The Proteins of Plant Defensin Family and their Application Beyond Plant Disease Control

Abstract

Plant defensins are a family of small, cysteine-rich and basic proteins. Proteins of the family constitute the major innate immune system of plants and insects. The most significant feature of the family is the conserved cysteine scaffold and one alpha-helix and a triple strand anti parallel beta-sheet connected by the scaffold. Proteins of the family display anti-microbial and anti-fungal activities and a broad spectrum of biological functions. The proteins also demonstrate ultra stable proprieties even in extreme environments. In the past twenty years, patents on the proteins and their applications have increased as technologies have been developed. By utilizing protein engineering approach, medical applications of proteins of the family have been developed. By reviewing patents on proteins of the family, the application development trend of the protein family is traced. Currently, the development of proteins of the family is still in the initial and discovery stage. For their excellent physical and chemical proprieties, it is believed that application of the proteins in the biomedical area should have a high potential and the future of proteins of the plant defensin family.

Development and Engineering of CSαβ Motif for Biomedical Application

“…It has been reported that proteins with a CSαβ motif equip ultra stabilities to several extreme environments such as urea at a concentration of 6M, a temperature over than 95°C, and resist protease digestion without changing its structure (Malavasic et al, 1996;Yang et al, 2009). In Table 1, the properties of CSαβ motif and singledomain antibody are listed and compared (Holt et al, 2003;Skerra, 2007;Yang et al, 2009;Yang & Lyu, 2008). For their advantages, such as high specificity and affinity, antibodies still are the most popular protein scaffold for engineering.…”

“…Their functions are highly varied and sturctures are ultra-stable. There is a possibility to utilize CSαβ motif as an engineering scaffold for biomedical applications (Yang & Lyu, 2008 …”

“…Berry fruits of Pentadiplandra brazzeana have sweetness and are traditional foods of African natives Yang & Lyu, 2008). For a long time, the sweetness of the berry fruits is a secret.…”

A Review: Biological and Technological Functions of Barley Seed Pathogenesis-Related Proteins (PRs)

“…The transgenic expression of defensins in plants has been reviewed recently 328 as well as defensins biotechnological use in agriculture and pharmacy 229,265,362 . Defensins inhibit human fungal pathogens, including Candida and Aspergillus spp., and are employed as novel leads in antifungal therapeutics 335,341 .…”

“…Defensins inhibit human fungal pathogens, including Candida and Aspergillus spp., and are employed as novel leads in antifungal therapeutics 335,341 . The excellent physical and chemical properties of defensins enable their usage in the biomedicinal area as defensins are stable even in extreme environments 362 . The presence of barley defensins in beer is not yet established.…”