MORPHOLOGY,FINE STRUCTURE AND ONTOGENY OF THE STINGING EMERGENCE OF TRAGIA RAMOSA AND T. SAXICOLA (EUPHORBIACEAE)

The ontogeny and ultrastructure of Tragia ramosa and T. saxicola are described. The stinging emergence of T. ramosa and T. saxicola consists of a central stinging cell and three lateral cells. The stinging cell possesses a compound crystal in the apical region which is held in place by cell wall extensions. The stinging cell cytoplasm is characterized by a large central vacuole which contains a proteinaceous substance as determined histochemically. Upon contact, the stinging cell wall is pushed back over the crystal, exposing it to penetrate an individual. This stinging mechanism is unique among stinging emergences. The stinging cell is subepidermal in origin whereas the three lateral cells are epidermal in origin. The morphology, ultrastructure and ontogeny of the stinging emergence of T. ramosa and T. saxicola appear to be identical.     

Ultrastructural evidence for uptake of silicon-containing silicic acid analogs byUrtica pilulifera and incorporation into cell wall silica

Summary In natural environments the stinging nettle plant,Urtica pilulifera, bears stinging cells in which electron dense silica deposits occupy a significant volume of the cell wall. Plants were grown in hydroponic solutions with and without supplements of silicic acid, the chemical form of silicon available to biological systems to determine if this plant and the stinging cells will grow normally under conditions of silicon starvation. In separate experiments, several analogs of silicic acid were added as supplements to the hydroponic solution to determine whether silicic acid binding sites had detectably different specificities for the different molecular structures of the analogs. The analogs [(R-)_nSi(-OH)_m] have the following structures (R, n, m): (1)-H, 1, 3; (2)-CH₃, 1, 3; (3)-CH₃, 2, 2; (4)-CH₃, 3, 1; (5)-CH₂CH₃, 1, 3; and (6)-C₆H₅, 1, 3. Electron microscopy was used as an assay for the uptake and incorporation of analogs into an electron dense silica-like product in the stinging cell wall. The results indicate that cell wall silica production occurred only when the analog contained at least three hydroxyl groups. The morphology and ontogeny of the plant was normal except for: 1, the appearance of green spots on the leaves when the analog contained two or more hydroxyl groups, and 2, total blockage of flowering by the two methyl derivative of silicic acid, (CH₃)₂Si(OH)₂.     

Ontogeny of external glands in the bladderwortUtricularia monanthos

Summary The development of external glands on traps and stolons ofU. monanthos has been studied using transmission electron microscopy. During early differentiation of the epidermis some cells remain narrow and develop a protuberance which subsequently divides into a terminal and a pedestal cell, with the remainder of the original cell forming the basal epidermal cell of the gland. The lateral wall of the pedestal cell soon becomes densely impregnated throughout its thickness, and this is followed by the formation of discontinuous cuticular deposits within the primary wall of the terminal cell. The outer wall of the terminal cell then usually undergoes extensive secondary wall thickening beginning with the formation of ingrowths which for a period characterize the cell as a transfer cell. Later, at the stage when traps begin capturing prey, these ingrowths are overlain by further layers of secondary wall material. Concomitantly, in the pedestal cell, wall ingrowths become fully differentiated on the outer transverse wall and persist throughout the remaining life of the gland.The function of external glands during early ontogeny is discussed. At the stage when the terminal cell is differentiated as a transfer cell it is suggested that the gland is mainly responsible for absorbing solutes from the external medium. Once traps commence capturing prey the gland may become modified for a rôle in water secretion, facilitated by the differentiation of the pedestal cell as a transfer cell, and by the formation of a thick outer wall in the terminal cell.     

The ability of an attaching and effacing pathogen to trigger localized actin assembly contributes to virulence by promoting mucosal attachment

Enterohaemorrhagic Escherichia coli (EHEC) colonizes the intestine and causes bloody diarrhoea and kidney failure by producing Shiga toxin. Upon binding intestinal cells, EHEC triggers a change in host cell shape, generating actin ‘pedestals’ beneath bound bacteria. To investigate the importance of pedestal formation to disease, we infected genetically engineered mice incapable of supporting pedestal formation by an EHEC‐like mouse pathogen, or wild type mice with a mutant of that pathogen incapable of generating pedestals. We found that pedestal formation promotes attachment of bacteria to the intestinal mucosa and vastly increases the severity of Shiga toxin‐mediated disease.     

Fine Structure of a Silica-Biomineralizing Testate Amoeba,Netzelia tuberculata1

The fine structure of the cytoplasm and the intracytoplasmic origin of siliceous granules and surrounding cement plaques used in constructing the shell wall of Netzelia tuberculata are described. These organisms construct their test from biogenic siliceous particles and sand grains or other foreign particles (including starch grains apparently from algal prey) coated with biogenic silica. The smooth surface texture of the grains, compared to those of other particle-gathering testate amoebae, can be expalained by the deposition of a thin surface layer of silica on the foreign particles incorporated into the wall.     

Pedestal hairs of the ant Echinopla melanarctos (Hymenoptera, Formicidae): morphology and functional aspects

The South East Asian arboreal Formicine Echinopla melanarctos, as well as some other members of this genus possess a cuticular structure unique in ants, the pedestal hairs. In E. melanarctos, about 700 pedestal hairs are situated on the dorsal and lateral surfaces of the head, the alitrunk, the petiole and the gaster. They are arranged in a polygon-like figuration. On the summit of each of the up to 200-μm high pedestals, a single central hair inserts. This hair (up to 500-μm long) is innervated by a single bipolar mechanosensitive sensory cell. The lumen of each tube-like pedestal contains (1) epithelial cells (2) the sensory cell and the auxiliary cells of the central hair and (3) the long efferent ductules of up to ten isolated bicellular glandular units. Each glandular unit is composed of a secretory glandular cell and a duct cell, all of which are located at the base of a pedestal. The cytoplasm of a glandular cell contains a well-developed end apparatus and is characterised by stacks of smooth and granular endoplasmic reticulum, numerous polyribosomes, a lot of mitochondria and some up to 5-μm large secretory vesicles. The secretion of the gland cells is released on the apex of the pedestal wall via small pores. Approximately 30 μm below their summit, some pedestals possess additionally (up to six) mechanosensitive hairs that are arranged ray-like. We suppose that the pedestal hairs are important in nest-space protection and find that only in ants with high pedestals on the head (Echinopla melanarctos and Echinopla pallipes), the compound eyes are stalked thus overtopping the pedestals.     

STUDIES ON THE BIOCHEMISTRY AND FINE STRUCTURE OF SILICA SHELL FORMATION IN DIATOMS. II. THE STRUCTURE OF THE CELL WALL OF NAVICULA PELLICULOSA (BRÉB.) HILSE

The cell wall of the freshwater diatom Navicula pelliculosa (Bréb.) Hilse is composed of the silica shell and an organic skin which surrounds it. Isolated skins can be prepared by first removing the contents of the cell by mechanical shaking, followed by a posttreatment of these isolated cell walls with HF vapor to remove the silica shell. T h e skins can also be seen in sections, particularly well after the silica shell has been removed B y H. F; vapor. The origin and morphological composition of the shin in N. pelliculosa are not yet completely ascertaincd. As parts of the cell wn11, both the silica shell and the skin are extracellularly located. The growth of the silica shell, however, occurs intracellularly inside a vesicle delimited by a triple-layered membrane, the silicalemma. This membrane or secondary excreted organic material or both in various proportions may compose the skin.     

ULTRASTRUCTURE OF THE CONCHOCELIS STAGE OF THE MARINE RED ALGA PORPHYRA LEUCOSTICTA1

The ultrastructure of the Conchocelis or filamentous stage of Porphyra leucosticta was investigated. Each cell contains 1 or 2 parietal, stellate chloroplasts with a single pyrenoid in each chloroplast. The centrally located nucleus is irregularly shaped and contains 1–2 nucleoli. The cytoplasm has typical floridean starch grains and nonmernbrane-bound lipid bodies. The cell wall is divided into an outer and an inner wall. Many lomasomes are associated with the cell membrane. Pit connections are found between cells, and their taxonomic significance is discussed.     

THE BLOCHMANN BODIES: HEREDITARY INTRACELLULAR SYMBIONTS OF INSECTS

The term ‘Blochmann body’ was originated by Wheeler in 1889 for bacteria-like particles in the cytoplasm of cockroach eggs. These particles can be traced during embryonic development to definitive somatic cells, the mycetocytes. These and similar particles of other insects have so far not been cultivated in bacteriological media nor injected into host animals to produce either pathological or benign infections. Their structure and composition indicate them to be evolutionary descendants of free-living micro-organisms; operationally, they appear to belong to the class of cell particles designated by Lederberg (1952) as plasmids. Genetic studies have shown the Blochmann bodies to be transmitted through the maternal line. Their presence in the egg cytoplasm at some stage in oocyte development is easily demonstrated, but studies by a number of workers have so far yielded a variety of conflicting claims or suggestions as to how the particles get into the germ cells or oocytes. The Blochmann particles of cockroaches, besides existing in the mycetocytes and eggs, occur embedded in a dense tangle of microvilli which are extensions of the plasma membrane of young oocytes. Essentially particle-free strains of cockroaches can be produced by feeding aureo-mycin or high levels of urea, or by withholding manganese. The effect is produced only by treating females, and is delayed one generation. In generations following the first (symbiont-free) generation, the Blochmann symbionts gradually reappear, suggesting that elimination was not absolute. Blochmann bodies in both the mycetocytes and the ovarioles of the cockroach carry out oxidative metabolism, as indicated by their ability to reduce tetrazolium. Glycolysis has not been demonstrated. The generalization that symbionts of the Blochmann type represent an adaptation to compensate for dietary deficiencies is inapplicable, since deficiencies have not been demonstrated for the diets of cockroaches, weevils, or homopterans—the major insect groups in which the symbionts occur. The symbionts of cockroaches and homopterans appear to be involved in the utilization of nitrogenous waste products in synthetic metabolism. In most instances the Blochmann bodies lack the central nucleoid body characteristic of the growing phase of free-living bacteria, thus resembling the Kappa and Mu particles of Paramecium and the endosymbiont of the protozoan Crithidia oncopelti. Both histochemical tests and electron-microscope studies indicate a DNA component that is widely dispersed within the particle. Blochmann bodies are without internal cristae. The cockroach symbionts contain muramic acid, a diagnostic feature of the cell wall of bacteria. Response to various nuclear and cytoplasmic reagents is intermediate between those of typical mitochondria and free-living bacteria. The envelopes of the Blochmann particles are generally thinner than those of free-living bacteria. The function of plasmids of the Blochmann type may be that they, like the bacteroids of the Rhixobium-legume symbiosis, extend the range of metabolic potential of the host cell by a process of mutual host-symbiont adjustment. Possible roles could be subsumed under the headings of bacteria-like, mitochondria-like, or nucleus-like functions.     

THE POLYMORPHIC DIATOM PHAEODACTYLUM TRICORNUTUM: ULTRASTRUCTURE OF ITS MORPHOTYPES1,2

The ultrastructure of the oval, fusiform and triradiate morphotypes of Phaeodactylum tricornutum Bohlin is described. The organization and structure of the cytoplasmic organelles is similar in all three morphotypes, except that the vacuoles occupy the extra volume created by the arms of the fusiform and triradiate cells. The frustule in fusiform and triradiate cells is organic; in the oval type it may be organic or one of the valves may have a silica frustule surrounded by an organic wall. In all cells, the organic cell wall has up to 10 silica bands (13 nm wide) embedded in its surface in the girdle region, lacks girdle bands, and has an outer corrugated cell wall layer, except in the girdle region. Cell division, organic wall formation and silica deposition are described in detail. Four types of oval cells are also described. The relation to other diatoms is discussed.     

Silicon enhances growth independent of silica deposition in a low-silica rice mutant, lsi1

To examine whether silica bodies are essential for silicon-enhanced growth of rice seedlings, we investigated the response of rice, Oryza sativa L., to silicon treatment. Silicic acid treatment markedly enhanced the SPAD (soil plant analytical development) values of leaf blades and the growth and development of leaves and lateral roots in cvs. Hinohikari and Oochikara, and a low-silicon mutant, lsi1. Combination of ethanol–benzene displacement and staining with crystal violet lactone enabled more detailed histochemical analysis to visualize silica bodies in the epidermis under bright-field microscopy. Supply of silicon induced the development of motor cells and silica bodies in epidermal cells in Hinohikari and Oochikara but not or marginal in lsi1. X-ray analytical microscopy detected silicon specifically in the leaf sheath, the outermost part of the stem, and the leaf blade midrib, suggesting that silicon is distributed to tissues involved in maintaining rigidity of the plant to prevent lodging, rather than being passively deposited in growing tissues. Silicon supplied at high dose accumulated in all rice seedlings and enhanced growth and SPAD values with or without silica body formation. Silicon accumulated in the cell wall may play an important physiological role different from that played by the silica deposited in the motor cell and silica bodies.     

NANOSTRUCTURE OF THE DIATOM FRUSTULE AS REVEALED BY ATOMIC FORCE AND SCANNING ELECTRON MICROSCOPY

The cell wall (frustule) of the freshwater diatom Pinnularia viridis (Nitzsch) Ehrenberg is composed of an assembly of highly silicified components and associated organic layers. We used atomic force microscopy (AFM) to investigate the nanostructure and relationship between the outermost surface organics and the siliceous frustule components of live diatoms under natural hydrated conditions. Contact mode AFM imaging revealed that the walls were coated in a thick mucilaginous material that was interrupted only in the vicinity of the raphe fissure. Analysis of this mucilage by force mode AFM demonstrated it to be a nonadhesive, soft, and compressible material. Application of greater force to the sample during repeated scanning enabled the mucilage to be swept from the hard underlying siliceous components and piled into columns on either side of the scan area by the scanning action of the tip. The mucilage columns remained intact for several hours without dissolving or settling back onto the cleaned valve surface, thereby revealing a cohesiveness that suggested a degree of cross-linking. The hard silicified surfaces of the diatom frustule appeared to be relatively smooth when living cells were imaged by AFM or when field-emission SEM was used to image chemically cleaned walls. AFM analysis of P. viridis frustules cleaved in cross-section revealed the nanostructure of the valve silica to be composed of a conglomerate of packed silica spheres that were 44.8 ± 0.7 nm in diameter. The silica spheres that comprised the girdle band biosilica were 40.3 ± 0.8 nm in diameter. Analysis of another heavily silicified diatom, Hantzschia amphioxys (Ehrenberg) Grunow, showed that the valve biosilica was composed of packed silica spheres that were 37.1 ± 1.4 nm and that silica particles from the girdle bands were 38.1 ± 0.5 nm. These results showed little variation in the size range of the silica particles within a particular frustule component (valve or girdle band), but there may be differences in particle size between these components within a diatom frustule and significant differences are found between species.     

Organization of mature external glands on the trap and other organs of the bladderwortUtricularia monanthos

Summary The mature dome-shaped glands which cover the outer surfaces of the trap, leaves, anchor and runner stolons inU. monanthos are described using conventional and some high voltage transmission electron microscopy. The glands occur as scattered ordinary external glands and as a compact clump of vestibule glands at the entrance to the doorway. Each gland rests on a basal epidermal cell and consists of a single pedestal and terminal cell. Vestibule and leaf glands differ slightly from the other glands mainly in the structure of the outer wall of the terminal cell. Nuclear crystals are prominent and the cytoplasm of the pedestal and terminal cells contains tubular structures usually aggregated near the nucleus. The pedestal cell is a transfer cell with short wall protuberances on the outer wall, conspicuous mitochondria and a heavily impregnated lateral wall.The terminal cell often has an outer wall that is greatly thickened and a protoplast that may degenerate early. In the most developed cells the protoplast remains active for a long period and the outer wall is differentiated into several layers. The outermost layer is cuticularized consisting of an open meshwork of deposits. In leaf glands a local polysaccharide mass is usually developed within the cuticularized region. The inner non-impregnated region of the outer wall may show four layers. In vestibule glands fewer layers are present and the wall shows prominent lamellations. Some ordinary external glands differentiate a sponge-like substructure within the inner wall.The ultrastructure and function of the glands are discussed. We support the concept that mature external glands are responsible for secreting water, with those on traps being particularly active during the resetting of the organ. Our work provides a structural basis for recent suggestions by other workers that the mechanism of secretion probably involves establishing a standing osmotic gradient within the gland.     

Bt toxin is not taken up from soil or hydroponic culture by corn,carrot, radish,or turnip

The culture of transgenic Bt corn (Zea mays L.) has resulted in concern about the uptake of the Cry1Ab protein toxin by crops subsequently grown in soils in which Bt corn has been grown. The toxin released to soil in root exudates of Bt corn, from the degradation of the biomass of Bt corn, or as purified toxin, was not taken up from soil, where the toxin is bound on surface-active particles (e.g. clays and humic substances), or from hydroponic culture, where the toxin is not bound on particles, by non-Bt corn, carrot (Daucus carota L.), radish (Raphanus sativus L.), and turnip (Brassica rapa L.). The persistence of the toxin in soil for 90 days after its addition in purified form or for 120–180 days after its release in exudates or from biomass, the longest times evaluated, confirmed that the toxin was bound on surface-active particles in soil, which protected the toxin from biodegradation. The greater toxicity of the toxin in soil amended with 9% montmorillonite or kaolinite than in soil amended with 3% of these clay minerals indicated that the binding and persistence of the toxin increased as the clay concentration was increased.     

Cwl0971, a novel peptidoglycan hydrolase,plays pleiotropic roles in Clostridioides difficile R20291

Clostridioides difficile is a Gram-positive, spore-forming, toxin-producing anaerobe that can cause nosocomial antibiotic-associated intestinal disease. Although the production of toxin A (TcdA) and toxin B (TcdB) contribute to the main pathogenesis of C. difficile, the mechanism of TcdA and TcdB release from cell remains unclear. In this study, we identified and characterized a new cell wall hydrolase Cwl0971 (CDR20291_0971) from C. difficile R20291, which is involved in bacterial autolysis. The gene 0971 deletion mutant (R20291Δ0971) generated with CRISPR-AsCpfI exhibited significantly delayed cell autolysis and increased cell viability compared to R20291, and the purified Cwl0971 exhibited hydrolase activity for Bacillus subtilis cell wall. Meanwhile, 0971 gene deletion impaired TcdA and TcdB release due to the decreased cell autolysis in the stationary/late phase of cell growth. Moreover, sporulation of the mutant strain decreased significantly compared to the wild type strain. In vivo, the defect of Cwl0971 decreased fitness over the parent strain in a mouse infection model. Collectively, Cwl0971 is involved in cell wall lysis and cell viability, which affects toxin release, sporulation, germination, and pathogenicity of R20291, indicating that Cwl0971 could be an attractive target for C. difficile infection therapeutics and prophylactics.     

DEVELOPMENT OF WHEAT (TRITICUM AESTIVUM) POLLEN. II. HISTOCHEMICAL DIFFERENTIATION OF WALL AND UBISCH BODIES DURING DEVELOPMENT

The histochemistry of different developmental stages of the pollen wall, aperture, and Ubisch bodies of Triticum aestivum is examined with light and transmission electron microscopy. Various parts of the callosic envelope of the tetrad spores stain differentially. At the late tetrad stage, the probacules and the coat of pro-Ubisch bodies are densely stained for acidic polysaccharides, protein, and neutral polysaccharides. The protectum and the core of pro-Ubisch bodies are moderately stained. Upon release of microspores from the callosic cell envelope, the stainability for acidic polysaccharides increases in the exine and in the wall of Ubisch bodies, becoming very intense in the wall of mature pollen grains and Ubisch bodies. The stainability for neutral polysaccharides is decreased in the mature pollen wall and in the Ubisch bodies, while the stainability for protein increases. The results also indicate the probability of the presence of unsaturated lipids and the absence of free aldehydes in the pollen wall and Ubisch bodies.     

OCCURRENCE OF TRI-LAMELLAR BODIES IN ISOLATES OF NOSTOC (CYANOPHYCEAE)1

Tri-lamellar bodies were observed in eight of 29 isolates of Nostoc examined. They appeared identical to the previously described bodies in various species of Anabaena. The bodies consist of three discoid lamellae each ca. 0.3 μm diam and 8 nm thick. The outer lamella (closest to the plasma membrane) is separated from the middle lamella by a 12 nm space whereas the middle and inner lamellae are ca. 8 nm apart. Osmiophilic striations 3 nm wide were generally observed running between the lamellae. Osmiophilic β granules were usually associated with the inner lamella. The bodies were most always located close to the plasma membrane along the longitudinal wall near the junction of the cross and longitudinal walls. In three isolates the bodies located near the cross walls were associated with gas vesicles and possessed a slightly different morphology. These tri-lamellar bodies consisted of three discoid lamellae, each ca. 2 nm thick, ca. 25 nm apart with electron dense material between the inner and middle lamellae. Pores 20 nm diam and ca. 60 nm apart were observed in layer 2 of the cell wall adjacent to the tri-lamellar bodies. These wall pores were also observed in isolates lacking tri-lamellar bodies.     

鹅掌楸属植物的多糖壁前体和花粉管的生长

本文观察描述了中国鹅掌楸（Ｌｉｒｉｏｄｅｎｄｒｏｎｃｈｉｎｅｎｓｅ）和北美鹅掌楸（Ｌ．ｔｕｌｉｐｉｆｅｒａ）花粉在异已柱头萌发和花粉管生长期间多糖壁前体的发生、形态结构和生理功能．１、多糖壁前体在形态上有Ｐ－粒子（Ｐｏｌｙｓａｃｃｈａｒｉｄｅｐａｒｔｉｃｌｅｓ）,被膜小泡（ｃｏａｔｅｄｖｅｓｉｃｌｅ）和小泡（ｖｅｓｉｃｌｅ）三种。２、Ｐ－粒子于单核花粉期已经发生,至花粉管延伸期为发生高峰。多糖壁前体是在高尔基体,内质网和线粒体的相继、连续作用下,由淀粉质体、蛋白体和脂滴降解形成．３、Ｐ－粒子的形态随不同发育时期而变化,早期为成群的电子透明小泡,或为蛋白质束缚的挤压成多面体形,后期为内含颗粒或微纤丝的无被膜粒子或具刺被膜粒子。４、Ｐ－粒子移至管端．或融合或单个通过周质内质网（ＣＥＲ）,释放内容物参与管端壁的形成,被膜小池和小泡移至花粉管次顶端区向质膜外分泌,参与花粉管壁内层的形成,或移至管端,提供膜片。最后讨论了亲和性与超微结构特征的关系．     

Killer toxin secretion through the cell wall of the yeastPichia anomala

A secreted killer toxin was detected through the cell wall ofPichia anomala cells by ultrastructural immunodetection with a specific monoclonal antibody (MAb KT4). MAb KT4 was successively detected by colloidal gold labeled streptavidin and biotinylated anti-mouse F(ab')₂ antibodies. The antigenic determinants of the toxin were localized throughout the cytoplasm and the cell wall of killer yeast cells. The Lowicryl K4M-immunogold method gave very satisfactory results and showed that the killer toxin was somewhat concentrated in the yeast cell wall layers before being exported into the medium. In agreement with previous reports, the binding of MAb KT4 suggested that theP. anomala killer toxin secretion did not result from a homogeneous diffusion across the yeast cell wall.Abbreviations G15 gold particles of 15 nm - IEM immunoelectron microscopy - IFA immunofluorescence assay - MAb monoclonal antibody - PBS phosphate buffered saline - SAM/F(ab)₂ sheep antibodies anti-mouse F(ab)₂ - SBB Sabouraud buffered broth     

Biomimetic particles for isolation and reconstitution of receptor function

Biomimetic particles supporting lipid bilayers are becoming increasingly important to isolate and reconstitute protein function. Cholera toxin (CT) from Vibrio cholerae, an 87-kDa AB₅ hexameric protein, and its receptor, the monosialoganglioside GM₁, a cell membrane glycolipid, self-assembled on phosphatidylcholine (PC) bilayer-covered silica particles at 1 CT/5 GM₁ molar ratio in perfect agreement with literature. This receptor-lig-and recognition represented a proof-of-concept that receptors in general can be isolated and their function reconstituted using biomimetic particles, i.e., bilayer-covered silica. After incubation of colloidal silica with small unilamellar PC vesicles in saline solution, pH 7.4, PC adsorption isotherms on silica from inorganic phosphorus analysis showed a high PC affinity for silica with maximal PC adsorption at bilayer deposition. At 0.3 mM PC, fluorescence of pyrene-labeled GM₁ showed that GM₁ incorporation in biomimetic particles increased as a function of particles concentration. At 1 mg/mL silica, receptor incorporation increased to a maximum of 40% at 0.2–0.3 mM PC and then decreased as a function of PC concentration. At 5 μM GM₁, 0.3 mM PC, and 1 mg/mL silica, CT binding increased as a function of CT concentration with a plateau at 2 mg bound CT/m² silica, which corresponded to the 5 GM₁/1 CT molar proportion and showed successful reconstitution of receptor-ligand interaction.