Disulphide Groups Research Articles

Physicochemical, volatile, amino acid, and sensory profiles of instant noodles incorporated with salted duck egg white from various salting durations

The physicochemical, volatile, amino acid, and sensory profiles of salted duck egg white (SDEW) incorporated in instant noodles were studied. There were nine instant noodle samples tested in the present work namely C1: wheat flour; WF; C2: WF ± non-salted duck egg white; T1: WF ± SDEW - 0 d; T2: WF ± SDEW - 5 d; T3: WF ± SDEW - 10 d; T4: WF ± SDEW - 15 d; T5: WF ± SDEW - 20 d; T6: WF ± SDEW - 25 d; and T7: WF ± SDEW - 30 d. The colour coordinates of lightness and yellowness continuously decreased from C2 to T7 (p < 0.05). The pH of C1 was the lowest. The cooking yield and optimum cooking time were highest for T7 (p < 0.05). Similarly, the hardness, firmness, chewiness, tensile strength, and elasticity were higher for SDEW-added noodles (p < 0.05). Conversely, the stickiness decreased but remained high in SDEW-added noodles. The free sulfhydryl (SH) and disulphide (SS) groups were higher in duck egg white (DEW) than in SDEW-added noodles. DEW- and SDEW-added noodles showed a wide range of flavour compounds (p < 0.05). Furthermore, there were 19 amino acids detected in the noodles, and SDEW-added noodles showed more and wider variety of amino acids (p < 0.05). Sensory characteristics such as colour, roughness, stickiness, firmness, flavour, and overall liking were slightly higher for T5 than the other treatments.

Synthesis, Stability, and Anti-Tumour Activity of a New Category of "Stapled" Antisense Oligonucleotides with Stimuli-Responsive Feature.

The development of nucleic acid drugs with unique structures and mechanisms has stimulated great research interest. Herein, we report a general strategy to construct "stapled" structures of single-stranded antisense oligonucleotides (ASONs) with a stimuli-responsive feature. "Stapled" cyclic structures can be synthesized with reactive bifunctional handles that react with thiol groups of phosphorothioate (PS)-modified ASONs, and can be alternatively adjusted depending on the desired PS sites in the ASON strand. The disulphide group in the stapled handle can be cleaved in the reducing microenvironment of tumour cells. Thus, "stapled" ASONs may be transformed back to a linear conformation to facilitate binding to target mRNAs. Stapling conferred protection against degradation, and enhanced anti-tumour activity compared to linear counterparts. This study provides a new, effective, and convenient strategy for designing ASONs with "stapled" structures, and also adds a further contribution to facilitate the stability and biological efficacy of novel nucleic acid-based therapeutics.

Brief descriptions of the principles of prominent methods used to study the penetration of materials into human hair and a review of examples of their use.

Consumers are attracted to the latest fashion trends and different looks. This drives the search for novel hair treatments. Some chemicals present in hair treatment products can penetrate the hair shaft. These materials can either nourish or injure the hair cortex. Different techniques have been used to investigate the mechanism of molecule penetration and the conditions under which penetration occurs. This article reviews the techniques applied for this purpose. Various microscopy techniques are used to capture clear and colourful images to determine the diffusion pathways and the exact location of the molecules under study. However, the laborious sample preparation often leads to sample destruction since cross-sectioning is often required. While various other techniques have been successfully used for investigating the penetration methods, most of these require different amounts of work to be put in for sample preparation and instrumentation. Several spectroscopic techniques have been used to study the penetration of the molecules because of the high levels of accuracy and the quick response time of these techniques. Moreover, the samples are not damaged during the investigation.

Effects of malondialdehyde‐induced protein oxidation on the structural characteristics of rice protein

SummaryMalondialdehyde (MDA) was selected to represent a secondary by‐product of lipid peroxidation during rice ageing. This study aimed to investigate the effects of MDA modification on the structural characteristics of rice protein. The results showed that as MDA concentration increased, rice protein carbonyl and disulphide groups increased, but sulphydryl content decreased. The blue shift of maximum fluorescence peak, the decrease of rice protein intrinsic fluorescence intensity and the reduction of surface hydrophobicity indicated the formation of protein aggregates caused by MDA oxidative modification. The results of molecular weight distribution and particle size distribution showed that MDA modification resulted in the formation of soluble protein aggregates, and the decrease of rice protein solubility indicated that insoluble protein aggregates were formed. Results of protein electrophoresis showed that MDA modification contributed to rice protein aggregation via non‐disulphide covalent bonds. The results showed that rice protein gradually aggregated with increasing MDA concentration.

Superior flame retardancy of cotton by synergetic effect of cellulose-derived nano-graphene oxide carbon dots and disulphide-containing polyamidoamines

Linear polyamidoamines containing disulphide groups (SS-PAAs) were prepared by polyaddition of L-cystine with 2,2-bisacrylamidoacetic acid (B-CYSS), N,N′-methylenebisacrylamide (M-CYSS) and 1,4-bisacryloylpiperazine (BP-CYSS). They were evaluated as flame retardants for cotton, alone or with cellulose-derived nano-graphene oxide (nGO) carbon dots, to assess whether, due to their potential as radical scavengers, the latter would improve the already good performance of SS-PAAs. In vertical flame spread tests (VFST), cotton treated with 1% nGO burned as quickly as cotton, whereas B-CYSS, M-CYSS and BP-CYSS extinguished the flame at add-ons ≥ 12, 16 and 20%, respectively. Probably, the gaseous products of SS-PAA thermal degradation quenched the radicals involved in oxidation. Cotton treated with 8, 12 and 15%, respectively, of B-CYSS, M-CYSS and BP-CYSS burned completely, but further addition of 1% nGO either inhibited ignition or shortly extinguished the flame, demonstrating synergism between the two components. Synergism was confirmed by assessing the synergism effectiveness parameter for the residual mass fraction (RMF) and by comparing the calculated and experimental TG curves in air for the cotton/SS-PAA-nGO systems. In cone calorimetry tests, the presence of nGO did not improve the already good performances of SS-PAAs, supporting the hypothesis that the action of both takes place in the gas phase.

Thiol-disulphide Homeostasis in Essential Thrombocythemia Patients.

SummaryBackgroundThis study aimed to show the status of thioldisulphide homeostasis in essential thrombocytosis patients, which is known to play a role in platelet function.MethodsThe study included 27 ET patients and a control group of 36 healthy subjects. Serum total (–SH + –S–S–) and native (–SH) thiol levels were measured in all subjects using an automatic method.ResultsAge and gender distribution were similar in both groups. Compared with the control group, in the ET group, there were increased native thiol and total thiol levels (p = 0.001, p = 0.046). There was no correlation between thiol, total thiol and disulphide ratios with Jak2 mutation, hemorrhage and thrombosis. A positive correlation was determined between thrombosis and thiol disulphide homeostasis (p = 0.058). The study results showed that thiol-disulphide homeostasis shifted to the proliferative side in ET, in which ineffective erythropoiesis was predominant. It is also known that platelets are more active in ET cases and thiol disulphide balance is important in platelet function.ConclusionsThis result suggests that thrombotic complications may be reduced if the formation is achieved of mechanisms (oxidation mechanisms) that will trigger the increase of disulphide groups. However, more extensive research is needed on this subject.

SYNTHESIS AND CHARACTERIZATION OF HYDROXYPROPYL CELLULOSE-CYSTEAMINE CONJUGATE AS A NOVEL CATIONIC THIOMER WITH LIPOPHILIC PROPERTIES

Objective: Thiomers have been known as polymer with mucoadhesive properties. The aim of this study was to synthesize the mucoadhesive potential of hydroxypropyl cellulose-cysteamine conjugate (HPC-cysteamine).Methods: The parent polymer HPC was chemically modified by introducing sulphydryl bearing compound using reductive amination. HPC-cysteamine conjugates were prepared at reaction pH value of 5. The reaction was stabilized by the addition of cyanoborohydride. Afterwards, the conjugate was evaluated for optimum free thiol group, swelling behavior, viscosity and mucoadhesive properties.Results: The conjugates showed maximum thiol incorporation on HPC of 1063.03±64.27 µmol/g. The disulphide groups content was 278.71±32.14 μmol/g. Mucoadhesion studies revealed that mucoadhesion of HPC-cysteamine demonstrated 26 h. The swelling behaviour of HPC-cysteamine tablets increased within the time period of study. The viscosity of HPC-cysteamine was higher than that of unmodified HPC. The thermal profile of HPC-cysteamine and unmodified HPC analyzed by differential scanning calorimetry (DSC) displayed a different enthalpy (ΔH) value.Conclusion: HPC-cysteamine conjugate renders better properties which might be more beneficial for drug delivery system compared to unmodified HPC.

A Raman spectroscopic investigation of the mechanism of the reduction in hair with thioglycerol and the accompanying disulphide conformational changes.

The objective of our research was to investigate the reduction mechanism of thioglycerol (TG) on hair keratin fibres. The structure of cross-sections at various depths of virgin white human hair resulting from the permanent waving process with TG was directly analysed at the molecular level using Raman spectroscopy. Also, the penetration of TG for the cross-sectional samples dyed with methylene blue was observed by optical microscopy. The gauche-gauche-gauche (GGG) and gauche-gauche-trans (GGT) conformations of disulphide (-SS-) groups remarkably decreased, while the trans-gauche-trans (TGT) conformation increased by performing the reduction process with TG. In addition, the disconnected -SS- content at various depths of the hair sample reduced with TG adjusted to pH 9.0 with ammonia solution was clearly increased compared with that of the hair sample reduced with TG adjusted to pH 9.0 with monoethanolamine. In the case of adjusting to pH 9.0 with ammonia solution, the tensile strength of the waved hair treated with TG was strong compared with that of the waved hair treated with thioglycolic acid (TGA), but the waving efficiency of the waved hair treated with TG was nevertheless higher than that of the waved hair treated with TGA. The author concluded that the waved virgin human hair treated with TG adjusted to pH 9.0 with ammonia solution was less damaged as compared with the waved hair treated with TGA, despite its good waving efficiency, as not only were the GGG and GGT conformations disconnected, but they were also changed to the TGT conformation by performing the reduction process with TG.

Interfacial properties of highly soluble crayfish protein derivatives

Abstract An analysis of the interfacial behaviour of two alternative protein derivatives with high solubility has been carried out at two different pH values (2 and 8). The protein derivatives (protein content higher than 50 wt.%) have a globular protein fraction mainly consisting of sarcoplasmic proteins (CFS); and a protein hydrolysate, (CFH), both obtained from crayfish surpluses. The physicochemical characterisation included protein solubility (higher than 80%) and surface charge as well as chemical analysis (elementary, sulfhydryl and disulphide groups). This was complemented with an interfacial characterization included measuring the surface pressure and surface dilatational measurements with a drop tensiometer, and interfacial shear rheology measurements performed using a double-wall-ring geometry. Whereas both types of protein derivative have significant interfacial activity (surface pressure between 20 and 40 mN/m), the difference in their behaviour is small In contrast, a strong influence of pH on the interfacial behaviour has been found for both soluble protein fractions. At pH 2, globular sarcoplasmic protein fraction yields lower surface pressures but highly viscoelastic interfaces, with 2D gel-like behaviour. At pH 8, on the other hand, CF proteins form quite rigid and more brittle interfaces, being resistant to dilatational deformations and showing high sensitivity to shear.

Immunocytochemical localization of sulfhydryl oxidase in mammalian epidermis suggests that the enzyme cross-links keratins in the granular and transitional corneous layers

The epidermis of representative mammalian species including humans has been examined for the presence of sulfhydryl oxidase, an enzyme likely involved in the oxidation of corneous proteins containing sulfhydryl groups in the epidermis. A database search indicates that the enzyme shares common sequences in numerous mammalian species so that an antibody against the human sulfhydryl oxidase 2 has been utilized on other species. The immunofluorescent study on the epidermis of the platypus (monotreme), red kangaroo (marsupials), hamster and human (placentals) reveals a prevalent labelling in the granular, transitional and lowermost part of the stratum corneous layer. The detailed ultrastructural immunogold study of the human epidermis reveals a diffuse and uneven labelling in the paler component of the composite keratohyalin granules or among keratin filaments of the transitional layer while the labelling disappears in the corneous layer. The study supports the hypothesis of the participation of the enzyme in the oxidative process that determines the formation of stable disulphide groups among keratins and other corneous proteins of the stratum corneum. This process gives rise to the resistant cell corneous envelope of keratinocytes in addition to the isopeptide bonds that derive from the catalytic action of epidermal transglutaminase on several corneous proteins.

Enzyme-directed pH-responsive exfoliation and dispersion of graphene and its decoration by gold nanoparticles for use as a hybrid catalyst

A non-destructive, safe and practical strategy to produce high quality graphene in high yield is urgently required, since this would pave the way for a wide range of applications of graphene in the future. Here we present a pH-responsive water-dispersible method for the exfoliation and functionalization of graphene by using lysozyme. The pH-responsive dispersion of graphene may be useful for the reversible assembly of multicomponent/multifunctional nanohybrid materials and nanoscale electronic devices. More importantly, composites can be easily constructed through the interactions between disulphide groups in lysozyme and gold nanoparticles (AuNPs). The resulting graphene-AuNPs composites show excellent catalytic activity towards reduction of o-nitroaniline by NaBH4. Since lysozyme is low cost and has antibacterial properties, and has been widely used in food preservation, medicine and the pharmaceutical industry, our approach may open a new scalable route for the manufacture of high-quality, nondestructive graphene for practical applications.

Synthesis and characterization of a cysteine xyloglucan conjugate as mucoadhesive polymer

The aim of this study was to improve the mucoadhesive potential of xyloglucan polymer by the covalent attachment of cysteine as thiol moiety. The parent polymer xyloglucan was chemically modified by introducing sulphydryl bearing compound L-cysteine HCl. Different batches of xyloglucan-cysteine conjugates were prepared at varying reaction pH (2-6) and evaluated for optimum thiol incorporation, disulphide group content, swelling behavior, rheological properties and mucoadhesive properties. The obtained conjugates characterized in vitro by quantification of immobilized thiol groups; showed maximum thiol incorporation on xyloglucan (7.67 ± 0.14 %) at pH 5. The disulphide group content was found maximum (2.83 ± 0.12) at pH 6. The water uptake at end of 4 h was 5.0 for xyloglucan and was found to decrease in thiolated derivatives with increase in thiolation. Mucoadhesion studies revealed that mucoadhesion of xyloglucan-cysteine conjugate increased more than twice compared to the unmodified polymer. The viscosity of thiomer was more than that of xyloglucan because of formation of disulphide bonds.

A phosphonium-type ionic liquid-modified Au electrode: a new platform for entrapping functional molecules on substrate surfaces

The liquid state of a bulky phosphonium-type ionic compound with a disulphide group was used to modify a Au substrate with effective dispersion. The substrate incorporates external compounds into the vacant space formed inside the ionic liquid regardless of the net charge of the compounds without any direct bonding.

Modifying thioredoxin expression in cereals leads to improved pre-harvest sprouting resistance and changes in other grain properties

Thioredoxins (Trxs) are widely distributed, small proteins that function in redox regulation in a broad spectrum of cellular reactions. Experimental work with barley, wheat and a legume (Medicago truncatula) has established thioredoxin h (Trx h) as a central regulatory protein in seeds, reducing disulphide (S–S) groups of diverse seed proteins, including storage proteins, enzymes and enzyme inhibitors. Trxs appear to be particularly important in plants, as a large number of genes are present compared to mammalian organisms. In Arabidopsis thaliana there are approximately 20 different genes for classical Trxs, and large Trx gene families have also been found in cereals, such as rice, barley, wheat and sorghum. Extensive evidence indicates that adding Trx, reduced nicotinamide adenine dinucleotide phosphate (NADPH) and NADP-thioredoxin reductase (NTR) to cereal flour or seed preparations reduces disulphide (S–S) linkages of storage proteins. The early in vitro studies have been complemented with transgenic barley seed, overexpressing Trx h in protein bodies of the barley endosperm, which showed accelerated germination and early or enhanced expression of associated enzymes, i.e., α-amylase and pullulanase. Overexpression of Trx h levels in wheat was subsequently shown to (1) enhance protein solubility and digestibility, (2) reduce allergenicity of wheat gliadins, and (3) improve dough quality from poor-quality wheat flour. Most recently, we have demonstrated that down-regulation in wheat of Trx h9, a unique thioredoxin, leads to a reduction in the incidence of pre-harvest sprouting, demonstrated in several varieties over multiple generations with field-grown material. Yield and starch content were increased while baking quality in the high-gluten variety remained unchanged. These observations led to the intriguing question of how changes in the endosperm are communicated to the embryo. Studies of Trx h9, a membrane-associated Trx h that can move from cell to cell, provide suggestive evidence for a role of Trx h9 in intercellular communication of redox state.

Synthesis and characterization of chitosan-homocysteine thiolactone as a mucoadhesive polymer

Abstract Two mucoadhesive thiolated polymers were synthesized by the covalent attachment of homocysteine thiolactone (HT) to chitosan and N , N , N -trimethyl-chitosan (TM-chitosan) at various chitosan:HT ratios. The amount of thiol and disulphide groups immobilized on the chitosan influenced the polymer's mucoadhesion positively and negatively, respectively, with the optimal chitosan:HT (w/w) ratio being found to be 1:0.1. The interaction between mucin and chitosan and its three derivatives was highest for the thiolated chitosan derivatives but was pH dependent. HT-chitosan and TM-HT-chitosan, with the thiol groups of 64.15 and 32.48 μmol/g, respectively, displayed a 3.67- and 6.33-fold stronger mucoadhesive property compared to that of the unmodified chitosan at pH 1.2, but these differences were only ∼1.7-fold at pH 6.4. The swelling properties of TM-HT-chitosan and HT-chitosan were higher than that of chitosan and TM-chitosan, attaining a swelling ratio of up to 240% and 140%, respectively, at pH 1.2 within 2 h.

Covalent chloramine inhibitors of blood platelet functions: Computational indices for their reactivity and antiplatelet activity

The quantum mechanics computation of the reactivities of chloramine derivatives of amino acids and taurine has been accomplished. A pair of computational indices that reflect a predisposition of alpha amino acid chloramines to chemical decay have been revealed. One of the indices was the dihedral angle for the chain of four atoms: carbons at beta- and alpha-positions, carbon of the carboxyl group, and carbonyl oxygen. The second index was the sum of partial charges for three or two carbon atoms in the chain. The amino acid chloramines with high values of the indices showed enhanced stability. Partial charges for active chlorine in known chloramines having different structures have been computed. The charges correlate with the rate constants of the reaction between chloramines and the thiol group of reduced glutathione. New derivatives of taurine chloramines have been constructed via the introduction of different substituents into the chloramine part. Among them, the amidoderivatives had the greatest charges of active chlorine (0.19-0.23). It was found in the study of the reactions of N-acetyl-N-chlorotaurine and N-propyonyl-N-chlorotaurine with amino acids and peptides possessing the thiol, thioester, or disulphide groups that the amidoderivatives manifested the thiol chemoselectivity. N-Acetyl-N-chlorotaurine and N-propionyl-N-chlorotaurine suppress the aggregation activity of blood platelets under their activation by the agonists ADP and collagen. It is not excluded that the amidoderivatives studied prevent platelet aggregation by a modification of the critical thiol group in the purine receptor P2Y12.

Directed immobilization of reduced antibody fragments onto a novel SAM on gold for myoglobin impedance immunosensing

The successful construction of an immunosensor depends on having an effective procedure for immobilising the bio-recognition element to the transducer surface. In the present study, an amino-terminated 4-aminothiophenol (ATP) self-assembled monolayer (SAM) was modified with heterobifunctional crosslinker sulfosuccinimidyl 4-[N-maleimidomethyl] cyclohexane-1-carboxylate to couple reduced anti-myoglobin half-antibody fragments. The disulphide groups present in the hinge region of IgG molecules were selectively cleaved by 2-mercaptoethylamine to produce reduced half-antibody fragments with free sulphydryl groups. The maleimide terminated 4-ATP SAM modified surface was coupled to these reduced antibody fragments to produce highly oriented immobilization of the half-antibody via its Fc domain and to allow free access to the Fv bindings sites. This represents an improvement by comparison with biotin/avidin mediated IgG attachment which is essentially randomly oriented. Functional immunosensors were able to detect myoglobin in both phosphate buffered saline and whole serum over the range of concentrations from 10 − 13 M to 10 − 6 M, and order of magnitude better than avidin/biotin linked immunosensors. In addition, atomic force microscopy (AFM) was carried out to elucidate the nanotopology of the immunosensor surface at different stages of fabrication; the images demonstrate that half antibodies bind as described and show structural changes on subsequent antigen binding.

Glyconjugates in epidermal, branchial and digestive mucous cells and gastric glands of gilthead sea bream, Sparus aurata, Senegal sole, Solea senegalensis and Siberian sturgeon, Acipenser baeri development.

Epidermal, branchial and digestive mucous cells, and the gastric glands of larvae/postlarvae (from hatching until 45 days posthatching) of three fish species (two teleostean and a chondrostean) were investigated using conventional histochemical methods (periodic acid schiff -PAS-, diastase-PAS; alcian blue pH 0.5, 1 and 2.5) in order to distinguish neutral and acidic (carboxylated and sulphated) glycoconjugates, as well as bromophenol blue reaction for identification of proteins. Additionally, the presence and distribution of sugar residues in the oligosaccharide side chains of glycoconjugates were investigated using horseradish peroxidase (HPR)-conjugated lectins (Con A, DBA, WGA and UEA-I). Most mucous cells (digestive, epidermal and branchial) of Siberian sturgeon, Acipenser baeri, sea bream, Sparus aurata and Senegal sole, Solea senegalensis larvae were PAS- and alcian blue- (pH 2.5 and 0.5) positive, with small variations between organs/tissues and species. Bromophenol blue reaction (general proteins) was positive in a minority of the mucous cells, usually in those cells which were PAS-negative. Proteins rich in sulphydryl (-SH) and/or disulphide (-S-S-) groups related with the glycoprotein nature of the glycoconjugates present in mucous cells were also observed. Epidermal, branchial and digestive mucous cells of all studied larvae did not contain glycogen or lipids. Con A lectin staining was negative in all mucous cells types of sea bream and sole, but oesophageal mucous cell of sturgeon were reactive to different lectin reactions, suggesting the presence of mannose -Man- and/or glucose -Glc-, L-fucose -Fuc- ; N-acetyl-D-galactosamine -GalNAc-, as well as N-acetyl-D-glucosamine- GlcNAc - and/or sialic acid -NANA- residues. Digestive mucous cells of all studied larvae were positive to WGA and DBA lectins. Epidermal and branchial mucous cells of sea bream and sole were Con A, DBA and UEA-I unreactive. However, mucous cells of sturgeon larvae were stained with UEA-I lectin. Gastric glands appear very early in sturgeon stomach larvae development (between 5-6 days posthatching) but rather late (around 40 days) during the ontogeny of sole and sea bream larvae. These glands contain neutral glycoproteins with Man and/or Glc, Fuc, GlcNAc- and/or sialic acid and rich in GalNAc- sugar residues, as well as proteins moderately rich in arginine, and others particularly rich in tyrosine and tryptophan.

Vibrational and electronic optical activity of the chiral disulphide group: Implications for disulphide bridge conformation

Using dihydrogendisulphide (H(2)S(2)), dimethyl- ((CH(3))(2)S(2)), and diethyldisulphide ((CH(3)CH(2))(2)S(2))as model molecules, theoretical ECD, VCD, and ROA spectra of nonplanar disulphides were calculated by DFT methods. Most of the calculated electronic and vibrational chiroptical features suffer an equivocal relation between calculatedsigns of ECD, VCD, or ROA and the sense of disulphide nonplanarity as noted earlier for low-lying ECD bands. This is a consequence of local C(2) symmetry of a disulphide group causing most electronic and vibrational transitions to occur as pairs falling to alternative A, B symmetry species, which become degenerate and switch their succession (and consequently the observed chiroptical sign pattern) at the energetically most favorable perpendicular conformation. According to present calculations, the key to resolving this ambiguity may involve the S-S stretching vibrational mode at approximately 500 cm(-1). The relation of signs of the relevant VCD and ROA features to sense of disulphide chirality seems simpler and less ambiguous. The right-handed arrangement of the S-S group (0 < chi(S-S) < 180 degrees) results in mostly negative VCD signals. Although relation to ROA still suffers some ambiguity, it gets clearer along the series H(2)S(2)-(CH(3))(2)S(2)-(CH(3)CH(2))(2)S(2). ROA is also attractive for the analysis of disulphide-containing peptides and proteins, because applying it to aqueous solutions is not problematic.

New reactive polymer for protein immobilisation on sensor surfaces

Immobilisation of biorecognition elements on transducer surfaces is a key step in the development of biosensors. The immobilisation needs to be fast, cheap and most importantly should not affect the biorecognition activity of the immobilised receptor. A novel protocol for the covalent immobilisation of biomolecules containing primary amines using an inexpensive and simple polymer is presented. This tri-dimensional (3D) network leads to a random immobilisation of antibodies on the polymer and ensures the availability of a high percentage of antibody binding sites. The reactivity of the polymer is based on the reaction between primary amines and thioacetal groups included in the polymer network. These functional groups (thioacetal) do not need any further activation in order to react with proteins, making it attractive for sensor fabrication. The novel polymer also contains thiol derivative groups (disulphide groups or thioethers) that promote self-assembling on a metal transducer surface. For demonstration purposes the polymer was immobilised on Au Biacore chips. The resulting polymer layer was characterised using contact angle meter, atomic force microscopy (AFM) and ellipsometry. A general protocol suitable for the immobilisation of bovine serum albumin (BSA), enzymes and antibodies such as polyclonal anti-microcystin-LR antibody and monoclonal anti-prostate specific antigen (anti-PSA) antibody was then optimised. The affinity characteristics of developed immunosensors were investigated in reaction with microcystin-LR, and PSA. The calculated detection limit for analytes depended on the properties of antibodies. The detection limit for microcystin-LR was 10 ng mL −1 and for PSA 0.01 ng mL −1. The non-specific binding of analytes to synthesised polymers was very low. The polymer-coated chips were stored for up to 2 months without any noticeable deterioration in their ability to react with proteins. These findings make this new polymer very promising for the development of low-cost, easy to prepare and sensitive biosensors.