Metal binding feature of copper‒induced metallothionein from freshwater crab Sinopotamon henanense reveals its Cu‒thionein character.

Sinopotamon Henanense expresses two metal‒induced metallothioneins (MTs), Cd‒induced MT and Cu‒induced MT (ShCuMT). The Cd‒induced MT has been characterized as a Cd‒thiolate MT. However, it is unknown whether ShCuMT is a Cu‒thiolate MT. In the present study, ShCuMT was expressed heterologously in Escherichia coli and purified by Ni‒NTA column and superdex‒75 column. And its metal‒binding feature was evaluated by DTNB reaction, circular dichroism spectroscopy (CD), isothermal microtitration (ITC), electrospray flight mass spectrometry (ESI‒TOF‒MS), and matrix‒assisted laser desorption ionization flight mass spectrometry (MALDI‒TOF‒MS). Bioinformatics analysis demonstrated that ShCuMT possessed the cysteine‒triplet motif of a Cu‒specific MT. Expression and purification of ShCuMT illustrated that SUMO tag used as the production system for ShCuMT resulted in a high production yield. The stability order of ShCuMT binding metal ions were Cu (Ⅰ) > Cd (Ⅱ) > Zn (Ⅱ). The CD spectrum indicated that ShCuMT binding with Cu (I) exhibited a compact thiol metal clusters structure. Besides, there emerged no a visible nickel‒thiol absorption after Ni‒NTA column affinity chromatography. The ITC results implied that Cu‒ShCuMT possessed the optimal thermodynamic conformation and the highest stoichiometric number of Cu (Ⅰ). Overall, the results suggested that SUMO fusion system is a robust and inexpensive approach for ShCuMT expression and Ni‒NTA column had no influence on metal binding of ShCuMT and Cu(Ⅰ) was considered its cognate metal ion, and ShCuMT possessed canonical Cu‒thiolate characteristics. The metal binding feature of ShCuMT reported here contributes to elucidating the structure‒function relationship of ShCuMT in S. Henanense.

Investigation on the contribution of swim bladder to hearing in crucian carp (Carassius carassius).

The swim bladder in some teleost fish functions to transfer the sound energy of acoustic stimuli to the inner ears. This study uses the auditory evoked potential tests, micro-computed tomography scanning, reconstruction, and numerical modeling to assess the contribution of the swim bladder to hearing in crucian carp (Carassius carassius). The auditory evoked potential results show that, at the tested frequency range, the audiogram of fish with an intact swim bladder linearly increases, ranging from 100 to 600 Hz. Over this frequency, the sound pressure thresholds have a local lowest value at 800 Hz. The mean auditory threshold of fish with an intact swim bladder is lower than that of fish with a deflated swim bladder by 0.8-20.7 dB. Furthermore, numerical simulations show that the received pressure of the intact swim bladders occurs at a mean peak frequency of 826 ± 13.6 Hz, and no peak response is found in the deflated swim bladders. The increased sensitivity of reception in sound pressure and acceleration are 34.4 dB re 1 µPa and 40.3 dB re 1 m·s-2 at the natural frequency of swim bladder, respectively. Both electrophysiological measurement and numerical simulation results show that the swim bladder can potentially extend hearing bandwidth and further enhance auditory sensitivity in C. carassius.

[Characteristics of Epiphytic Bacterial Community on Submerged Macrophytes in Water Environment Supplemented with Reclaimed Water].

Biofilms attached to submerged macrophytes play an important role in improving the water quality of the water environment supplemented with reclaimed water. In order to explore the effects of reclaimed water quality and submerged macrophyte species on the characteristics of an epiphytic bacterial community, different types of submerged macrophytes were selected as research objects in this study. 16S rRNA high-throughput sequencing technology was used on the epiphytic bacteria and the surrounding environmental samples to analyze the bacterial community structure and functional genes. The results showed that approximately 20%-35% of the nitrogen and phosphorus nutrients were absorbed and utilized in the water environment supplemented with reclaimed water. However, the COD, turbidity, and chroma of the downstream water were significantly increased. The bacterial community of the biofilms attached to submerged macrophytes was significantly different from that in the surrounding environment (soil, sediment, and water body) and in the activated sludge that was treated by reclaimed water. In terms of bacterial community diversity, the richness and diversity were significantly lower than those of soil and sediment but higher than those of plankton bacteria in water. In terms of bacterial community composition, dominant genera and corresponding abundances were also different from those of other samples. The main dominant bacterial genera were Sphingomonas, Aeromonas, Pseudomonas, and Acinetobacter, accounting for 7%-40%, respectively. Both macrophyte species and the quality of reclaimed water (BOD5, TN, NH4+-N, and TP) could affect the bacterial community. However, the effect of water quality of the bacterial community was greater than that of macrophytes species. Additionally, the quality of reclaimed water also affected the abundance of functional genes in the bacterial community, and the relative abundance of nitrogen and phosphorus cycling functional genes was higher in areas with higher nitrogen and phosphorus concentrations.

Baicalin ameliorates the gut barrier function and intestinal microbiota of broiler chickens.

The deoxynivalenol (DON)-contaminated feeds can impair chicken gut barrier function, disturb the balance of the intestinal microbiota, decrease chicken growth performance and cause major economic loss. With the aim of investigating the ameliorating effects of baicalin on broiler intestinal barrier damage and gut microbiota dysbiosis induced by DON, a total of 150 Arbor Acres broilers are used in the present study. The morphological damage to the duodenum, jejunum, and ileum caused by DON is reversed by treatment with different doses of baicalin, and the expression of tight junction proteins (ZO-1, claudin-1, and occludin) is also significantly increased in the baicalin-treated groups. Moreover, the disturbance of the intestinal microbiota caused by DON-contaminated feed is altered by baicalin treatment. In particular, compared with those in the DON group, the relative abundances of Lactobacillus, Lachnoclostridium, Ruminiclostridium and other beneficial microbes in the baicalin-treated groups are significantly greater. However, the percentage of unclassified_f__Lachnospiraceae in the baicalin-treated groups is significantly decreased in the DON group. Overall, the current results demonstrate that different doses of baicalin can improve broiler intestinal barrier function and the ameliorating effects on broiler intestinal barrier damage may be related to modulations of the intestinal microbiota.

Dietary supplementation of osthole and icariin improves the production performance of laying hens by promoting follicular development.

Osthole (Ost) and icariin (Ica) are extracted from traditional Chinese medicine Cnidium monnieri and Epimedii Folium, respectively, and both exhibit estrogen-like biological activity. This study aimed to determine the efficacy and safety of combining Ost with Ica on the production performance of laying hens and to explore their possible mechanisms. The production performance, egg quality, residues of Ost and Ica in eggs, serum reproductive hormone levels, expression of ovarian reproductive hormone receptor, proliferation of granulosa cells in small yellow follicles (SYF), and progesterone secretion in large yellow follicles (LYF) related genes and proteins expression were detected. The results showed that adding 2 mg/kg Ost + 2 mg/kg Ica to the feed increased the laying rate, average egg weight, Haugh unit, and protein height of laying hens. Serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), and progesterone (P4) levels increased, and the expression of ovarian estrogen receptor (ER), follicle-stimulating hormone receptor (FSHR), and progesterone receptor (PGR) mRNA was up-regulated. Additionally, the mRNA and protein levels of steroidogenesis acute regulatory protein (StAR), cytochrome P450 side-chain cleavage (P450scc), and 3ß-hydroxysteroid dehydrogenase (3ß-HSD) increased in LYF. Furthermore, mRNA and protein levels of proliferating cell nuclear antigen (PCNA), cyclin E1, and cyclin A2 were up-regulated in SYF. The residues of Ost and Ica in egg samples were not detected by high-performance liquid chromatography (HPLC). In conclusion, dietary supplementation of Ost and Ica increased granulosa cells proliferation in SYF and increased P4 secretion in granulosa cells of LYF, ultimately improving the production performance of laying hens.

Characterization and function analysis of cathepsin C in Marsupenaeusjaponicus.

Cathepsin C is a cysteine protease widely found in invertebrates and vertebrates, and has the important physiological role participating in proteolysis in vivo and activating various functional proteases in immune/inflammatory cells in the animals. In order to study the role of cathepsin C in the disease resistance of shrimp, we cloned cathepsin C gene (MjcathC) from Marsupenaeus japonicus, analyzed its expression patterns in various tissues, performed MjcathC-knockdown, and finally challenged experimental shrimps with Vibrio alginolyticus and WSSV. The results have shown the full length of MjcathC is 1782 bp, containing an open reading frame of 1350 bp encoding 449 amino acids. Homology analysis revealed that the predicted amino acid sequence of MjcathC shared respectively 88.42 %, 87.36 % and 87.58 % similarity with Penaeus monodon, Fenneropenaeus penicillatus and Litopenaeus vannamei. The expression levels of MjcathC in various tissues of healthy M. japonicus are the highest in the liver, followed by the gills and heart, and the lowest in the stomach. The expression levels of MjcathC were significantly up-regulated in all examined tissues of shrimp challenged with WSSV or V. alginolyticus. After knockdown-MjcathC using RNAi technology in M. japonicus, the expression levels of lectin and heat shock protein 70 in MjcathC-knockdown shrimp were significantly down-regulated, and the mortality of MjcathC-knockdown shrimp challenged by WSSV and V. alginolyticus significantly increased. Knockdown of the MjcathC reduced the resistance of M. japonicus to WSSV and V. alginolyticus. The above results have indicated that cathepsin C may play an important role in the antibacterial and antiviral innate immunity of M. japonicus.

Rapid, antibiotic incubation-free determination of tuberculosis drug resistance using machine learning and Raman spectroscopy.

Tuberculosis (TB) is the world's deadliest infectious disease, with over 1.5 million deaths annually and 10 million new cases reported each year. The causative organism, Mycobacterium tuberculosis (Mtb) can take nearly 40 days to culture, a required step to determine the pathogen's antibiotic susceptibility. Both rapid identification of Mtb and rapid antibiotic susceptibility testing (AST) are essential for effective patient treatment and combating antimicrobial resistance. Here, we demonstrate a rapid, culture-free, and antibiotic incubation-free drug susceptibility test for TB using Raman spectroscopy and machine learning. We collect few-to-single-cell Raman spectra from over 25,000 cells of the MtB complex strain Bacillus Calmette Guerin (BCG) resistant to one of the four mainstay anti-TB drugs, isoniazid, rifampicin, moxifloxacin and amikacin, as well as a pan susceptible wildtype strain. By training a neural network on this data, we classify the antibiotic resistance profile of each strain, both on dried samples and in patient sputum samples. On dried samples, we achieve >98% resistant versus susceptible classification accuracy across all 5 BCG strains. In patient sputum samples, we achieve ~79% average classification accuracy. We develop a feature recognition algorithm in order to verify that our machine learning model is using biologically relevant spectral features to assess the resistance profiles of our mycobacterial strains. Finally, we demonstrate how this approach can be deployed in resource-limited settings by developing a low-cost, portable Raman microscope that costs <$5000. We show how this instrument and our machine learning model enables combined microscopy and spectroscopy for accurate few-to-single-cell drug susceptibility testing of BCG.

Scutellarin targets Wnt5a against zearalenone-induced apoptosis in mouse granulosa cells in vitro and in vivo.

Zearalenone (ZEA) poses severe reproductive toxicity to both humans and animals. Scutellarin has been demonstrated to rescue ZEA-induced apoptosis in mouse ovarian granulosa cells (GCs), but its specific targets remain unclear. In the present study, the potential targets of scutellarin were determined to clarify the mechanisms of scutellarin against ZEA-induced ovarian damage. 287 targets of scutellarin in mouse ovarian GCs were obtained by magnetic nano-probe-based fishing assay and liquid chromatography-tandem mass spectrometry. Wnt5a had the lowest binding free energy with scutellarin at - 8.3 kcal/mol. QRT-PCR and western blot showed that scutellarin significantly increased the Wnt5a and ß-catenin expression compared with the ZEA-treated group, and cleaved-caspase-3 expression was significantly increased in the scutellarin-treated group after interfering with the expression of Wnt5a. The affinity constant (KD) of Wnt5a and scutellarin was 1.7 × 10-5 M. The pull-down assay also demonstrated that scutellarin could specifically bind to Wnt5a protein. Molecular docking results showed that scutellarin could form hydrogen bonds with TRY52, GLN56, and SER90 on Wnt5a protein, and western blot assay confirmed SER90 was an important site for the binding. Scutellarin significantly increased Wnt5a and ß-catenin expression and decreased cleaved-caspase-3 expression in ovarian tissues of mice. In conclusion, scutellarin exerted anti-apoptotic effects on ZEA-induced mouse ovarian GCs by targeting Wnt5a.

Matrine Targets Intestinal Lactobacillus acidophilus to Inhibit Porcine Circovirus Type 2 Infection in Mice.

Porcine circovirus type 2 (PCV2) has caused huge economic losses to the pig industry across the world. Matrine is a natural compound that has been shown to regulate intestinal flora and has anti-PCV2 activity in mouse models. PCV2 infection can lead to changes in intestinal flora. The intestinal flora has proved to be one of the important pharmacological targets of the active components of Traditional Chinese Medicine. This study aimed to determine whether matrine exerts anti-PCV2 effects by regulating intestinal flora. In this study, fecal microbiota transplantation (FMT) was used to evaluate the effect of matrine on the intestinal flora of PCV2-infected Kunming (KM) mice. The expression of the Cap gene in the liver and the ileum, the relative expression of IL-1ß mRNA, and the Lactobacillus acidophilus (L. acidophilus) gene in the ileum of mice were determined by real-time quantitative polymerase chain reaction (qPCR). ELISA was used to analyze the content of secretory immunoglobulin A (SIgA) in small intestinal fluid. L. acidophilus was isolated and identified from the feces of KM mice in order to study its anti-PCV2 effect in vivo. The expression of the Cap gene in the liver and the ileum and the relative expression of L. acidophilus and IL-1ß mRNA in the ileum were determined by qPCR. The results showed that matrine could reduce the relative expression of IL-1ß mRNA by regulating intestinal flora, and that its pharmacological anti-PCV2 and effect may be related to L. acidophilus. L. acidophilus was successfully isolated and identified from the feces of KM mice. The in vivo experiment revealed that administration of L. acidophilus also reduced the relative expression of IL-1ß mRNA, and that it had anti-PCV2 effects in PCV2-infected mice. It was found that matrine could regulate the abundance of L. acidophilus in the gut of mice to exert an anti-PCV2 effect and inhibit PCV2-induced inflammatory response.

Aldolase A Accelerates Cancer Progression by Modulating mRNA Translation and Protein Biosynthesis via Noncanonical Mechanisms.

Aldolase A (ALDOA), a crucial glycolytic enzyme, is often aberrantly expressed in various types of cancer. Although ALDOA has been reported to play additional roles beyond its conventional enzymatic role, its nonmetabolic function and underlying mechanism in cancer progression remain elusive. Here, it is shown that ALDOA promotes liver cancer growth and metastasis by accelerating mRNA translation independent of its catalytic activity. Mechanistically, ALDOA interacted with insulin- like growth factor 2 mRNA-binding protein 1 (IGF2BP1) to facilitate its binding to m6 A-modified eIF4G mRNA, thereby increasing eIF4G protein levels and subsequently enhancing overall protein biosynthesis in cells. Importantly, administration of GalNAc-conjugated siRNA targeting ALDOA effectively slows the tumor growth of orthotopic xenografts. Collectively, these findings uncover a previously unappreciated nonmetabolic function of ALDOA in modulating mRNA translation and highlight the potential of specifically targeting ALDOA as a prospective therapeutic strategy in liver cancer.

Culture-Independent Multiplexed Detection of Drug-Resistant Bacteria Using Surface-Enhanced Raman Scattering.

The rapid and accurate detection of bacteria resistance to ß-lactam antibiotics is critical to inform optimal treatment and prevent overprescription of potent antibiotics. Here, we present a fast, culture-independent method for the detection of extended-spectrum ß-lactamases (ESBLs) using surface-enhanced Raman scattering (SERS). The method uses Raman probes that release sulfur-based Raman active molecules in the presence of ß-lactamases. The released thiol molecules can be captured by gold nanoparticles, leading to amplified Raman signals. A broad-spectrum cephalosporin probe R1G and an ESBL-specific probe R3G are designed to enable duplex detection of bacteria expressing broad-spectrum ß-lactamases or ESBLs with a detection limit of 103 cfu/mL in 1 h incubation. Combined with a portable Raman microscope, our culturing-free SERS assay has reduced screening time to 1.5 h without compromising sensitivity and specificity.

Target Discovery of Matrine against PRRSV in Marc-145 Cells via Activity-Based Protein Profiling.

Porcine reproductive and respiratory syndrome (PRRS) seriously endangers the sustainable development of the pig industry. Our previous studies have shown that matrine can resist porcine reproductive and respiratory syndrome virus (PRRSV) infection. This study aimed to explore the anti-PRRSV targets of matrine in Marc-145 cells. Biotin-labeled matrine 1 and 2 were used as probes. MTT assay was used to determine the maximum non-cytotoxic concentration (MNTC) of each probe in Marc-145 cells. The anti-PRRSV activity of each probe was evaluated via MTT, qPCR and Western blot, and its anti-inflammatory activity was evaluated via qPCR and Western blot. The targets of matrine in Marc-145 cells were searched using activity-based protein profiling (ABPP), and compared with the targets predicted via network pharmacology for screening the potential targets of matrine against PRRSV. The protein-protein interaction networks (PPI) of potential targets were constructed using a network database and GO/KEGG enrichment analysis was performed. ACAT1, ALB, HMOX1, HSPA8, HSP90AB1, PARP1 and STAT1 were identified as potential targets of matrine, and their functions were related to antiviral capacity and immunity. Matrine may play an anti-PRRSV role by directly acting on ACAT1, ALB, HMOX1, HSPA8, HSP90AB1, PARP1 and STAT1.

Call properties of the large yellow croaker (Larimichthys crocea) during reproduction with insight into directivity.

The investigation of the large yellow croaker (Larimichthys crocea) deserves more attention due to its high commercial value as an important aquaculture fish species. This study was initiated by deploying a passive acoustic monitoring device to record the calls from the L. crocea during the spawning process in an aquaculture facility. The subsequent analysis suggested the croakers produced at least two types of calls with considerable energy distributed up to 1000 Hz. The acoustic data and the computed tomography scanning of an adult croaker were used to develop a numerical model to address the directivity of the calls at frequencies up to 1000 Hz. The radiation patterns at all frequencies were assigned with respective weights and then combined to estimate an overall acoustic radiation pattern for both types of the calls. The backward transmission was greater for both types of calls by 1.85 dB on average. The reduction of size by 20% in the swim bladder resulted in a stronger sidelobe in the frontal direction, indicating its influence on call directivity. These results provided information on the directivity of the croaker calls and understanding of fish acoustics.

Genome-wide identification and expression analysis of MYB gene family in Cajanus cajan and CcMYB107 improves plant drought tolerance.

MYB transcription factor (TF) is one of the largest superfamilies that play a vital role in multiple plant biological processes. However, the MYB family has not been comprehensively identified and functionally verified in Cajanus cajan, which is the sixth most important legume crop. Here, 170 CcR2R3-MYBs were identified and divided into 43 functional subgroups. Segmental and tandem duplications and alternative splicing events were found and promoted the expansion of the CcR2R3-MYB gene family. Functional prediction results showed that CcR2R3-MYBs were mainly involved in secondary metabolism, cell fate and identity, developmental processes, and responses to abiotic stress. Cis-acting element analysis of promoters revealed that stress response elements were widespread in the above four functional branches, further suggesting CcR2R3-MYBs were extensively involved in abiotic stress response. The transcriptome data and qRT-PCR results indicated that most of the CcR2R3-MYB genes responded to various stresses, of which the expression of CcMYB107 was significantly induced by drought stress. Overexpression of CcMYB107 enhanced antioxidant enzyme activity and increased proline and lignin accumulation, thus improving the drought resistance of C. cajan. Furthermore, Overexpression of CcMYB107 up-regulated the expression of stress-related genes and lignin biosynthesis genes after drought stress. Our findings established a strong foundation for the investigation of biological function of CcR2R3-MYB TFs in C. cajan.

MultiSero: An Open-Source Multiplex-ELISA Platform for Measuring Antibody Responses to Infection.

A multiplexed enzyme-linked immunosorbent assay (ELISA) that simultaneously measures antibody binding to multiple antigens can extend the impact of serosurveillance studies, particularly if the assay approaches the simplicity, robustness, and accuracy of a conventional single-antigen ELISA. Here, we report on the development of multiSero, an open-source multiplex ELISA platform for measuring antibody responses to viral infection. Our assay consists of three parts: (1) an ELISA against an array of proteins in a 96-well format; (2) automated imaging of each well of the ELISA array using an open-source plate reader; and (3) automated measurement of optical densities for each protein within the array using an open-source analysis pipeline. We validated the platform by comparing antibody binding to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) antigens in 217 human sera samples, showing high sensitivity (0.978), specificity (0.977), positive predictive value (0.978), and negative predictive value (0.977) for classifying seropositivity, a high correlation of multiSero determined antibody titers with commercially available SARS-CoV-2 antibody tests, and antigen-specific changes in antibody titer dynamics upon vaccination. The open-source format and accessibility of our multiSero platform can contribute to the adoption of multiplexed ELISA arrays for serosurveillance studies, for SARS-CoV-2 and other pathogens of significance.

Lightweight aerial image object detection algorithm based on improved YOLOv5s.

YOLOv5 is one of the most popular object detection algorithms, which is divided into multiple series according to the control of network depth and width. To realize the deployment of mobile devices or embedded devices, the paper proposes a lightweight aerial image object detection algorithm (LAI-YOLOv5s) based on the improvement of YOLOv5s with a relatively small amount of calculation and parameter and relatively fast reasoning speed. Firstly, to better detect small objects, the paper replaces the minimum detection head with the maximum detection head and proposes a new feature fusion method, DFM-CPFN(Deep Feature Map Cross Path Fusion Network), to enrich the semantic information of deep features. Secondly, the paper designs a new module based on VoVNet to improve the feature extraction ability of the backbone network. Finally, based on the idea of ShuffleNetV2, the paper makes the network more lightweight without affecting detection accuracy. Based on the VisDrone2019 dataset, the detection accuracy of LAI-YOLOv5s on the mAP@0.5 index is 8.3% higher than that of the original algorithm. Compared with other series of YOLOv5 and YOLOv3 algorithms, LAI-YOLOv5s has the advantages of low computational cost and high detection accuracy.

Transcriptomics integrated with metabolomics provides a new strategy for mining key genes in response to low temperature stress in Helictotrichon virescens.

H. virescens is a perennial herbaceous plant with highly tolerant to cold weather, but the key genes that respond to low temperature stress still remain unclear. Hence, RNA-seq was performed using leaves of H. virescens treated at 0 °C and 25 °C for 12 h, 36 h, and 60 h, respectively, and a total of 9416 DEGs were significantly enriched into seven KEGG pathways. The LC-QTRAP platform was performed using leaves of H. virescens leaves at 0 °C and 25 °C for 12 h, 36 h, and 60 h, respectively, and a total of 1075 metabolites were detected, which were divided into 10 categories. Additionally, 18 major metabolites, two key pathways, and six key genes were mined using a multi-omics analytical strategy. The RT-PCR results showed that with the extension of treatment time, the expression levels of key genes in the treatment group gradually increased, and the difference between the treatment group and the control group was extremely significant. Notably, the functional verification results showed that the key genes positively regulated cold tolerance of H. virescens. These results can lay a foundation for the in-depth analysis of the mechanism of response of perennial herbs to low temperature stress.

Network pharmacology and experimental validation to reveal the target of matrine against PRRSV.

Porcine reproductive and respiratory syndrome (PRRS) is an epidemic animal infectious disease worldwide. In our previous research it was suggested that matrine could inhibit PRRSV infection both in vitro and in vivo, but the antiviral mechanisms are still undecided. Network pharmacology can well solve the difficult problem of "multiple targets, multiple pathways" in the research of TCM action targets. The results of network pharmacology indicated that matrine exerts its anti-PRRSV effect by targeting HSPA8 and HSP90AB1. The results of real-time fluorescent quantitative PCR and western blot showed that infection with PRRSV induced a significant increase in the expression of HSPA8 and HSP90AB1 whereas matrine treatment could significantly reverse it, and the number of viruses of PRRSV also decreased. In this study, the method of network pharmacology was used to explore HSPA8 and HSP90AB1 which were the potential targets of matrine against PRRSV on Marc-145 cells.

Molecular Simulation Study on the Interaction between Porcine CR1-like and C3b.

The molecular basis of porcine red blood cell immune adhesion function stems from the complement receptor type 1-like (CR1-like) on its cell membrane. The ligand for CR1-like is C3b, which is produced by the cleavage of complement C3; however, the molecular mechanism of the immune adhesion of porcine erythrocytes is still unclear. Here, homology modeling was used to construct three-dimensional models of C3b and two fragments of CR1-like. An interaction model of C3b-CR1-like was constructed by molecular docking, and molecular structure optimization was achieved using molecular dynamics simulation. A simulated alanine mutation scan revealed that the amino acids Tyr761, Arg763, Phe765, Thr789, and Val873 of CR1-like SCR 12-14 and the amino acid residues Tyr1210, Asn1244, Val1249, Thr1253, Tyr1267, Val1322, and Val1339 of CR1-like SCR 19-21 are key residues involved in the interaction of porcine C3b with CR1-like. This study investigated the interaction between porcine CR1-like and C3b using molecular simulation to clarify the molecular mechanism of the immune adhesion of porcine erythrocytes.