Laboratoire de Chimie Générale, Faculté de Pharmacie, Université Libre de Bruxelles, Campus Plaine, boulevard du Triomphe, Brussels, Belgium.
Plant Sci. 2011 Oct;181(4):347-54. doi: 10.1016/j.plantsci.2011.06.009. Epub 2011 Jun 23.
Human perception of sweetness, behind the felt pleasure, is thought to play a role as an indicator of energy density of foods. For humans, only a small number of plant proteins taste sweet. As non-caloric sweeteners, these plant proteins have attracted attention as candidates for the control of obesity, oral health and diabetic management. Significant advances have been made in the characterization of the sweet-tasting plant proteins, as well as their binding interactions with the appropriate receptors. The elucidation of sweet-taste receptor gene sequences represents an important step towards the understanding of sweet taste perception. However, many questions on the molecular basis of sweet-taste elicitation by plant proteins remain unanswered. In particular, why homologues of these proteins do not elicit similar responses? This question is discussed in this report, on the basis of available sequences and structures of sweet-tasting proteins, as well as of sweetness-sensing receptors. A simple procedure based on sequence comparisons between sweet-tasting protein and its homologous counterparts was proposed to identify critical residues for sweetness elicitation. The open question on the physiological function of sweet-tasting plant proteins is also considered. In particular, this review leads us to suggest that sweet-tasting proteins may interact with taste receptor in a serendipity manner.
人类对甜味的感知，除了感受到的愉悦之外，还被认为是食物能量密度的指标。对于人类来说，只有少数植物蛋白具有甜味。作为无热量的甜味剂，这些植物蛋白作为肥胖、口腔健康和糖尿病管理控制的候选物引起了人们的关注。在鉴定具有甜味的植物蛋白及其与相应受体的结合相互作用方面取得了重大进展。阐明甜味受体基因序列是理解甜味感知的重要一步。然而，关于植物蛋白引发甜味的分子基础仍有许多问题尚未得到解答。特别是，为什么这些蛋白质的同源物不会引起类似的反应？本报告根据现有甜味蛋白的序列和结构以及甜味感知受体，讨论了这一问题。提出了一种基于甜味蛋白与其同源物序列比较的简单方法，以鉴定引发甜味的关键残基。同时还考虑了甜味植物蛋白的生理功能这一悬而未决的问题。特别是，本综述使我们提出，甜味蛋白可能以偶然的方式与味觉受体相互作用。
