, SYHA1813 achieved confirmed responses in patients with recurrent GBM in an ongoing first-in-human phase I trial. The data of this study support the rationale for an ongoing phase I clinical study (ChiCTR2100045380).

Formate dehydrogenase and its application in biomanufacturing of chiral chemicals / 生物工程学报

The redox biosynthesis system has important applications in green biomanufacturing of chiral compounds. Formate dehydrogenase (FDH) catalyzes the oxidation of formate into carbon dioxide, which is associated with the reduction of NAD(P)+ into NAD(P)H. Due to this property, FDH is used as a crucial enzyme in the redox biosynthesis system for cofactor regeneration. Nevertheless, the application of natural FDH in industrial production is hampered by low catalytic efficiency, poor stability, and inefficient coenzyme utilization. This review summarized the structural characteristics and catalytic mechanism of FDH, as well as the advances in protein engineering of FDHs toward improved enzyme activity, catalytic efficiency, stability and coenzyme preference. The applications of using FDH as a coenzyme regeneration system for green biomanufacturing of chiral compounds were summarized.

Applications of nitrile converting enzymes in the production of fine chemicals / 生物工程学报

Nitriles are an important type of synthetic intermediates in the production of fine chemicals because of their easy preparations and versatile transformations. The traditional chemical conversion of nitriles to carboxylic acids and amides is feasible but it requires relatively harsh conditions of heat, acid or alkali. Nitrile converting enzymes (nitrilase, nitrile hydratase and amidase) which are used as biocatalyst for the production of fine chemicals have attracted substantial interest because of their ability to convert readily available nitriles into the corresponding higher value amides or acids under mild conditions with excellent chemo-, regio- and stereo-selectivities. Many nitrile converting enzymes have been explored and widely used for the production of fine chemicals. In this paper, various examples of biocatalytic synthesis of pharmaceuticals and their intermediates, agrochemicals and their intermediates, food and feed additives, and other fine chemicals are presented. In the near future, an increasing number of novel nitrile converting enzymes will be screened and their potential in the production of useful fine chemicals will be further exploited.

Cloning and expression of Lactobaceillus reuteri glycerol dehydratase gene in Escherichia coil / 生物工程学报

There is growing interest in biodiesel and this results in the accumulation of glycerol. The exploitation and application of glycerol has attracted more and more attention. In the current study, glycerol was biotransformed to produce 3-hydroxypropionaldehyde by genetic engineering bacteria. It is known that 3-hydroxypopionaldehyde has been widely used as an important intermediate for chemicals, effective antimicrobial agent, and fix agent for tissues. A pair of primers was designed on the basis of the sequence of both NH2-terminus and the amino acid sequence of glycerol dehydratase reported by NCBI, and a fragment about 1.6 kb was obtained by PCR amplification using the total genome DNA of Lactobacillus reuteri as template, then the fragment was cloned to the pMD18-T vector and sequenced. Two specific primers were designed according to the obtained sequence, and a fragment with length of 1674 bp was amplified using PCR with these two specific primers. Consequently, the resulting products were digested with EcoR I and Hind III and ligated using T4 DNA ligase to the pET28b vector digested with the same enzymes. The recombinant plasmid, named pET28b-dhaB, was transformed into E. coli BL21. The positive clones were induced with IPTG and the expression products were further analyzed by SDS-PAGE, indicating that protein with a molecule weight of around 65 kD was obtained. Furthermore, the glycerol dehydratase activity was evaluated and compared with the wild type strain as well.