Horseradish and soybean peroxidases (HRP and SBP, respectively) are useful 9 biotechnological tools. HRP is often termed the classical plant heme peroxidase, and 10 although it has been studied for decades our understanding has deepened since its 11 cloning and subsequent expression, which has enabled numerous mutational and 12 protein engineering studies. SBP, however, has been neglected until recently; despite 13 offering a real alternative to HRP that actually outperforms it in terms of stability. 14 SBP is now used in numerous biotechnological applications, including biosensors. 15Review of both is timely. This article summarises and discusses the main insights into 16 the structure and mechanism of HRP, with special emphasis on HRP mutagenesis, and 17 outlines its use in a variety of applications. It also reviews current knowledge and 18 applications to date of SBP, particularly biosensors. The final paragraphs speculate on 19 the future of plant heme-based peroxidases, with probable trends outlined and 20 explored. 21 22

Abstract

Objective: This review examines on our current understanding of microbial lipase solvent tolerance, with a specific focus on the molecular strategies employed to improve lipase stability in a non-aqueous environment. Results: It provides an overview of known solvent tolerant lipases and of approaches to improving solvent stability such as; enhancing stabilising interactions, modification of residue flexibility and surface charge alteration. It shows that judicious selection of lipase source supplemented by appropriate enzyme stabilisation, can lead to a wide application spectrum for lipases. Conclusion: Organic solvent stable lipases are, and will continue to be, versatile and adaptable biocatalytic workhorses commonly employed for industrial applications in the food, pharmaceutical and green manufacturing industries.

Methylxanthines are among the most widely consumed drugs in the world and evidence of their health benefits has been growing in recent years. Primary Amine Oxidase (PrAO) has been recognized as a therapeutic target for the amelioration of inflammatory, vascular, and neurodegenerative diseases. Previous work in our laboratories showed that caffeine inhibited Bovine PrAO with a Ki of 1.0 mM using benzylamine as substrate. This study aimed to extend our previous work and explore the possibility that related methylxanthines might influence PrAO activity. While paraxanthine, theophylline, and 7‐methylxanthine had little effect on PrAO, theobromine was a noncompetitive inhibitor with a Ki of 276 ± 44 µM. The specific structural elements of methylxanthines that are required for inhibition allow us to suggest that their binding site on PrAO may be a target for therapeutics. The health benefits associated with dietary methylxanthine consumption could involve PrAO inhibition. Practical applications Inhibition of PrAO by methylxanthines may be significant in conferring health benefits. The design of PrAO inhibitors based on the structural motifs identified in this study (N‐methylation at specific locations) is indicated. Existing therapeutics based on a core xanthine structure can be evaluated for their effects on PrAO. PrAO inhibition must be considered as a potential mediator of the beneficial health effects of some methylxanthines. If inhibition in human tissues is comparable to, or greater than, that found in these studies it points to an important role for these compounds in human health.

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