Objective To design and express a novel peptide based on ricin toxin antibody in E. coli, and to evaluate its biological activity. Methods Based on the crystal structure of ricin toxin A chain (RTA) and the RTA-rRNA interact in the complex model, the steric conformation of RTA was theoretical modeled and its functional domain was preliminarily determined. The humanized single-domain RTA antibody was designed rationally by computer-guidod molecular design method. Its coding sequence was ob- tained by overlapping extension PCR, and cloned into the pET-32a vector. The fusion protein was then ex-pressed in E. coli BL21 (DE3), identified by Western blot, and purified with Ni-NTA agarose. The binding and neutralizing activity of this novel peptide for riein was evaluated by competitive ELlSA assay and MTT assay. Results A recombinant human single-domain antibody expressing a polypeptide against RTA in the CDR3 loop was designed. The fusion protein was successfully expressed in E. coll. The purified protein can bind to ricin, and neutralize its activity in SP2/0 viability assay. Conclusion The success of the novel pep-tide based on riein toxin antibody provides a novel method to develop new generation of ricin antagonists.

Objective To analyze serum amyloid protein A (SAA) subtype and amino acid mutation sequence of the renal biopsy specimens from patients with renal amyloidosis secondary to ankylosing spondylitis (AS) by laser microdissection combined with mass spectometry.Methods Kidney biopsy formalin-preserved paraffin-embedded (FFPE) specimen slices were stained by Congo red,the positive areas of Congo red staining were selected by microdissection,after trypsin hydrolysis and filtration,peptide samples were subjected to liquid chromatography tandem mass spectrometry.Analysis softwares were used to evaluate the results,and the patient's amino acid sequence of SAA protein was compared to mutant amino acid sequence reported by literature or deduced from mutant SAA gene to determine whether there was a variation.Results SAA1 and SAA2 proteins with high abundance were identified by mass spectrometry,serum amyloid P and apolipoprotein E were also detected.No variation of SAA1 and SAA2 protein was detected.Conclusions The SAA1 and SAA2 proteins in AA amyloidosis secondary to ASwere identified for the first time,which enriched the pathogenesis of amyloidosis secondary to AS and provided a new method for the accurate classification of AA amyloidosis.

Objective:To evaluate the diagnostic value of urine proteomics in interstitial lung disease.Methods:A case control study was conducted. 10 patients (age 56.70±14.78 years) with interstitial lung disease, 9 patients (age 51.30±23.26 years) with pulmonary infection and 10 healthy controls (age 50.20±6.07 years) from the physical examination center were selected from China-Japan Friendship Hospital from March 12 to April 15, 2023. The urine proteomics of three groups of people were studied using Liquid chromatography-mass spectrometry proteomics technology. Based on Data-Independent Acquisition mass spectrometry quantitative technology, three groups of people were compared, and t-test was performed between groups and relevant functional analysis was conducted.Results:A total of 2 730 proteins were identified. Three groups of people can be clearly distinguished by urine proteome using partial least squares discriminant analysis based on orthogonal signal correction. Quantitative comparison of proteins was conducted by the screening criteria for differential proteins with P<0.05 and protein abundance fold changes of>3/2 or<2/3. 49 proteins between interstitial lung disease patients and healthy people, as well as 57 proteins between interstitial lung disease patients and infectious diseases patients, were significantly changed. ECM receptor interaction and complement-coagulation cascade pathways were enriched by GO enrichment and KEGG analysis on differentially expressed proteins. Conclusions:Urinary proteomics can effectively distinguish patients with interstitial lung disease from those with pulmonary infections and the normal population. The differential proteins identified in this experiment have certain diagnostic performance (AUC value 0.68-1.00) and can be used as potential disease markers for the diagnosis of interstitial lung disease.

The Brodmann area(BA)-based map is one of the most widely used cortical maps for studies of human brain functions and in clinical practice;however,the molecular architecture of BAs remains unknown.The present study provided a global multiregional proteomic map of the human cerebral cortex by analyzing 29 BAs.These 29 BAs were grouped into 6 clusters based on similarities in proteomic patterns:the motor and sensory cluster,vision cluster,auditory and Broca's area cluster,Wernicke's area cluster,cingulate cortex cluster,and heterogeneous function cluster.We identified 474 cluster-specific and 134 BA-specific signature proteins whose functions are closely associated with specialized functions and disease vulnerability of the corresponding clus-ter or BA.The findings of the present study could provide explanations for the functional connec-tions between the anterior cingulate cortex and sensorimotor cortex and for anxiety-related function in the sensorimotor cortex.The brain transcriptome and proteome comparison indicates that they both could reflect the function of cerebral cortex,but show different characteristics.These pro-teomic data are publicly available at the Human Brain Proteome Atlas(www.brain-omics.com).Our results may enhance our understanding of the molecular basis of brain functions and provide an important resource to support human brain research.