LRPPRC regulates malignant behaviors, protects mitochondrial homeostasis, mitochondrial function in osteosarcoma and derived cancer stem-like cells.

BACKGROUND: Leucine-rich pentatricopeptide repeat containing (LRPPRC) is a potential oncogene in multiple tumor types, including lung adenocarcinoma, esophageal squamous cell carcinoma and gastric cancer. LRPPRC exerts its tumor-promoting effects mainly by regulating mitochondrial homeostasis and inducing oxidative stress. However, the exact role and mechanisms by which LRPPRC acts in osteosarcoma and osteosarcoma-derived cancer stem-like cells (CSCs), which potentially critically contribute to recurrence, metastasis and chemoresistance, are still largely unclear. METHODS: LRPPRC level in osteosarcoma cells and CSCs were detected by western blot. Effects of LRPPRC on CSCs were accessed after LRPPRC knockdown by introducing lentivirus containing shRNA targeting to LRPPRC mRNA. RESULTS: we found that LRPPRC was highly expressed in several osteosarcoma cell lines and that LRPPRC knockdown inhibited malignant behaviors, including proliferation, invasion, colony formation and tumor formation, in MG63 and U2OS cells. Enriched CSCs derived from MG63 and U2OS cells presented upregulated LRPPRC levels compared to parental cells (PCs), and LRPPRC knockdown markedly decreased the sphere-forming capacity. These findings demonstrate that LRPPRC knockdown decreased stemness in CSCs. Consistent with a previous report, LRPPRC knockdown decreased the expression levels of FOXM1 and its downstream target genes, including PRDX3, MnSOD and catalase, which are responsible for scavenging reactive oxygen species (ROS). Expectedly, LRPPRC knockdown increased the accumulation of ROS in osteosarcoma and osteosarcoma-derived CSCs under hypoxic conditions due to the decrease in ROS scavenging proteins. Moreover, LRPPRC knockdown sensitized osteosarcomas and CSCs against carboplatin, a ROS-inducing chemoagent, and promoted apoptosis. Furthermore, LRPPRC knockdown significantly decreased the mitochondrial membrane potential, disturbed mitochondrial homeostasis and led to mitochondrial dysfunction. CONCLUSION: Taken together, these findings indicated that LRPPRC exerts critical roles in regulating mitochondrial homeostasis, mitochondrial function and tumorigenesis in osteosarcomas and osteosarcoma-derived CSCs. This suggests that LRPPRC might be a promising therapeutic target for osteosarcomas.

A high-sensitivity MEMS gravimeter with a large dynamic range.

Precise measurement of variations in the local gravitational acceleration is valuable for natural hazard forecasting, prospecting, and geophysical studies. Common issues of the present gravimetry technologies include their high cost, high mass, and large volume, which can potentially be solved by micro-electromechanical-system (MEMS) technology. However, the reported MEMS gravimeter does not have a high sensitivity and a large dynamic range comparable with those of the present commercial gravimeters, lowering its practicability and ruling out worldwide deployment. In this paper, we introduce a more practical MEMS gravimeter that has a higher sensitivity of 8 µGal/√Hz and a larger dynamic range of 8000 mGal by using an advanced suspension design and a customized optical displacement transducer. The proposed MEMS gravimeter has performed the co-site earth tides measurement with a commercial superconducting gravimeter GWR iGrav with the results showing a correlation coefficient of 0.91.

Nitric oxide induces monosaccharide accumulation through enzyme S-nitrosylation.

Nitric oxide (NO) is extensively involved in various growth processes and stress responses in plants; however, the regulatory mechanism of NO-modulated cellular sugar metabolism is still largely unknown. Here, we report that NO significantly inhibited monosaccharide catabolism by modulating sugar metabolic enzymes through S-nitrosylation (mainly by oxidizing dihydrolipoamide, a cofactor of pyruvate dehydrogenase). These S-nitrosylation modifications led to a decrease in cellular glycolysis enzymes and ATP synthase activities as well as declines in the content of acetyl coenzyme A, ATP, ADP-glucose and UDP-glucose, which eventually caused polysaccharide-biosynthesis inhibition and monosaccharide accumulation. Plant developmental defects that were caused by high levels of NO included delayed flowering time, retarded root growth and reduced starch granule formation. These phenotypic defects could be mediated by sucrose supplementation, suggesting an essential role of NO-sugar cross-talks in plant growth and development. Our findings suggest that molecular manipulations could be used to improve fruit and vegetable sweetness.

Hypoxia-induced hsa-miR-101 promotes glycolysis by targeting TIGAR mRNA in clear cell renal cell carcinoma.

Increasing evidence suggests that microRNAs (miRNAs) are essential in carcinogenesis, therefore, the present study investigated the role of hsa­miR­101 in renal tumorigenesis and cancer development. On identification of its expression pattern, it may serve as a diagnostic biomarker for clear cell renal cell carcinoma (ccRCC). In the present study, 10 pairs of ccRCC and noncancerous tissue samples were obtained to examine whether the expression of hsa­miR­101 is linked to cancer. The data obtained were validated using reverse transcription­quantitative polymerase chain reaction analysis. The levels of hsa­miR­101 were examined following exposure to hypoxia in ACHN and HK­2 cells. As a predicted target, the mRNA and protein levels of TP53­induced glycolysis and apoptosis regulator (TIGAR) were then assessed. A pcDNA­GFP­miR­101 plasmid was stably transfected into ACHN and HK­2 cells, following which the effects of hsa­miR­101 on the expression of TIGAR and inhibition of glycolysis were investigated. The present study also examined the association between the level of hsa­miR­101 and kidney tumors. It was identified that the expression level was significantly higher in the ccRCC tissues, compared with that in the corresponding noncancerous tissues. The expression values for the upregulated miRNA ranged between 4.6­ and 67.9­fold. On demonstrating the functional link between hypoxia and the expression of miRNAs changes in the expression of hsa­miR­101 were examined following hypoxia exposure in kidney tumor and non­tumor cell lines. It was shown that hypoxia exposure significantly induced hsa­miR­101. The hypoxia­induced upregulation of hsa­miR­101 repressed the activity of TIGAR by targeting TIGAR mRNA and promoting glycolysis. The results showed that the upregulation of hsa­miR­101 in ccRCC was induced by hypoxia. Its expression deceased the protein expression of TIGAR and promoted glycolysis. This regulatory pathway may represent a novel mechanism of carcinogenesis and requires further investigation.

Preparation, characterization and in vivo pharmacokinetic study of PVP-modified oleanolic acid liposomes.

The primary purpose of the present study was to design and optimize a liposomal formulation of the poorly water-soluble drug oleanolic acid (OA) to improve its oral bioavailability, and prolong the duration of therapeutic drug level. Liposomes containing a soybean lecithin and cholesterol lipid bilayer, a protective hydrophilic polyvinylpyrrolidone-K30 (PVP-K30) coating, and a protective bile salt, sodium deoxycholate, were prepared by a thin-film dispersion method coupled with sonication. Several properties of the PVP-modified OA liposomes (PVPOALs), including surface morphology, particle size, zeta potential and entrapment efficiency were extensively characterized. The pharmacokinetic parameters of PVPOALs in rats were determined by UPLC-MS/MS following oral administration. The results of the characterization studies demonstrated that PVPOALs were spherical particles with an average particle size of 179.4nm and a zeta potential of -28.8mV. The drug encapsulation efficiency was more than 90%. After freeze-drying, the prepared liposomes possessed high entrapment efficiency of more than 90%. The mean particle size was 194.8nm, and the zeta potential was about -30.9mV. Furthermore, as compared to the commercial tablets, the liposomal formulation enhanced the maximum plasma concentration (Cmax) of OA by 6.90-fold in rat plasma. The relative bioavailability of PVP-modified liposomes was 607.9%. The research work in the paper suggests that PVP-modified liposomes could serve as a practical oral preparation for OA in future cancer therapy.

Mitochondrion-Permeable Antioxidants to Treat ROS-Burst-Mediated Acute Diseases.

Reactive oxygen species (ROS) play a crucial role in the inflammatory response and cytokine outbreak, such as during virus infections, diabetes, cancer, cardiovascular diseases, and neurodegenerative diseases. Therefore, antioxidant is an important medicine to ROS-related diseases. For example, ascorbic acid (vitamin C, VC) was suggested as the candidate antioxidant to treat multiple diseases. However, long-term use of high-dose VC causes many side effects. In this review, we compare and analyze all kinds of mitochondrion-permeable antioxidants, including edaravone, idebenone, α-Lipoic acid, carotenoids, vitamin E, and coenzyme Q10, and mitochondria-targeted antioxidants MitoQ and SkQ and propose astaxanthin (a special carotenoid) to be the best antioxidant for ROS-burst-mediated acute diseases, like avian influenza infection and ischemia-reperfusion. Nevertheless, astaxanthins are so unstable that most of them are inactivated after oral administration. Therefore, astaxanthin injection is suggested hypothetically. The drawbacks of the antioxidants are also reviewed, which limit the use of antioxidants as coadjuvants in the treatment of ROS-associated disorders.

Antiviral and antitumor activities of the lectin extracted from Aspidistra elatior.

Lectins, a group of highly diverse proteins of non-immune origin and are ubiquitously distributed in plants, animals and fungi, have multiple significant biological functions, such as anti-fungal, anti-viral and, most notably, anti-tumor activities. A lectin was purified from the rhizomes of Aspidistra elatior Blume, named A. elatior lectin (AEL). In vitro experiments showed that the minimum inhibitory concentrations of AEL against the vesicular stomatitis virus, Coxsackie virus B4, and respiratory syncytial virus were all the same at about 4 µg/mL. However, AEL was ineffective against the Sindbis virus and reovirus-1. AEL also showed significant in vitro antiproliferative activity towards Bre-04, Lu-04, HepG2, and Pro-01 tumor cell lines by increasing the proportion of their sub-G1 phase. However, AEL failed to restrict the proliferation of the HeLa cell line. Western blotting indicated that AEL induced the upregulation of cell cycle-related proteins p53 and p21. The molecular basis and species-specific effectiveness of the anti-proliferative and anti-viral potential of AEL are discussed.

[Validation on the elimination of neonatal tetanus programs through Lot Quality Assurance-Cluster Sample Survey in China].

OBJECTIVE: Field surveys were performed under WHO recommended validation procedures, using the Lot Quality Assurance-Cluster Sample(LQA-CS)method to validate the elimination status regarding neonatal tetanus in China. METHODS: LQA-CS surveys were conducted in two areas under the highest risk of neonatal tetanus-Jiangmen prefecture in Guangdong and Hechi in Guangxi. Random sampling method was conducted on 96 survey clusters in each prefecture with 12 eligible live births(live birth born one year before the survey)for each cluster, by trained investigators. RESULTS: There were 1 153 eligible live births from 23 465 families surveyed in Jiangmen and 1 152 eligible live births from 21 623 families being studied in Hechi. All the indices on quality control were strictly followed. There was no neonatal tetanus case which met the criteria of neonatal elimination found in either of the areas. Data showed that neonatal tetanus had been eliminated in both Jiangmen and Hechi cities. CONCLUSION: Since both Jiangmen and Hechi were cities having the highest-risk in China, it was most likely that neonatal tetanus had also been eliminated in other prefectures at lower risk. Elimination programs on MNT was therefore considered validate in China when the study was carried out. However, the achievements needed to be maintained.

[The method and efficacy for screening neonatal tetanus in high risk areas in China].

OBJECTIVES: To establish a method for screening neonatal tetanus (NT) in high risk areas in China using multi-sources data. METHODS: We adopted six NT-related indicators from National Notifiable Disease Report System (NNDRS) and National Maternal and Child Health Annual Report System, to calculate weighted high-risk score at prefecture level in 2010 and 2011. And we selected the top 30 high risk cities, and compared the scores with the actual NT incidence ranking and WHO scoring. RESULTS: The highest areas distributed in the Southwest of China with poor and minority population, and the Southeast part with high density of migrants. In the leading 30 prefectures with high score between the methods of weighted high-risk scoring and reported NT incidence ranking, there were 8 different. In comparison of the results of the methods of weighed high-risk scoring and WHO scoring, 276 prefectures in 340 distributed were divided into the same ranking groups, with Kappa coefficient 0.56 (P < 0.01). The Chi-Square association coefficient was 0.74 (P < 0.01), which showed a high correlation. But there were 10 different prefectures in the leading 36 prefectures between the two methods. CONCLUSION: The weighted scoring method included several possible factors influencing NT incidence and took their weights into consideration. Thereby, compared with WHO scoring method, this method could be more appropriate for the reality in China.

A single leaf of Camellia oleifera has two types of carbon assimilation pathway, C(3) and crassulacean acid metabolism.

The C(4) plants, whose first product of photosynthetic CO(2) fixation is a four-carbon acid, have evolved independently many times. Crassulacean acid metabolism (CAM) is a biological mechanism known to exhibit some C(4) characteristics such as the C(3) cycle during daylight and demonstrates the C(4) cycle at night. There are also various C(3)-CAM intermediates, whose CAM pathway can be induced by environmental changes. However, neither fungus-induced CAM nor Theaceae CAM have been reported previously. Here, we show that CAM could be generated by fungus infection in Camellia oleifera Abel. young leaves, even at a location of a single leaf where the upper part had been transformed into a succulent one, while the lower part remained unchanged. The early photosynthetic products of dark-grown C. oleifera succulent leaves were malate, whereas C. oleifera normal leaves and light-grown succulent leaves incorporated most of (14)C into the primary photosynthetic product 3-phosphoglycerate. Camellia oleifera succulent leaves have a lower absolute δ(13)C value, much lower photorespiration rates and lower transpiration rates during the day than those of C. oleifera normal leaves. Like a typical CAM plant, stomata of C. oleifera succulent leaves closed during the daylight, but opened at night, and therefore had a detectable CO(2) compensation point in darkness. Net photosynthetic rates (P(n)) fluctuated diurnally and similarly with stomatal aperture. No light intensity saturation could be defined for C. oleifera succulent leaves. C(4) key enzymes in C. oleifera succulent leaves were increased at both the transcriptional/translational levels as well as at the enzyme activity level.

Tobacco advertising, environmental smoking bans, and smoking in Chinese urban areas.

OBJECTIVES: To evaluate whether cigarette smoking in Chinese urban areas was respectively associated with exposure to tobacco advertising and smoking bans in households, workplaces, and public places. METHODS: Participants were 4735 urban residents aged 15 years and older, who were identified through multi-stage quota-sampling conducted in six Chinese cities. Data were collected on individual sociodemographics and smoking status, and regional tobacco control measures. The sample was characterized in terms of smoking prevalence, and multilevel logistic models were employed to analyze the association between smoking and tobacco advertising and environmental smoking restrictions, respectively. RESULTS: Smoking prevalence was 30%. Multilevel logistic regression analysis showed that smoking was positively associated with exposure to tobacco advertising, and negatively associated with workplace and household smoking bans. CONCLUSIONS: The association of smoking with both tobacco advertising and environmental smoking bans further justifies implementation of comprehensive smoking interventions and tobacco control programs in China.

Mental health status and related characteristics of Chinese male rural-urban migrant workers.

To explore mental health status and related characteristics in a sample of Chinese male rural-urban migrants. Subjects were 1,595 male rural-urban migrant workers selected though a multi-stage sample survey conducted in two cities (Hangzhou and Guangzhou). Data were collected by means of a self-administered questionnaire. Both life and work stressors were examined. Stress and mental health status were measured by the Chinese Perceived Stress Scale (CPSS) and the Chinese Health Questionnaire (CHQ), respectively. Unconditional logistic regression analysis was performed to identify factors associated with probable mental disorders. There are approximately 120 million rural-urban migrants in China. The prevalence of probable mental disorders in the sample population was 24.4% (95% CI: 23.3-25.5%), which was higher than among urban residents (20.2%, 95% CI: 18.8-21.7%). Logistic regression analysis revealed that five characteristics were positively associated with risk for probable mental disorders: originating in the South (OR = 2.00; 95% CI = 1.02, 4.00), higher life stress (OR = 7.63; 95% CI = 5.88, 10.00), staying in the city for 5-9 months each year (OR = 2.56; 95% CI = 1.67, 3.85), higher work stress (OR = 2.56; 95% CI = 1.96, 3.33), and separation from wife (OR = 2.43; 95% CI = 1.61, 3.57). Employment in machinery and transportation (OR = 0.54; 95% CI = 0.36, 0.81) and higher self-worth (OR = 0.42; 95% CI = 0.28, 0.62) were negatively associated. Findings support an urgent need to develop specific policies and programs to address mental health problems among Chinese rural-urban migrants.

A tetrahedron beam computed tomography benchtop system with a multiple pixel field emission x-ray tube.

PURPOSE: To demonstrate the feasibility of Tetrahedron Beam Computed Tomography (TBCT) using a carbon nanotube (CNT) multiple pixel field emission x-ray (MPFEX) tube. METHODS: A multiple pixel x-ray source facilitates the creation of novel x-ray imaging modalities. In a previous publication, the authors proposed a Tetrahedron Beam Computed Tomography (TBCT) imaging system which comprises a linear source array and a linear detector array that are orthogonal to each other. TBCT is expected to reduce scatter compared with Cone Beam Computed Tomography (CBCT) and to have better detector performance. Therefore, it may produce improved image quality for image guided radiotherapy. In this study, a TBCT benchtop system has been developed with an MPFEX tube. The tube has 75 CNT cold cathodes, which generate 75 x-ray focal spots on an elongated anode, and has 4 mm pixel spacing. An in-house-developed, 5-row CT detector array using silicon photodiodes and CdWO(4) scintillators was employed in the system. Hardware and software were developed for tube control and detector data acquisition. The raw data were preprocessed for beam hardening and detector response linearity and were reconstructed with an FDK-based image reconstruction algorithm. RESULTS: The focal spots were measured at about 1 × 2 mm(2) using a star phantom. Each cathode generates around 3 mA cathode current with 2190 V gate voltage. The benchtop system is able to perform TBCT scans with a prolonged scanning time. Images of a commercial CT phantom were successfully acquired. CONCLUSIONS: A prototype system was developed, and preliminary phantom images were successfully acquired. MPFEX is a promising x-ray source for TBCT. Further improvement of tube output is needed in order for it to be used in clinical TBCT systems.

Red blood cell extrudes nucleus and mitochondria against oxidative stress.

Mammal red blood cells (erythrocytes) contain neither nucleus nor mitochondria. Traditional theory suggests that the presence of a nucleus would prevent big nucleated erythrocytes to squeeze through these small capillaries. However, nucleus is too small to hinder erythrocyte deformation. And, there is no sound reason to abandon mitochondria for the living cells. Here, we found that mammal erythrocyte reactive oxygen species (ROS) levels kept stable under diabetes, ischemia reperfusion, and malaria conditions or in vitro sugar/heme treatments, whereas bird erythrocyte ROS levels increased dramatically in these circumstances. Nuclear and mitochondrial extrusion may help mammal erythrocytes to better adapt to high-sugar and high-heme conditions by limiting ROS generation.

Effects of household, workplace, and public place smoking restrictions on smoking cessation.

The aim of this study was to evaluate the association between environmental smoking restrictions, distinguished by site, and smoking cessation by Chinese urban residents. Recruited through multi-stage quota-sampling, residents in six Chinese cities were surveyed. Data were both individual-level and city-level. Among 4735 respondents, 715 were identified as successful quitters and 405 as unsuccessful. Multilevel logistic regression analysis showed smoking cessation to be associated with city-level public place and workplace restrictions and individual-level workplace and household restrictions. Results offer justification for decision-makers to implement environmental tobacco control policies and related public health interventions aimed at markedly diminishing the high smoking prevalence in China.

Mg-protoporphyrin, haem and sugar signals double cellular total RNA against herbicide and high-light-derived oxidative stress.

Cellular total RNA level is usually stable, although it may increase gradually during growth or seed germination, or decrease gradually under environmental stresses. However, we found that plant cell RNA could be doubled within 48 h in response to herbicide-induced Mg-protoporphyrin and heme accumulation or a high level of sugar treatment. This rapid RNA multiplication is important for effective cellular resistance to oxidative stress, such as high-light and herbicide co-stress conditions, where the plastid-signalling defective mutant gun1 shows an apparent phenotype (more severe photobleaching). Hexokinase is required for sugar-induced RNA multiplication. While both sugar and Mg-protoporphyrin IX require plastid protein GUN1 and a nuclear transcription factor ABI4, haem appears to function through an independent pathway to control RNA multiplication. The transcription co-factor CAAT binding protein mediates the rapid RNA multiplication in plant cells in all the cases.

Tetrahedron beam computed tomography (TBCT): a new design of volumetric CT system.

Volumetric CT imaging systems usually comprise a point x-ray source and a 2D detector. Flat panel imager (FPI)-based cone beam CT (CBCT) has become an important online imaging modality for image-guided radiotherapy and intervention. However, due to excessive scatter photons and inferior detector performance, the image quality of current CBCT is significantly inferior to diagnostic fan-beam CT. We propose a novel tetrahedron beam computed tomography (TBCT) imaging system which consists of a linear scan x-ray source and a linear x-ray detector array. The linear x-ray tube and detector array are aligned perpendicular and parallel to the rotation plane, respectively. The x-ray beams are narrowly collimated into fan beams and focused on the linear detector array. The linear detector and linear x-ray source form a 'tetrahedron' volume instead of a 'cone' volume. TBCT is similar to CBCT in image reconstruction geometry; however, its image quality will be significantly superior to that of CBCT due to its scatter rejection mechanism and the use of high-performance discrete x-ray detectors. In this paper, we describe the design of the TBCT system for image-guided radiotherapy and some results of preliminary studies.

Preparation and characterization of a novel recombinant human parathyroid hormone (1-34) analog (Gly1-Gln26-rhPTH(1-34)) with enhanced biological activity.

A recombinant human parathyroid hormone (rhPTH) fragment (Gly1-Gln26-rhPTH(1-34)) which contains two amino acids substitutions (Gly1 and Gln26) was acquired through Escherichia coli expression system using a soluble fusion protein strategy. The soluble fusion protein MBP-Gly1-Gln26-rhPTH(1-34) was harvested after purification by Phenyl-Sepharose F.F and Q-Sepharose F.F chromatographies. Following tobacco etch virus (TEV) protease cleavage and further purification by SP-Sepharose F.F chromatography, 30.8 mg/L Gly1-Gln26-rhPTH(1-34) without tag was obtained with high purity up to 99%. Cyclic AMP (cAMP) stimulation assay suggested that Gly1-Gln26-rhPTH(1-34) could increase the biological activity by up to 13.89% and 6.34%. After daily subcutaneous injection (for 13 weeks) of 5, 10 and 20 microg of Gly1-Gln26-rhPTH(1-34)/1000g body weight, the mean Bone Material Density (BMD) of ovariectomized (OVXed) rats increased to 7.95-30.54% and 1.98-23.32%, compared to control-vehicle group (OVX, P<0.001) and sham- operated group (SHAM, P<0.01), respectively.

Apoptosis-inducing effect and structural basis of Polygonatum cyrtonema lectin and chemical modification properties on its mannose-binding sites.

Polygonatum cyrtonema Lectin (PCL), which is classified as a monocot mannose-binding lectin, has received great regards for its uniquely biological activities and potentially medical applications in cancer cells. This paper was initially aimed to study apoptosis of PCL on Hela cells. Thus, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) method was carried out. Through observation of cell morphologic changes and Lactate dehydrogenase (LDH) activity-based cytotoxicity assays, PCL induced HeLa cell apoptosis in a dose-dependent manner. To further gain structural basis, multiple alignments, homology modeling and docking experiments were performed to analyze the correlation between its biological activities and mannose-binding sites. Eventually, considering docking data, chemical modification properties on the three mannose-binding sites were analyzed by a series of biological experiments (e.g., hemagglutinating and mitogenic activity assays, fluorescence and Circular Dichrosim (CD) spectroscopy) to profoundly identify the role of some key amino acids in the structure-function relationship of PCL.

Hemagglutinating activity and conformation of a lactose-binding lectin from mushroom Agrocybe cylindracea.

A lactose-binding lectin (Agrocybe cylindracea Lectin, ACL) purified from fruiting bodies of the mushroom A. cylindracea was investigated to determine the hemagglutinating activity and conformation changes after chemical modification, removal of metal ion and treatment at different temperatures and pH. ACL agglutinated both rabbit and human erythrocytes and its hemagglutinating activity could be inhibited by lactose. This lectin was stable in the pH range of 6-9 and temperature up to 60 degrees C. Fluorescence quenching and modification of tryptophan residues indicated that there were about two tryptophan residues in ACL molecule and one of them might be located on the surface, while the other was buried in the hydrophobic shallow groove near the surface. Chemical modification of serine/threonine and histidine showed that the partial necessity of these residues for the hemagglutinating activity of ACL. However, modifications of arginine, tyrosine and cysteine residues had no effect on its agglutinating activity.