Physicochemical, enzymatic and molecular characterisation of the storage protein of aerial tuber, Dioscorea bulbifera Linn.

Olukemi Adetutu Osukoya,Adenike Kuku

doi:10.1186/s43141-020-00040-y

Abstract

BackgroundThe storage protein of the aerial tuber of Dioscorea bulbifera was purified and its physicochemical, enzymatic and molecular properties determined with a view to comparing its functionality and genetic relatedness with other storage proteins. ResultsThe purified protein had molecular weight of 21 kDa. The protein showed carbonic anhydrase, trypsin inhibitory, dehydroascorbate reductase and monodehydroascorbate reductase activities. Amplifications with polymerase chain reactions resulted in the detection of two genes encoding the storage protein. The deduced amino acid sequence of the shorter and larger genes had homologies with the storage proteins of members of the Dioscorea family. ConclusionThe study concluded that the storage protein of the aerial tuber of D. bulbifera had similar properties with those of other Dioscorea species and may be suitable for development as functional food.

Highlights

Yam, a dioecious plant belonging to the Dioscorea genus, is an important staple crop in many areas of the tropics and sub-tropics [1]
Purification of storage protein The crude extract of the aerial tuber of Dioscorea bulbifera (379.60 mg) when subjected to 70% ammonium sulphate precipitation gave 130.80 mg protein which corresponds to 34.46% yield
The crude extracts of fresh aerial tuber of D. bulbifera prepared at 25 °C and at pH 8.3 showed optimum protein concentration, which is similar to the results obtained from previous reports [23, 24] on the effect of heating temperature and pH on the major storage protein of various yam species

Summary

Introduction

A dioecious plant belonging to the Dioscorea genus, is an important staple crop in many areas of the tropics and sub-tropics [1]. The major role of storage proteins is to act as stores of nitrogen, sulphur and carbon, which are accumulated in both vegetative and reproductive tissues They serve as a reservoir for later stages of plant development [9, 10]. Storage proteins provide nutrients to support the growth of new plants as seedlings (from seeds) or shoots (from tubers) They are localized in specific organs, cell types and subcellular compartments in discrete deposits (protein bodies) where they facilitate high-level accumulation without any adverse effects on other cellular functions. They allow plants to survive periods of adverse conditions between growing season [11]. The storage protein of the aerial tuber of Dioscorea bulbifera was purified and its physicochemical, enzymatic and molecular properties determined with a view to comparing its functionality and genetic relatedness with other storage proteins

Methods

Results

Discussion

Conclusion