Structure, physicochemical properties, and biological activities of protein hydrolysates from Zanthoxylum seed.

BACKGROUND: Zanthoxylum seed, as a low-cost and easily accessible plant protein resource, has good potential in the food industry. But protein and its hydrolysates from Zanthoxylum seed are underutilized due to the dearth of studies on them. This study aimed to investigate the structure and physicochemical and biological activities of Zanthoxylum seed protein (ZSP) hydrolysates prepared using Protamex®, Alcalase®, Neutrase®, trypsin, or pepsin. RESULTS: Hydrolysis using each of the five enzymes diminished average particle size and molecular weight of ZSP but increased random coil content. ZSP hydrolysate prepared using pepsin had the highest degree of hydrolysis (24.07%) and the smallest molecular weight (<13 kDa) and average particle size (129.80 nm) with the highest solubility (98.9%). In contrast, ZSP hydrolysate prepared using Alcalase had the highest surface hydrophobicity and foaming capacity (88.89%), as well as the lowest foam stability (45.00%). Moreover, ZSP hydrolysate prepared using Alcalase exhibited the best hydroxyl-radical scavenging (half maximal inhibitory concentration (IC50 ) 1.94 mg mL-1 ) and ferrous-ion chelating (IC50 0.61 mg mL-1 ) activities. Additionally, ZSP hydrolysate prepared using pepsin displayed the highest angiotensin-converting enzyme inhibition activity (IC50 0.54 mg mL-1 ). CONCLUSION: These data showed that enzyme hydrolysis improved the physicochemical properties of ZSP, and enzymatic hydrolysates of ZSP exhibited significant biological activity. These results provided validation for application of ZSP enzymatic hydrolysates as antioxidants and antihypertensive agents in the food or medicinal industries. © 2023 Society of Chemical Industry.

A head transcriptome provides insights into odorant binding proteins of the bamboo grasshopper.

The bamboo grasshopper Ceracris kiangsu is a famous bamboo pest in China. The identification of genes involved in olfactory behavior of C. kiangsu is necessary for better understanding the molecular basis and expression profiles of behavior ecology. However, necessary genomic and transcriptomic data are lacking in the species, limiting control efficiency. The primary objective of this study was to find and describe odorant binding proteins in the head of the bamboo grasshopper. We performed the paired-end sequencing on an Illumina Hiseq2000 following the vendor's recommended protocol. Functional annotation was performed by comparison with public databases. OBP genes were first identified using BLASTN and BLASTX results from our C. kiangsu datebase, which was established from the date of transcriptome sequencing. The gene-specific primers were used to conduct RT-PCR to detect the tissue distribution of OBPs using a SYBR Premix ExTaq kit following the manufacturer's instructions with a real-time thermal cycler. We obtained more than 133 million clean reads derived from the C. Kiangsu heads using the next-generation sequencing, which were assembled into 260,822 unique sequences (average 814 bp). We have detected eight putative odorant binding protein genes (OBPs) of C. kiangsu for the first time, and analyzed the expression profiles of the OBPs in different tissues (head, antenna, mouthpart, body and leg). Our results reveal that the eight OBPs display a clear divergence, strongly indicating that they possessed diverse functions, and thus provides comprehensive sequence analysis for elucidating the molecular basis of OBPs in C. kiangsu. In addition, we find that the relative expression levels of OBP1, OBP2 and OBP8 are significantly higher in the antennae as compared to the other OBP genes, suggesting that these three OBP genes play crucial roles in the locust's odorant discrimination. In general, this is the first study to characterize the complete head transcriptome of C. kiangsu using high-throughput sequencing. The study opens a window for functional characterization of the OBPs of C. kiangsu, with potential for new or refined applications of semiochemicals for control of this notorious pest.

Characterization of the complete mitochondrial genome of tea tussock moth, Euproctis pseudoconspersa (Lepidoptera: Lymantriidae) and its phylogenetic implications.

In present work, we described the mitochondrial genome (mitogenome) of the tea tussock moth Euproctis pseudoconspersa (Lepidoptera: Lymantriidae). The complete mitogenome of E. pseudoconspersa is a circular genome 15,461 bp in size. It contains 37 genes and an A+T-rich region usually presented in lepidopteran mitogenomes, which genes share a lot of features with other known lepidopteran mitogenomes. Nucleotide composition of A+T in this mitogenome is 79.92%, and the AT skew is slightly positive. Both codon distribution and relative synonymous codon usage of the 13 protein-coding genes (PCGs) are consistent with those published lepidopteran sequences. All tRNA genes have typical cloverleaf secondary structures, except for the tRNA(Ser(AGN)), in which the dihydrouridine (DHU) arm is simplified down to a loop. The A+T-rich region of E. pseudoconspersa mitogenome possess the motif 'ATAGA' and poly-T stretch as the formerly identified conserved elements of Lepidoptera mitogenomes. The phylogenetic relationships were reconstructed by using maximum likelihood (ML) and Bayesian inference (BI) methods based on nucleotide sequences of 13 PCGs of 38 moths. The results were very consistent with the traditional relationships within Noctuoidea from morphological data, and showed that Lymantriidae is more closely related to Erebidae than to Noctuidae.