Structure Of Bovine Serum Albumin Research Articles

A shift of the prooxidant-antioxidant balance in the bodies of laboratory animals at five-fold increased deuterium content in drinking diet

This paper presents the results of the study of the effect of water with deuterium content of 750 ppm, used for simulation of the isotopic composition of water in ice caps at the poles of Mars, on oxidative processes in the liver tissue and blood of laboratory animals. It was found that prolonged consumption of deuterium-enriched water contributed to an increase in the deuterium content in blood plasma up to 487 ppm. As a result, increased antioxidant activity in the liver tissues and blood plasma was observed. In addition, the effect of a medium that contains 487 ppm of deuterium on the secondary structure of bovine serum albumin was also investigated in a model experiment. A decrease in intensity of circular dichroism and intrinsic tryptophan fluorescence spectra was found. This indicates that there are conformational changes in the structure of this protein at a time when the content of deuterium increases in the incubation medium. The results of our research point to the need to explore further the effect of drinking diet with the increased deuterium to (from 700 to 1000 ppm) on living systems, to explain the possibility for life on Mars.

Study of the Binding of Cuminaldehyde with Bovine Serum Albumin by Spectroscopic and Molecular Modeling Methods

Here, we investigated the interaction of cuminaldehyde with a model carrier protein, bovine serum albumin (BSA). The formation of the BSA–cuminaldehyde complex was confirmed through ultraviolet–visible (UV–Vis) spectroscopy and further proven by detailed intrinsic fluorescence spectroscopic measurements. As observed, cuminaldehyde quenched the intrinsic tryptophanyl fluorescence of BSA. The fluorescence data, before the analyses, were corrected for the inner filter effect (IFE) because of the significant absorption of cuminaldehyde at the excitation wavelength that was employed in the measurements. The typical Stern–Volmer plots were slightly nonlinear; they exhibited negative deviation toward the x-axis, a typical phenomenon that is observed with proteins possessing more than one tryptophan residue. Thus, the modified Stern–Volmer equation was employed to analyze the data. The analyzed data revealed that the interaction of cuminaldehyde with BSA proceeded via a static quenching mechanism and that there was a fair 1 : 1 binding between them. The interaction was strengthened by hydrophobic forces and hydrogen bonding. A lowered concentration of cuminaldehyde did not affect the secondary structure of BSA, although an increased one partially exposed the protein by decreasing its α-helical contents. The molecular dockings and simulations of BSA and cuminaldehyde further confirmed the formation of the stable BSA–cuminaldehyde complex. The in silico results also revealed that the contributions of the hydrophobic interaction and hydrogen bonding were the driving forces that imparted the stability.

Study on the Interaction Mechanism of Theaflavin with Whey Protein: Multi-Spectroscopy Analysis and Molecular Docking.

The interaction mechanism of whey proteins with theaflavin (TF1) in black tea was analyzed using multi-spectroscopy analysis and molecular docking simulations. The influence of TF1 on the structure of bovine serum albumin (BSA), β-lactoglobulin (β-Lg), and α-lactoalbumin (α-La) was examined in this work using the interaction of TF1 with these proteins. Fluorescence and ultraviolet-visible (UV-vis) absorption spectroscopy revealed that TF1 could interact with BSA, β-Lg and α-La through a static quenching mechanism. Furthermore, circular dichroism (CD) experiments revealed that TF1 altered the secondary structure of BSA, β-Lg and α-La. Molecular docking demonstrated that the interaction of TF1 with BSA/β-Lg/α-La was dominated by hydrogen bonding and hydrophobic interaction. The binding energies were -10.1 kcal mol-1, -8.4 kcal mol-1 and -10.4 kcal mol-1, respectively. The results provide a theoretical basis for investigating the mechanism of interaction between tea pigments and protein. Moreover, the findings offered technical support for the future development of functional foods that combine tea active ingredients with milk protein. Future research will focus on the effects of food processing methods and different food systems on the interaction between TF1 and whey protein, as well as the physicochemical stability, functional characteristics, and bioavailability of the complexes in vitro or in vivo.

Laser-Based Mid-Infrared Spectroscopy for Monitoring Temperature-Induced Denaturation of Bovine Serum Albumin and De-/Stabilization Effects of Sugars.

Stability of high-concentration protein formulations is considered a major challenge in current biopharmaceutical development. In this work, we introduce laser-based mid-infrared (IR) spectroscopy as a versatile technique to study the effect of protein concentration and presence of sugars on the thermal denaturation of the model protein bovine serum albumin (BSA). Many analytical techniques struggle to characterize the complex structural transition that occurs during protein denaturation. To this end, a commercially available laser-based mid-IR spectrometer equipped with a customized flow cell was employed to record IR spectra of BSA in the temperature range of 25-85 °C. The temperature perturbation induces a conformational change from a native α-helical to an intermolecular β-sheet secondary structure in BSA. Systematic investigation of the concentration dependence of the α-β transition temperature between 30 and 90 mg mL-1 shows a trend of decreasing denaturation temperatures at higher BSA concentrations. In-depth chemometric analysis by a multivariate curve resolution-alternating least squares (MCR-ALS) analysis of the spectra, suggested the formation of not one but two intermediates in the denaturation of BSA. Subsequently, the impact of sugars on denaturation temperatures was investigated, revealing both stabilizing (trehalose, sucrose, and mannose) and destabilizing (sucralose) effects, illustrating the applicability of this method as an investigative tool for stabilizers. These results highlight the potential and versatility of laser-based IR spectroscopy for analysis of protein stability at high concentrations and varying conditions.

Interrogating Encapsulated Protein Structure within Metal–Organic Frameworks at Elevated Temperature

Encapsulating biomacromolecules within metal-organic frameworks (MOFs) can confer thermostability to entrapped guests. It has been hypothesized that the confinement of guest molecules within a rigid MOF scaffold results in heightened stability of the guests, but no direct evidence of this mechanism has been shown. Here, we present a novel analytical method using small-angle X-ray scattering (SAXS) to solve the structure of bovine serum albumin (BSA) while encapsulated within two zeolitic imidazolate frameworks (ZIF-67 and ZIF-8). Our approach comprises subtracting the scaled SAXS spectrum of the ZIF from that of the biocomposite BSA@ZIF to determine the radius of gyration of encapsulated BSA through Guinier, Kratky, and pair distance distribution function analyses. While native BSA exposed to 70 °C became denatured, in situ SAXS analysis showed that encapsulated BSA retained its size and folded state at 70 °C when encapsulated within a ZIF scaffold, suggesting that entrapment within MOF cavities inhibited protein unfolding and thus denaturation. This method of SAXS analysis not only provides insight into biomolecular stabilization in MOFs but may also offer a new approach to study the structure of other conformationally labile molecules in rigid matrices.

Conformational changes and location of BSA upon immobilization on zeolitic imidazolate frameworks

The location and the conformational changes of proteins/enzymes immobilized within Metal Organic Frameworks (MOFs) are still poorly investigated and understood. Bovine serum albumin (BSA), used as a model protein, was immobilized within two different zeolitic imidazolate frameworks (ZIF-zni and ZIF-8). Pristine ZIFs and BSA@ZIFs were characterized by X-ray diffraction, small-angle X-ray scattering, scanning electron microscopy, confocal laser scanning microscopy, thermogravimetric analysis, micro-FTIR and confocal Raman spectroscopy to characterize MOFs structure and the protein location in the materials. Moreover, the secondary structure and conformation changes of BSA after immobilization on both ZIFs were studied with FTIR. BSA is located both in the inner and on the outer surface of MOFs, forming domains that span from the micro- to the nanoscale. BSA crystallinity (β-sheets + α-helices) increases up to 25 % and 40 % due to immobilization within ZIF-zni and ZIF-8, respectively, with a consequent reduction of β-turns.

Investigating the Protective Role of Biochaga Drug on Structural Changes of Bovine Serum Albumin in the Presence of Methyl tert-butyl Ether.

The health benefits of natural products have a long history. Chaga (Inonotus obliques) is used in traditional medicine and is an essential antioxidant for protecting the body from oxidants. Reactive oxygen species (ROS) are produced routinely due to metabolic processes. However, environmental pollution factors such as methyl tert-butyl ether (MTBE) can increase oxidative stress in the human body. MTBE is widely used as a fuel oxygenator that can harm health. The widespread use of MTBE has posed significant threats to the environment by polluting environmental resources, including groundwater. This compound can accumulate in the bloodstream by inhaling polluted air, with a strong affinity for blood proteins. The primary mechanism of MTBE's harmful effects is ROS production. The use of antioxidants may help reduce MTBE oxidation conditions. The present study proposes that biochaga, as an antioxidant, can reduce MTBE damage in the bovine serum albumin (BSA) structure. This study investigated the role of different concentrations of biochaga in the structural change of BSA in the presence of MTBE by biophysical methods such as UV-Vis, fluorescence, FTIR spectroscopy, DPPH radical inhibition method, aggregation test, and molecular docking. Research at the molecular level is critical to investigate the structural change of proteins by MTBE and the protective effect of the ideal dose (2.5µg/ml) of biochaga. the results of spectroscopic examinations showed that the concentration of 2.5µg/ml of biochaga has the least destructive effect on the structure of BSA in the presence and absence of MTBE, and it can play as an antioxidant.

Synthesis and Characterization of Alpinia calcarata Loaded Nanoparticles to Control Hyperglycemia

Bovine Serum Albumin (BSA) nanoparticles loaded with the bioactive compounds of A. calcarata, which is known to exert its antidiabetic activity through the inhibition of pancreatic enzymes, are a good form of an antidiabetic nutraceutical as they have reduced side effects, protection of active compounds from environmental agents, specific delivery to target sites and prolonged shelf-life. The objective of the present study was to synthesize and characterize A. calcarata loaded nanoparticles (ALNP) to be used as a powder form nutraceutical with higher antidiabetic activity. In this study an aqueous A. calcarata extract (4.00 mL) was added to BSA (20 mg/mL, 4.00 mL, pH 9) in the presence of citric acid as the cross-linking agent. The ALNP gave an IC50 value of 147 µg/mL, a glucose (5 mM) uptake percentage of 73.09% at a 0.5 mg/mL concentration, a solubility value of 64%, A. calcarata loading percentage of 6.66% and A. calcarata entrapment efficiency of 87.71%. They had a spherical morphology and uniform size with a particle size of 1030.70 nm, PDI of 0.199 and a zeta potential of 2.57 mV. The UV-Visible absorbance spectra and FT-IR spectra showed that citric acid had caused conformational changes in the protein structure of BSA and that the active compounds were successfully loaded into the synthesized nanoparticles which interacted with the protein matrix via covalent bonds. Therefore, it can be concluded that the synthesized nanoparticles have an antidiabetic effect and the antidiabetic activity of bioactive compounds of the aqueous A. calcarata extract become enhanced when loaded onto the nanocarriers.

Exploring the binding characteristics of bovine serum albumin with tyrosine kinase inhibitor entrectinib: Multi-spectral analysis and theoretical calculation

Entrectinib (ENB) is one of multi-target tyrosine kinase inhibitors, which is mainly used for treating neurotrophic tyrosine receptor kinase gene fusion positive solid tumors. The binding characteristics of ENB and bovine serum albumin (BSA) were studied by experiments and theoretical calculations. The steady-state fluorescence showed that ENB quenched the fluorescence of BSA through mixed quenching, and ENB was dominated by static quenching at low concentration. ENB and BSA had a moderate affinity, formed a complex with a stoichiometric ratio of 1:1 and the binding constant of about 105 M−1 at 298 K, and Förster non-radiative energy transfer occurs. According to the driving force competition experiment, thermodynamic parameter analysis and theoretical calculation, hydrogen bond, van der Waals force and hydrophobic force were the main factors affecting the stability of the ENB-BSA complex. Molecular docking and site markers competition showed that ENB spontaneously bound to the Site III of BSA so that ENB could make the skeleton of BSA loose, the spatial structure of BSA changed (α-helix decreased by 3.1%, random coil increased by 1.7%), and the microenvironment of Tyr and Trp residues changed. The existence of Co2+ metal ions can enhance the binding effect, thus prolonging the half-life of ENB in vivo, which may improve the efficacy of ENB, while Ca2+, Cu2+ and Mg2+ metal ions will reduce the efficacy of ENB.

Agarose native gel electrophoresis analysis of thermal aggregation controlled by Hofmeister series

The effects of salting-in and salting-out salts defined by Hofmeister series on the solution state of bovine serum albumin (BSA) in 50 mM Tris-HCl buffer at pH 7.4 before and after thermal unfolding at 80 °C for 5 min were examined using agarose native gel electrophoresis and mass photometry. Gel electrophoresis showed that salting-in MgCl2, CaCl2 and NaSCN resulted in formation of intermediate structures of BSA upon heating on native gel, while heating in buffer alone resulted in aggregated bands. Mass photometry showed large loss of monomer and oligomers when heated in this buffer, but retaining these structures in the presence of 1 M MgCl2 and NaSCN. To our surprise, salting-out MgSO4 also showed a similar effect on gel electrophoresis and mass photometry. Salting-out NaCl and (NH4)2SO4 resulted in smearing and aggregated bands, which were supported by mass photometry. Aggregation-suppressive ArgHCl also showed oligomer aggregates upon gel electrophoresis and mass photometry.

How ractopamine binds to bovine serum albumin at the drug site 1

ABSTRACT Ractopamine (RAC) is a common -agonist often used as a feed additive to improve muscle mass in farm animals. However, RAC has been banned in several countries due to its toxicity. To date, no clear evidence shows pharmacological and poisonous adverse effect of RAC in farm animals. In beef cattle, although RAC can be carried by bovine serum albumin (BSA) at drug site I, its effect on BSA structure and function remains unclear. Thus, in this work, Molecular Dynamics (MD) Simulations were employed to explore the binding interactions of RAC to BSA. Seemingly, RAC causes the high flexibility of domains I and III and importantly induces the large expansion of drug site II’s cavity which can interfere the drug-binding ability of drug site II. RAC binds to drug site I close to subdomain IIA, which is the same naproxen-binding site. Like naproxen, a polar moiety of RAC interacts with R194, R198 and W213. Our results reveal the RAC intrusion into the fatty acid site 6 (FA6) which implies the connection between drug site I and FA6 site. An insight into the RAC-BSA binding here can act as a base to better understand a drug distribution and bioavailability in cattle.

Biophysical study of cisplatin loaded albumin-gold nanoparticle and its interaction with glycans of gp60 receptor

The biophysical study provides a quantitative understanding of biomolecular interaction. The interaction of protein-nanoparticle has been critically examined using various biophysical and biochemical tools. The present investigation focussed on the biophysical characterization of anticancer drug cisplatin (CPT) with Bovine Serum Albumin (BSA) - Gold nanoparticles (GNP) conjugate; and BSA-CPT-GNP interaction with glycan sugars of glycoprotein receptor. Spectroscopic study (UV visible and fluorescence) showed strong binding of CPT loaded BSA with GNP. The binding between BSA-CPT-GNP and glycan sugars of gp60 receptor was estimated. Circular Dichroism (CD) spectroscopy study revealed weak alteration in the secondary structure of BSA upon CPT and GNP binding. Dynamic Light Scattering (DLS) data indicated the changes in the size of conjugates; zeta potential data showed the stability of conjugates. Biocompatible studies showed no toxicity to RBCs and chorioallantoic membrane (CAM). The mechanisms of interaction have been explored at the molecular and cellular levels. This investigation can be effectively extrapolated for in-vivo and in-vitro targeted drug delivery studies for cancer therapy.

Inhibitory effect of a Chinese quince seed peptide on protein glycation: A mechanism study

Non-enzymatic glycation can cause the formation and accumulation of advanced glycation end products (AGEs), and it poses great threats to human health. It is urgent to search for safe and efficient inhibitors to prevent reducing sugar induced protein glycation. In this study, we investigated the anti-glycation activity and mechanism of an identified peptide, Asparagine-Tyrosine-Arginine-Arginine-Glutamic acid (NYRRE) from Chinese quince seed protein hydrolysate, by multispectroscopy, confocal imaging, and computational molecular simulation. Firstly, it was found that NYRRE could scavenge hydroxyl radicals and chelate Fe2+. Besides, the NYRRE was effective in every stage of fructose induced bovine serum albumin (BSA) glycation. The NYRRE could reduce the formation of fructosamine, carbonyl compounds, glycoxidation products and β-amyloid structure. Meanwhile, NYRRE could protect thiol groups and stabilize the spatial conformation of BSA. The NYRRE presented strong inhibition in fluorescent AGEs, and 68.19% of total AGEs formation was prevented with NYRRE at 15 mmol/L. The results of molecular simulation indicated that NYRRE could insert into the hydrophobic pocket of BSA and interact with hot spots, including arginine and lysine residues. The mechanism of NYRRE inhibiting protein glycation could be due to its antioxidant activity, BSA structure stabilizing ability, and specific bond with glycation sites of BSA. These results provided a valuable reference for developing NYRRE as an efficient antiglycation agent in preventing glycation-mediated diseases.

INVESTIGATION ON THE INTERACTION OF β-SITOSTEROL AND LUTEOLIN-7-GLUCOSIDE BINDING TO BOVINE SERUM ALBUMIN

Objective: The study ondrug–protein interactions is an important field of interest because of the prospective of unraveling of drug action mechanisms and the possibility of designing novel medicines. Bovine serum albumin (BSA) has been studied extensively because of its structural homology with human serum albumin (HSA). The objective of the work was to study the interaction between β-sitosterol and Luteolin–7-glucoside with bovine serum albumin (BSA) investigated by molecular docking. Methods: Docking studies were carried out using a crystal structure of bovine serum albumin complexed with naproxen (pdb code-4OR0). Auto dock 4.2 was used to perform molecular docking. Ligands were found flexible during the docking process, and protein was kept rigid. Results: Molecular docking studies revealed that the β-sitosterol can bind in the large hydrophobic cavity of BSA, mainly by the hydrophobic interaction but also by hydrogen bond interactions between the hydroxyl (OH) group of β-sitosterol to SER 488 with hydrogen bond distance of 2.1Å. Luteolin-7-glucoside molecule interact by hydrophobic interaction with LYS 431, ARG 427, ALA 193 amino acids of Bovine Serum Albumin. The amino acids ARG 458, ARG 435, ARG 185 are involved in forming a hydrogen bond with hydroxyl oxygens, carbonyl carbon of Luteolin-7-glucoside with hydrogen bond distance of 2.4, 2.3 and 1.9 Å, respectively. Conclusion: Study indicated that hydrophobic and hydrogen bonding interactions were mostly responsible for albumin interaction. Further research of the pharmaceutical potential of plant molecules will be valuable for monitoring their biological functions.

Influences of protein-corona on stability and aggregation kinetics of Ti3C2Tx nanosheets in aquatic environment

Proteins existed in aquatic environments strongly influence the transport, fate of nanomaterials due to the formation of protein-corona surrounding nanomaterials. To date, how do proteins affect the aggregation behaviors of MXene, a new family of two-dimensional materials, in aquatic environment remains unknown. Here the aggregation kinetics of MXene Ti3C2Tx nanosheets in various electrolytes (NaCl, CaCl2 and Na2SO4) was investigated by time-resolved dynamic light scattering in absence or presence of bovine serum albumin (BSA). Results showed that BSA affected the aggregation of Ti3C2Tx in a concentration-dependent manner. Addition of 3 mg/L BSA decreased the critical coagulation concentrations (CCCs) of Ti3C2Tx about 1.6–2.1 times, showing obvious destabilization effect; while BSA greater than 30 mg/L created a high-protein environment covering Ti3C2Tx, producing high spatial repulsion and enhancing the dispersibility of Ti3C2Tx. Ca2+ ions have greater effect on the aggregation of Ti3C2Tx due to the larger surface charge and bridging effect. The interaction between Ti3C2Tx and BSA followed Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, and mainly attributed to hydrogen bonding and van der Waals forces, while positively charged lysine and arginine in BSA might attract onto Ti3C2Tx through electrostatic attraction. The interaction decreased the content of α-helix structure in BSA from 74.7% to 53.1%. Ti3C2Tx easily suffered from aggregation and their long-distance transport seemed impossible in synthetic or natural waters. The present findings provided new insights for understanding the transfer and fate of this nanomaterial in aquatic environments.

Spectroscopic studies on binding of ibuprofen and drotaverine with bovine serum albumin

The interaction between ibuprofen (analgesic) and drotaverine (smooth muscle relaxant) drugs with bovine serum albumin (BSA) was investigated using both experimental (UV–Vis, fluorescence, and circular dichroism spectroscopy) and theoretical (molecular mechanics) methods. Both drugs quench the intrinsic fluorescence of BSA through static processes. The binding constant of the BSA–drotaverine complex is found to be relatively higher than that of the BSA–ibuprofen complex. The binding distance between BSA and ibuprofen/drotaverine was calculated to be 1.7 and 3.1 nm, respectively. Both fluorescence and circular dichroism spectral studies confirmed conformational changes in the BSA upon binding with these drugs. From both displacement competition studies and molecular docking, it was found that drotaverine can displace ibuprofen at higher concentrations, but ibuprofen can bind to other sites on the BSA. Circular dichroism showed that drotaverine has a stabilizing effect on the secondary structure of BSA in the presence of ibuprofen, which on its own leads to an increase in the disordered fraction at high concentrations.These observations imply that concurrent administration of these two drugs can be effective as a combination therapy in the management of pain due to primary dysmenorrhea, even when the disease tends to gain resistance to the NSAIDs; their competition for the BSA binding sites should be taken into account.

Interaction thermodynamics investigation of bovine serum albumin with black phosphorus quantum dots via spectroscopic and molecular simulation techniques

In this paper, the binding interaction thermodynamics of black phosphorus quantum dots (BPQDs) with bovine serum albumin (BSA) was explored systematically and comprehensively to interpret the influence of BPQDs on both the conformational structure and the biological function of BSA. The results of a variety of spectroscopic strategies and molecular simulation technique revealed that the endogenous fluorescence of BSA was quenched by BPQDs spontaneously via the static quenching mechanism based on the main binding forces of van der Waals interaction and hydrogen bonds formation. BPQDs interacted strongly with the Sudlow's site I of BSA via stoichiometric ratio of 1:1 to construct the novel stable ground-state complex. The results of three-dimensional fluorescence spectrometry and circular dichroism spectroscopy showed that BPQDs reduced the prominent α-helix structure content and the thermal stability of BSA through concentration-dependent manner. These results not only disclose the binding interaction mechanism of BPQDs with BSA comprehensively but also illustrate the variation of the secondary structure of BSA after its association with BPQDs carefully. Such research paves the way for the targeted design of black phosphorus derivatives with excellent biocompatibility and the safety application of such nanoparticles in the clinic diagnosis and the effective therapy of serious diseases in human beings.

Bovine serum albumin functional graphene oxide membrane for effective chiral separation

An efficient chiral separation membrane was fabricated from bovine serum albumin (BSA) modified graphene oxide (GO), BSA was linked with GO through EDC/NHS coupling chemistry. This BSA modified membrane can successfully separate Phe racemate, and the excess enantiomer (ee) in osmotic solution was up to 96.1% under the optimal conditions. We found that the addition of BSA not only enlarged the spacing but also formed chiral channels in the membrane to selective transport of L-Phe, enabling the chiral membrane to have both high flux and high selectivity. Further, we confirmed that the microstructure of BSA plays an important role in the chiral separation performance of the membrane. When the helical structure and globular three-dimensional structure of BSA are unfolding due to temperature rise, the chiral separation performance of the membrane will be weakened or even disappear. Addition, molecular docking simulation experiments also proved the reliability of this conclusion.

Antiglycoxidative properties of amantadine – a systematic review and comprehensive in vitro study

An important drug used in the treatment of Parkinson’s disease is amantadine. We are the first to perform a comprehensive study based on various glycation and oxidation factors, determining the impact of amantadine on protein glycoxidation. Sugars (glucose, fructose, galactose) and aldehydes (glyoxal, methylglyoxal) were used as glycation agents, and chloramine T was used as an oxidant. Glycoxidation biomarkers in albumin treated with amantadine were generally not different from the control group (glycation/oxidation factors), indicating that the drug did not affect oxidation and glycation processes. Molecular docking analysis did not reveal strong binding sites of amantadine on the bovine serum albumin structure. Although amantadine poorly scavenged hydroxyl radical and hydrogen peroxide, it had significantly lower antioxidant and antiglycation effect than all protein oxidation and glycation inhibitors. In some cases, amantadine even demonstrated glycoxidant, proglycation, and prooxidant properties. In summary, amantadine exhibited weak antioxidant properties and a lack of antiglycation activity.

Development of various carbon nanoparticles and albumin complexes for potential theranostics applications

Carbon quantum dots (CQDs) are promising materials for many biomedical applications. However, their unique properties may be much enhanced by heteroatom doping and albumin decorating, which leads to improved functionality as reliable CQD-based simultaneous diagnosis and drug delivery systems, respectively. Therefore, in this study, three types of CQDs, with various doping conditions, namely pure carbon dot (CDs), N-doped CQD (NCDs), and S–N doped CQD (SNCDs), were functionalized over bovine serum albumin (BSA), a type of serum protein that is commonly used in drug delivery systems, and their binding was systematically optimized using the central composite design algorithm, by response surface methodology. Therefore three types of CQD-BSA complexes were obtained, namely CD-BSA, NCD-BSA, and SNCD-BSA. The statistical system was set to achieve the best results for both the absorbance of BSA, as well as the emission strength for each CQD-BSA complex. The structural changes of BSA have been investigated by the FTIR spectrum for various CQD-BSA complexes, indicating that the secondary structure and biological activity of BSA have not been influenced significantly, after incubation with different CQDs, except for a slight change in the case of SNCDs-BSA complex, inferring non-covalent interaction in some binding sites. The fluorescence intensity results also show that the formation of the complex did not reduce the emission of CQDs very much. Based on the results, the synthesized complexes can serve as suitable carriers for simultaneous drug delivery and diagnosis applications.