Insulin Degradation Research Articles

Insulin signaling in health and disease.

The molecular mechanisms of cellular insulin action have been the focus of much investigation since the discovery of the hormone 100 years ago. Insulin action is impaired in metabolic syndrome, a condition known as insulin resistance. The actions of the hormone are initiated by binding to its receptor on the surface of target cells. The receptor is an α2β2 heterodimer that binds to insulin with high affinity, resulting in the activation of its tyrosine kinase activity. Once activated, the receptor can phosphorylate a number of intracellular substrates that initiate discrete signaling pathways. The tyrosine phosphorylation of some substrates activates phosphatidylinositol-3-kinase (PI3K), which produces polyphosphoinositides that interact with protein kinases, leading to activation of the kinase Akt. Phosphorylation of Shc leads to activation of the Ras/MAP kinase pathway. Phosphorylation of SH2B2 and of Cbl initiates activation of G proteins such as TC10. Activation of Akt and other protein kinases produces phosphorylation of a variety of substrates, including transcription factors, GTPase-activating proteins, and other kinases that control key metabolic events. Among the cellular processes controlled by insulin are vesicle trafficking, activities of metabolic enzymes, transcriptional factors, and degradation of insulin itself. Together these complex processes are coordinated to ensure glucose homeostasis.

Evaluation of C-peptide and insulin resistance in nondiabetic patients with chronic kidney disease

IntroductionChronic kidney disease (CKD) is a pathophysiologic process with several etiologies, resulting in remarkable decrease in nephron number and function. Patients with CKD have reduced life span, and a considerable proportion of these individuals die owing to cardiovascular complications. In CKD, degradation of insulin in nonrenal tissues such as liver and muscle is impaired, and the half-life of insulin is prolonged, so a state of hyperinsulinemia with increased C-peptide levels occurs in patients with CKD.AimTo assess serum insulin and C-peptide along with homeostasis model assessment-insulin resistance (IR) in nondiabetic patients with CKD.Patients and methodsThe study included 70 nondiabetic patients with CKD and 20 controls. Fasting serum C-peptide and insulin were done by enzyme-linked immunosorbent assay technique, and IR was calculated using the homeostasis model assessment-IR formula.ResultsFasting serum levels of insulin and C-peptide were statistically significantly higher in nondiabetic patients with CKD compared with control individuals. Patients with stage 4 CKD had a statistically significant increase in fasting insulin levels compared with stage 3 patients, whereas there was no statistically significant difference between stage 5 and stage 4 patients. Fasting C-peptide levels show no statistically significant difference between the different stages of patients with CKD. IR levels were statistically significantly higher in the patient group compared with the controls. Patients with stage 4 CKD had statistically significantly higher levels of IR compared with stage 3 patients. There was no statistically significant difference between patients with stage 4 and stage 5 CKD.ConclusionThe study demonstrates an increase in the IR in nondiabetic patients with CKD.

The insulin-degrading enzyme as a link between insulin and neuropeptides metabolism

We have applied a recently developed HPLC-MS enzymatic assay to investigate the cryptic peptides generated by the action of the insulin-degrading enzyme (IDE) on some neuropeptides (NPs) involved in the development of tolerance and dependence to opioids. Particularly, the tested NPs are generated from the NPFF precursor (pro-NPFF (A)): NPFF (FLFQPQRF) and NPAF (AGEGLSSPFWSLAAPQRF). The results show that IDE is able to cleave NPFF and NPAF, generating specific cryptic peptides. As IDE is also responsible for the processing of many other peptides in the brain (amyloid beta protein among the others), we have also performed competitive degradation assays using mixtures of insulin and the above mentioned NPs. Data show that insulin is able to slow down the degradation of both NPs tested, whereas, surprisingly, NPAF is able to accelerate insulin degradation, hinting IDE as the possible link responsible of the mutual influence between insulin and NPs metabolism.

The Roles of Beclin 1 Expression in Gastric Cancer: A Marker for Carcinogenesis, Aggressive Behaviors and Favorable Prognosis, and a Target of Gene Therapy.

Beclin 1 is encoded by Becn1, and plays a role in tumorigenesis, neurodegeneration, apoptosis and autophagy. Here, the aggressive phenotypes and relevant proteins were examined after Beclin 1 expression was altered in gastric cancer cells. We also observed the effects of Beclin 1 on gastric carcinogenesis using Becn1 knockout mice. Finally, clinicopathological significances of Beclin 1 expression were analyzed using meta- and bioinformatics analyses. Becn1 overexpression was found to inhibit proliferation, glucose metabolism, migration and invasion of gastric cancer cells, whereas its knockdown caused the opposite effects. Beclin 1 suppressed the tumor growth by decreasing proliferation and increasing apoptosis. The heterozygous abrogation of Becn1 in gastric pit, parietal and chief cells could not cause any epithelial lesion. Beclin 1-mediated chemoresistance was closely linked to the autophagy, Bax underexpression, and the overexpression of Bcl-2, LRP1, MDR1, and ING5. Bioinformatics analysis showed higher Becn1 mRNA expression in intestinal- than diffuse-type carcinomas (P<0.05), and in male than female gastric cancer patients (P<0.05). Becn1 hyperexpression was positively associated with both overall and progression-free survival rates of the cancer patients (P<0.05). Meta-analysis showed that down-regulated Beclin 1 expression in gastric cancer was positively with lymph node metastasis, TNM staging, dedifferentiation and poor prognosis (P<0.05). Becn1-related signal pathways in gastric cancer included prostate, lung, renal, colorectal, endometrial and thyroid cancers, glioma, and leukemia, the metabolism of amino acid, lipid and sugar, and some signal pathways of insulin, MAPK, TRL, VEGF, JAK-STAT, chemokine, p53, lysosome, peroxidome and ubiquitin-mediated protein degradation (P<0.05). These suggested that Beclin 1 might be considered as a potential marker of gastric carcinogenesis, aggressiveness and prognostic prediction, and as a target of gene therapy in gastric cancer.

Abelmoschus esculentus subfractions attenuate A\u03b2 and tau by regulating DPP-4 and insulin resistance signals

BackgroundInsulin resistance could be associated with the development of Alzheimer disease (AD). The neuropathological hallmarks of AD are beta amyloid (Aβ) produced from sequential cleavage initiated by β-secretase and degraded by insulin degradation enzyme (IDE), as well as hyperphosphorylation of tau (p-tau). Insulin action involves the cascades of insulin receptor substrates (IRS) and phosphatidylinositol 3-kinase (PI3K), while phosphorylation of IRS-1 at ser307 (p-ser307IRS-1) hinders the response. Our previous report suggested dipeptidyl peptidase-4 (DPP-4) is crucial to insulin resistance, and the subfractions of Abelmoschus esculentus (AE), F1 and F2, attenuate the signaling. Here we aim to investigate whether AE works to reduce Aβ generation via regulating DPP4 and insulin resistance.MethodsThe subfractions F1 and F2 were prepared according to a succession of procedures. F1 was composed by quercetin glycosides and triterpene ester, and F2 contained a large amount of polysaccharides. The in vitro insulin resistance model was established by SK-N-MC cell line treated with palmitate. MTT was used to define the dose range, and thereby Western blot, ELISA, and the activity assay were used to detect the putative markers. One-way ANOVA was performed for the statistical analysis.ResultsTreatment of palmitate induced the level of p-ser307IRS-1. Both F1 and F2 effectively decrease p-ser307IRS-1, and recover the expression of p-PI3K. However, the expression of total IRS plunged with 25 μg/mL of F1, while descended steadily with 5 μg/mL of F2. As palmitate increased the levels of Aβ40 and Aβ42, both AE subfractions were effective to reduce Aβ generation of and β-secretase activity, but IDE was not altered in any treatment conditions. The expression of DPP4 was also accompanied with insulin resistance signals. Inhibition of DPP4 attenuated the activity of β-secretase and production of Aβ. Moreover, the present data revealed that both AE subfractions significantly decrease the level of p-Tau.ConclusionsIn conclusion, we demonstrated that AE would be a potential adjuvant to prevent insulin resistance and the associated pathogenesis of AD, and F2 seems more feasible to be developed.

Caveolin-1 (CAV-1) up regulation in metabolic syndrome: all roads leading to the same end.

Metabolic syndrome (MS) is a set of clinical conditions such as insulin resistance, hyperglycemia, systemic arterial hypertension (SAH), dyslipidemia, obesity and high abdominal circumference. Some of these clinical characteristics have been associated with caveolin-1, a caveolae structural protein, responsible for insulin activation, storage and degradation of cholesterol, and so on. Herein we assessed CAV-1 mRNA levels in MS patients comparing to healthy controls (HC) and according patients' clinical features. We included 87 patients in the study, 25 patients with MS, 30 patients with at least one clinical condition (diabetes, SAH, dyslipidemia, obesity and high abdominal circumference), 13 with two clinical conditions and 19 HC. CAV-1 mRNA levels from peripheral blood samples were assessed by Real Time qPCR using specific Taqman probe. The analysis was performed using ∆Cq method and the statistical tests Shapiro-Wilk, One-Way ANOVA and Mann-Whitney. We found CAV-1 increased mRNA levels in patients with MS (1.645 FC, p = 9.794 × 10-20) and even higher in patients with only one or two clinical conditions (2.215 FC, p = 1.215 × 10-32 and 1.716 FC, p = 4.197 × 10-05, respectively). When individual clinical conditions were observed, individuals with high abdominal circumference and obesity present a significantly up regulation when compared to HC (2.956 FC, p = 0.0004 and 3.643 FC, p = 0.002, respectively). This work indicates that CAV-1 gene expression from whole blood samples is associated to MS clinical conditions and may become a potential target for MS treatment and prevention.

Oral Insulin Delivery Using Poly (Styrene Co-Maleic Acid) Micelles in a Diabetic Mouse Model.

The oral delivery of insulin is a convenient and safe physiological route of administration for management of diabetes mellitus. In this study, we developed a poly-(styrene-co-maleic acid) (SMA) micellar system for oral insulin delivery to overcome the rapid degradation of insulin in the stomach, improve its absorption in the intestine, and provide a physiologically-relevant method of insulin to reach portal circulation. The insulin was encapsulated into SMA micelles in a pH-dependent process. The charge and size of the nanoparticles were determined by dynamic light scattering. The insulin loading of the nanoparticles was measured by HPLC. The transport of the SMA-insulin through biological membranes was assessed in vitro using Caco-2 cells, ex vivo rat intestinal section, and in vivo in a streptozotocin-induced diabetes mouse model. SMA-insulin micelles were negatively charged and had a mean diameter of 179.7 nm. SMA-insulin efficiently stimulated glucose uptake in HepG-2 hepatic cells and was transported across the Caco-2 epithelial cells in vitro by 46% and ex vivo across intestinal epithelium by 22%. The animal studies demonstrated that orally-administered SMA-insulin can produce a hypoglycemic effect up to 3 h after administration of one dose. Overall, our results indicate that SMA micelles are capable of the oral delivery of bioactive compounds like insulin and can be effective tools in the management of diabetes.

A New Time-Delay Model for Chaotic Glucose-Insulin Regulatory System

Mathematical modeling is very helpful for noninvasive investigation of glucose-insulin interaction. In this paper, a new time-delay mathematical model is proposed for glucose-insulin endocrine metabolic regulatory feedback system incorporating the [Formula: see text]-cell dynamic and function for regulating and maintaining bloodstream insulin level. The model includes the insulin degradation due to glucose interaction. The dynamical behavior of the model is analyzed and two-dimensional bifurcation diagrams with respect to two essential parameters of the model are obtained. The results show that the time-delay in insulin secretion in response to blood glucose level, and the delay in glucose drop due to increased insulin concentration, can give rise to complex dynamics, such as periodic oscillation. These dynamics are consistent with the biological findings and period doubling cascade and chaotic state which represent metabolic disorder that may lead to diabetes mellitus.

Exploring mechanisms of insulin-degrading enzyme activation and localization in the degradation of amyloid beta and insulin

Exploring mechanisms of insulin-degrading enzyme activation and localization in the degradation of amyloid beta and insulin

Insulin: Trigger and Target of Renal Functions.

Kidney function in metabolism is often underestimated. Although the word “clearance” is associated to “degradation”, at nephron level, proper balance between what is truly degraded and what is redirected to de novo utilization is crucial for the maintenance of electrolytic and acid–basic balance and energy conservation. Insulin is probably one of the best examples of how diverse and heterogeneous kidney response can be. Kidney has a primary role in the degradation of insulin released in the bloodstream, but it is also incredibly susceptible to insulin action throughout the nephron. Fluctuations in insulin levels during fast and fed state add another layer of complexity in the understanding of kidney fine-tuning. This review aims at revisiting renal insulin actions and clearance and to address the association of kidney dysmetabolism with hyperinsulinemia and insulin resistance, both highly prevalent phenomena in modern society.

Abietane Diterpenes as Potential Candidates for the Management of Type 2 Diabetes.

Diabetes mellitus (DM) is considered one of the most common metabolic disorders with an elevated morbidity and mortality rate. It is characterised by a deficiency in insulin secretion or degradation of secreted insulin. Many internal and external factors, such as oxidative stress, obesity and sedentary lifestyle, among others, have been suggested as the major causes of these cell alterations. Diabetes I and II are the most common types of diabetes. Treatment of type I requires insulin injection, while type II can be managed using different synthetic antidiabetic agents. However, their effectiveness is limited as a result of low bioavailability, high cost of drug production, and unfavourable side effects. There is a great need to develop alternative and more active antidiabetic drugs from natural sources. Different forms of natural products have been used since time immemorial as a source of medicine for the purpose of curing numerous human diseases, including diabetes. Secondary metabolites such as polyphenols, flavonoids, terpenoids, alkaloids and several other constituents have direct and indirect roles in controlling such diseases; among them, abietane diterpenes have been reported to display a broad spectrum of promising biological activities including diabetes. This review aimed to summarize existing data from SciFinder (2005-2018) on the biological importance of abietane diterpenes in the prevention and management of type 2 diabetes and closely related diseases.

\u201cOil-soluble\u201d reversed lipid nanoparticles for oral insulin delivery

BackgroundIn this study, we aimed to design a novel oral insulin delivery system, named “oil-soluble” reversed lipid nanoparticles (ORLN), in which a hydrophilic insulin molecule is encapsulated by a phospholipid (PC) shell and dissolved in oil to prevent the enzymatic degradation of insulin. ORLN was characterized by transmission electron microscopy and dynamic light scattering.ResultsIn vitro enzymatic stability studies showed higher concentrations of insulin in cells incubated with ORLN-encapsulated insulin than in those incubated with free insulin solution in artificial intestinal fluid (pH 6.5). The protective effect of ORLN was attributed to its special release behavior and the formulation of the PC shell and oil barrier. Furthermore, an in vivo oral efficacy study confirmed that blood glucose levels were markedly decreased after ORLN administration in both healthy and diabetic mice. In vivo pharmacokinetic results showed that the bioavailability of ORLN-conjugated insulin was approximately 28.7% relative to that of the group subcutaneously administered with an aqueous solution of insulin, indicating enhanced oral absorption.ConclusionsIn summary, the ORLN system developed here shows promise as a nanocarrier for improving the oral absorption of insulin.

Insulin degrading enzyme (IDE) expressed by Chinese hamster ovary (CHO) cells is responsible for degradation of insulin in culture media

Chinese hamster ovary (CHO) cells cultured in serum-free chemically-defined media (CDM) are used for manufacturing of therapeutic proteins. Growth factors, such as insulin are commonly utilized in manufacturing platforms to enhance CHO cell viability and growth. Here we report that insulin is degraded in the culture media over time mainly due to the activity of the insulin degrading enzyme (IDE). Insulin degradation was faster in cell lines that released more IDE, which negatively impacted cell growth and in turn, production titers. Deletion of the IDE gene in a representative CHO cell line nearly abolished insulin degradation in seed train and end-of-production media. In summary, our data suggests that selecting cell lines that have lower IDE expression or targeted-deletion of the IDE gene can improve culture viability and growth for insulin-dependent CHO production platforms.

Glycemic Monitoring and Management in Advanced Chronic Kidney Disease.

Glucose and insulin metabolism in patients with diabetes are profoundly altered by advanced chronic kidney disease (CKD). Risk of hypoglycemia is increased by failure of kidney gluconeogenesis, impaired insulin clearance by the kidney, defective insulin degradation due to uremia, increased erythrocyte glucose uptake during hemodialysis, impaired counterregulatory hormone responses (cortisol, growth hormone), nutritional deprivation, and variability of exposure to oral antihyperglycemic agents and exogenous insulin. Patients with end-stage kidney disease frequently experience wide glycemic excursions, with common occurrences of both hypoglycemia and hyperglycemia. Assessment of glycemia by glycated hemoglobin (HbA1c) is hampered by a variety of CKD-associated conditions that can bias the measure either to the low or high range. Alternative glycemic biomarkers, such as glycated albumin or fructosamine, are not fully validated. Therefore, HbA1c remains the preferred glycemic biomarker despite its limitations. Based on observational data for associations with mortality and risks of hypoglycemia with intensive glycemic control regimens in advanced CKD, an HbA1c range of 7% to 8% appears to be the most favorable. Emerging data on the use of continuous glucose monitoring in this population suggest promise for more precise monitoring and treatment adjustments to permit fine-tuning of glycemic management in patients with diabetes and advanced CKD.

Bacitracin attenuates haemolysis-induced insulin degradation during insulin sensitivity testing: Repurposing an old drug for use in metabolic research.

Haemolysis of serially collected insulin serum samples frequently causes falsely-low measured concentrations because of the release of intracellular insulin degrading enzyme (IDE). We investigated if bacitracin, an in vitro IDE inhibitor, could prevent haemolysis-induced insulin degradation during insulin sensitivity testing. Blood samples were collected from adults undergoing serial sampling for insulin sensitivity. A dose-finding study measured insulin from experimentally haemolysed samples containing five bacitracin concentrations (0-2.5 g/L) and from non-experimentally haemolysed samples. To confirm the utility of bacitracin in the clinical setting, we compared insulin in samples collected with and without 1 g/L bacitracin from a frequently sampled intravenous glucose tolerance test (FSIVGTT), where haemolysis often occurs accidentally. In the dose-finding study, bacitracin 0.25, 1 and 2.5 g/L all maximally prevented insulin degradation in experimentally haemolysed samples. Among FSIVGTT unintentionally haemolysed samples, insulin concentrations from bacitracin-containing samples were significantly higher than from those without bacitracin (P < .01), and not different from non-haemolysed samples obtained simultaneously from a second intravenous catheter (P = .07). Bacitracin did not significantly alter insulin concentrations in non-haemolysed samples. Bacitracin attenuates haemolysis-associated insulin degradation in clinical samples, enabling a more accurate assessment of insulin sensitivity and glucose homeostasis.

Quality Assurance of Commercial Insulin Formulations: Novel Assay Using Infrared Spectroscopy.

Background:For insulins in commercial formulations, degradation can be observed within the certified shelf life when not stored at recommended conditions. Elevated temperatures and exposure to shear forces can cause changes in the secondary structure of the hormone, leading to a decrease in pharmaceutical potency. International pharmacopoeia recommendations for insulin quality monitoring assays mainly rely on liquid chromatography methods. These methods are unable to distinguish between active and inactive forms, both of which may exist in pharmaceutical insulins exposed to stress conditions.Method:Infrared attenuated total reflection spectroscopy has been used for the analysis of insulin dry film preparations using affordable instrumentation. This method can be applied to either formulated insulin specimens or pure insulins obtained by ultrafiltration. Such samples have been stored under different temperatures (0°C, 20°C, and 37°C), and degradation processes have been monitored up to a period of a few months.Results:By analyzing specific shifts of absorption bands in the infrared spectra, which are sensitive to the protein secondary structure, even small structural changes in the hormone become evident. Another option is amide I band deconvolution into individual bands, which can be attributed to secondary structure subunits that are part of the insulin tertiary structure.Conclusion:A novel and innovative method based on infrared attenuated total reflection spectroscopy of insulin dry films is a promising analytical tool for quantifying the degree of insulin degradation, as it provides information on indicating a decrease in biological potency. The established methods for insulin potency assays require animal testing or clamp experiments on people with diabetes.

Stability of Insulin in Total Parenteral Nutrition Solutions

Elneopa NF No. 1 and No. 2 infusions are complete parenteral nutrition solutions packaged as four-chambered bags. They have been used for home parenteral nutrition, with insulin injected into the bags for patients whose blood glucose becomes elevated. In this study, the stability of insulin in No. 1 and No. 2 bags was investigated. The quantity of insulin in Elneopa NF No. 2 was significantly lower than that in Elneopa NF No. 1. When insulin was injected into the upper chamber of either product, decreases in insulin levels were not observed. In contrast, the levels of insulin injected into the lower chamber of both products significantly decreased, with a larger difference in Elneopa NF No. 2. As the amino acid content is different between No. 1 and No. 2, amino acids may be considered a potential cause for the degradation of insulin in the bags. In addition, decreases in insulin levels were observed as the solutions passed through infusion sets just after flushing began, with both Elneopa NF No. 1 and No. 2. In conclusion, the concentration of insulin injected into the Elneopa infusion bags decreases, especially in No. 2 bags, and insulin is absorbed by the infusion sets.

Sequential and Asynchronous Strengthening of the Influence of Temperature on the Endo- and Exocytosis of Insulin in the Isolated Vertebrata Hepatocytes: Summing up Previous Studies.

Insulin internalization and processing of the Insulin Receptor Complex (IRC) inside the cell are important components of the intracellular Mechanism of Insulin Action (MIA). They define the continuation of intracellular signaling of IRC and allow utilization of the parts of the complex after ligand dissociation. Traditionally, changes in the insulin regulatory system associated with the vertebrate phylogenesis have been evaluated by changes of its two elements: the hormone and its receptor. A hormone-competent cell was considered as an evolutionarily completed element of insulin regulatory system. However, previous studies of the isolated hepatocytes of four classes of vertebrates (lamprey, frog, chicken, and rat) revealed significant differences in the state of internalization of 125I-insulin and intracellular IRC processing. Radical differences were noted in the regulation of 125I-insulin internalization and the intracellular fate of the IRC. Here, cytosolic efficient insulin degradation and a complete lack of 125I-insulin exocytosis were observed in the cyclostome cells, whereas in amphibians the hormone underwent lysosomal degradation and showed low levels of exocytosis, while birds and mammals were characterized by high volumes of the excreted 125Iinsulin containing proteolytic 125I-insulin fragments. Despite the established recognition of the importance of the temperature factor, a complete understanding of the molecular mechanisms underlying the temperature effects on MIA is still missing. This poorly studied problem of the MIA temperature dependence can be behind the differences in the effect of temperature on the intracellular action of insulin and IGF-I. In fact, at different phylogenetic stages, successive changes were reported for the temperature dependence of the 125Iinsulin internalization and exocytosis. The following regularities were reported for the effect of temperature on the 125I-insulin internalization in isolated hepatocytes of different origin: complete lack of receptibility of the process to temperature in lampreys, receptibility of the process in a narrow range of low temperatures (0-5°C) in amphibians, and flexible regulation of 125I-insulin internalization in a wide temperature range (6- 37°C) in the cells from endothermic organisms. Reported data make it possible to observe three stages in the alteration of temperature regulation of 125I-insulin internalization (in cells of cyclostomes, amphibians, and endothermic organisms) and two stages of temperature regulation of 125I-insulin exocytosis in cells of amphibians, birds, and mammals. The data presented in this study reflect the specificity of the developmental reorganization of the intracellular MIA regulation and hormone utilization, and emphasize the central role of temperature in selective MIA formation during vertebrate phylogenesis.

Implantable powder-carrying microneedles for transdermal delivery of high-dose insulin with enhanced activity

Recently, numerous transdermal drug delivery systems have been developed for safe and efficient delivery of biopharmaceuticals. Dissolving microneedles (DMNs) are one such drug delivery system, which have been developed to treat a variety of diseases in a minimally invasive manner. However, current DMN fabrication methods involve a reconstitution process of the therapeutics, which can result in degradation of the therapeutics or limited loading capacity for a reasonable application size. In the present study, we developed self-administrative powder-carrying microneedles (PCMs), lacking a reconstitution step, which implant insulin powder directly inside the skin without using a sticky patch. Compared with DMNs in the same geometries, the PCMs delivered the required dose in a more condensed form without considering insulin solubility and degradation during the fabrication process. Moreover, PCMs showed enhanced long-term stability and prolonged release kinetics, which could be utilized to treat diabetes without apparent safety issues. This implantable PCM technique will greatly impact the future of transdermal drug delivery systems because it is applicable to any type of therapeutic available in a dry powder formulation for a wide variety of biomedical applications.

Inhibition of amyloid fibrillation, enzymatic degradation and cytotoxicity of insulin at carboxyl tailored gold-aryl nanoparticles surface

Insulin fibrillation complicated its oral delivery in diabetes therapy. pH sensitive carboxylate-terminated gold-carbon nanoparticles, AuNPs-C6H4-4-COOH, inhibited amyloid fibrillation and disintegrated the preformed insulin fibrils under amyloidogenic conditions. Transmission electron microscopy and X-ray photoelectron spectroscopy results support the immobilization of insulin on the nanoparticles surface. In contrast to native insulin, gold insulin bioconjugate exhibited a significant inhibitory effect against the proteolytic enzymatic activity of pepsin and trypsin while passaging through the stomach and gastrointestinal tract. Fluorescence solution studies supported the insulin fibrils dissociation over the gold nanoparticles surface in the presence of thioflavin T dye. In addition, fluorescence quenching studies were carried out to estimate the binding constant and the number of binding sites in insulin available for the gold nanoparticles. The outstanding hemocompatibility of the insulin bioconjugate in the presence of diabetic and non-diabetic red blood cells supports its significance in insulin drug delivery. With the aid of molecular docking calculations, we were able to verify the mediation of hydrophobic and hydrogen bonding interactions of benzoic acid with the fibril-forming region of insulin, which prevents these residues from the unfolding necessary for fibrillation. The robust gold-carbon nanoparticles mediation can be extended to defibrillate other proteins with nanomedicine therapies in Alzheimer’s, Parkinson’s, Huntington’s and infectious prion diseases.