What Is The Definition Of Transport Protein?

Transport proteins are essential for life, but what exactly are they? Let’s explore the definition, function, and significance of these vital molecules, all while highlighting the resources available at worldtransport.net to deepen your understanding of the transportation sector.

1. What Is the Definition of Transport Protein?

Transport proteins are proteins that facilitate the movement of molecules across biological membranes. They’re the gatekeepers and delivery trucks of the cellular world, ensuring that essential substances get where they need to go. Think of them as tiny, highly specialized vehicles facilitating the flow of goods within the bustling city of a cell, and just like in any major transportation hub, understanding their roles is crucial for comprehending the entire system. To further enhance your understanding of transport mechanisms and their role in biological systems, worldtransport.net offers resources covering advancements in logistics and supply chain management.

1.1. Expanding on the Definition of Transport Protein

Transport proteins are integral membrane proteins, meaning they are embedded within the lipid bilayer of cell membranes. They act as intermediaries, helping hydrophilic (water-soluble) molecules, which cannot easily diffuse across the hydrophobic (water-repelling) core of the membrane, to enter or exit the cell or specific cellular compartments.

Specificity: These proteins are highly specific, often binding to only one or a few types of molecules.
Types: There are two main types: carrier proteins and channel proteins, each with distinct mechanisms of action.
Function: They play a crucial role in maintaining cellular homeostasis, nutrient uptake, and waste removal.

1.2. Why Are Transport Proteins Important?

Transport proteins are vital because they enable cells to control their internal environment. Without them, cells would be unable to:

Acquire essential nutrients: Glucose, amino acids, and other vital nutrients require transport proteins to enter cells.
Eliminate waste products: Metabolic waste and toxins must be efficiently removed from cells to prevent damage.
Maintain ion balance: Transport proteins regulate the concentration of ions like sodium, potassium, and calcium, which are crucial for nerve function, muscle contraction, and other cellular processes.
Signal transduction: Some transport proteins are involved in transmitting signals across the cell membrane.

1.3. Transport Proteins and worldtransport.net

While worldtransport.net primarily focuses on the broader aspects of the transportation industry, understanding the fundamental principles of transport at the cellular level can provide valuable insights into the complexities of logistics and supply chain management. Efficient transport, whether it’s of goods across a country or molecules across a cell membrane, relies on optimized pathways, specialized carriers, and regulatory mechanisms.

2. What Are the Main Types of Transport Proteins?

There are two primary categories of transport proteins: channel proteins and carrier proteins.

2.1. Channel Proteins: The Open Door

Channel proteins form a pore or tunnel through the membrane, allowing specific molecules to pass through. They do not bind to the molecules they transport, and the movement is always down the concentration gradient (from an area of high concentration to an area of low concentration).

Mechanism: Create a hydrophilic pathway across the membrane.
Selectivity: Based on size and charge of the molecule.
Examples: Aquaporins (water channels), ion channels.

2.2. Carrier Proteins: The Attentive Porter

Carrier proteins bind to the molecule they transport, undergoing a conformational change that moves the molecule across the membrane. This process can be either passive (facilitated diffusion) or active (requiring energy).

Mechanism: Bind to the solute and change shape to shuttle it across the membrane.
Specificity: High affinity for specific molecules.
Types:
- Uniport: Transports one type of molecule.
- Symport: Transports two or more different molecules in the same direction.
- Antiport: Transports two or more different molecules in opposite directions.

2.3. Comparing Channel and Carrier Proteins

Feature	Channel Proteins	Carrier Proteins
Transport Mechanism	Pore or tunnel	Binding and conformational change
Binding	No binding to transported molecule	Binds to transported molecule
Energy Requirement	Passive (down concentration gradient)	Passive (facilitated diffusion) or Active (requires energy)
Rate of Transport	Generally faster	Generally slower

2.4 The significance of understanding different transport systems

The choice between channel and carrier proteins depends on the specific needs of the cell and the nature of the molecule being transported. To draw a parallel from real-world transportation, channel proteins are akin to highways allowing a constant flow of traffic, while carrier proteins are like specialized trucks delivering specific goods to designated locations. Understanding these mechanisms is crucial for comprehending how cells maintain their internal environment and respond to external stimuli. To extend your understanding of optimizing routes and specialized transport, worldtransport.net offers expert analyses on transportation logistics and supply chain solutions.

3. How Do Transport Proteins Work?

The function of transport proteins is multifaceted, involving several intricate mechanisms that ensure efficient and selective movement of molecules across cell membranes.

3.1. Passive Transport: Riding the Concentration Gradient

Passive transport, also known as facilitated diffusion, relies on the concentration gradient to drive the movement of molecules across the membrane. This process does not require energy input from the cell.

Mechanism: Molecules move from an area of high concentration to an area of low concentration, facilitated by the transport protein.
Types: Can be mediated by both channel and carrier proteins.
Examples:
- Glucose transport: The GLUT family of carrier proteins facilitates the movement of glucose across cell membranes down its concentration gradient.
- Ion channels: Allow the flow of ions like sodium (Na+) or potassium (K+) down their electrochemical gradients.

3.2. Active Transport: Going Against the Flow

Active transport involves the movement of molecules against their concentration gradient, requiring energy input from the cell, typically in the form of ATP (adenosine triphosphate).

Mechanism: The transport protein uses energy to pump the molecule across the membrane, from an area of low concentration to an area of high concentration.
Types:
- Primary active transport: Directly uses ATP to transport molecules. Example: Sodium-potassium pump (Na+/K+ ATPase).
- Secondary active transport: Uses the electrochemical gradient created by primary active transport to move other molecules. Examples: Symporters and antiporters that move glucose or amino acids along with sodium ions.

3.3. Conformational Changes: The Key to Carrier Protein Function

Carrier proteins undergo conformational changes to transport molecules across the membrane. This process involves several steps:

Binding: The molecule binds to a specific site on the carrier protein.
Conformational Change: The protein changes shape, exposing the molecule to the other side of the membrane.
Release: The molecule is released from the carrier protein into the cell (or outside of the cell).
Return: The carrier protein returns to its original conformation, ready to bind another molecule.

3.4. The Role of ATP: Fueling Active Transport

ATP is the primary energy currency of the cell, providing the energy needed for active transport. The hydrolysis of ATP releases energy that is used by transport proteins to move molecules against their concentration gradients.

Example: The sodium-potassium pump uses the energy from ATP hydrolysis to pump three sodium ions out of the cell and two potassium ions into the cell, maintaining the electrochemical gradient essential for nerve function and cell volume regulation.

3.5. Insights from Cellular Transport to Global Logistics

The underlying principles of transport proteins – facilitated movement, energy utilization, and conformational changes – mirror the strategies employed in global logistics and transportation networks. Just as cells optimize the transport of essential molecules, worldtransport.net explores how industries streamline the movement of goods and resources to meet global demands efficiently.

4. What Are Some Examples of Transport Proteins?

Transport proteins are diverse and highly specialized, each designed to transport specific molecules across cell membranes. Here are some notable examples:

4.1. Aquaporins: Water Channels

Aquaporins are channel proteins that facilitate the rapid movement of water across cell membranes. They are essential for maintaining water balance in cells and tissues.

Function: Allow water to move rapidly in and out of cells.
Location: Found in kidney cells, red blood cells, and plant cells.
Significance: Crucial for kidney function, regulating blood volume, and maintaining plant cell turgor pressure.

4.2. Glucose Transporters (GLUTs): Sugar Delivery

GLUTs are a family of carrier proteins that facilitate the transport of glucose across cell membranes. They are essential for providing cells with the energy they need to function.

Function: Transport glucose from the bloodstream into cells.
Types: Different GLUT isoforms are found in different tissues, each with specific properties and regulatory mechanisms. For example, GLUT4 is insulin-dependent and is found in muscle and fat cells.
Significance: Important for regulating blood sugar levels and providing energy to cells.

4.3. Sodium-Potassium Pump (Na+/K+ ATPase): Maintaining Ion Balance

The sodium-potassium pump is an active transport protein that pumps sodium ions (Na+) out of the cell and potassium ions (K+) into the cell, maintaining the electrochemical gradient essential for nerve function, muscle contraction, and cell volume regulation.

Function: Maintains the Na+ and K+ gradients across the cell membrane.
Mechanism: Uses ATP to pump 3 Na+ ions out of the cell and 2 K+ ions into the cell.
Significance: Essential for nerve impulse transmission, muscle contraction, and maintaining cell volume.

4.4. Ion Channels: Gatekeepers of Electrical Signals

Ion channels are channel proteins that allow the selective passage of ions (such as Na+, K+, Ca2+, and Cl-) across cell membranes. They are crucial for generating electrical signals in nerve and muscle cells.

Function: Allow the flow of specific ions across the cell membrane.
Types: Voltage-gated, ligand-gated, and mechanically-gated channels.
Significance: Essential for nerve impulse transmission, muscle contraction, and sensory perception.

4.5. ABC Transporters: The Multidrug Resistance Protectors

ABC (ATP-binding cassette) transporters are a large family of active transport proteins that use ATP to transport a wide variety of molecules across cell membranes, including drugs, toxins, and lipids.

Function: Transport a wide range of molecules across cell membranes.
Significance: Involved in drug resistance in cancer cells, lipid transport, and detoxification.

4.6. Analogies to Real-World Transport Systems

Understanding these specific transport proteins not only illuminates cellular processes but also offers insightful analogies to real-world transport systems. Aquaporins are like water pipelines, GLUTs are like sugar distribution networks, and the sodium-potassium pump is akin to a sophisticated waste management system that keeps the cellular environment balanced. You can find additional information on innovative transport solutions, visit worldtransport.net, your go-to source for the latest trends in transportation.

5. What Is the Role of Transport Proteins in Diseases?

Dysfunction or defects in transport proteins can lead to a variety of diseases. Their critical role in maintaining cellular homeostasis means that any disruption can have significant consequences.

5.1. Cystic Fibrosis: A Chloride Channel Defect

Cystic fibrosis is a genetic disorder caused by mutations in the CFTR (cystic fibrosis transmembrane conductance regulator) gene, which encodes a chloride channel protein.

Mechanism: Defective CFTR protein leads to impaired chloride ion transport across cell membranes.
Consequences: Results in the production of thick, sticky mucus that clogs the lungs, pancreas, and other organs.
Symptoms: Difficulty breathing, chronic lung infections, digestive problems.

5.2. Diabetes Mellitus: Glucose Transport Issues

Diabetes mellitus is a metabolic disorder characterized by high blood sugar levels. Defects in glucose transport proteins play a significant role in the development of this disease.

Mechanism:
- Type 1 diabetes: Autoimmune destruction of pancreatic beta cells, leading to insulin deficiency. Without insulin, glucose cannot be efficiently transported into cells via GLUT4.
- Type 2 diabetes: Insulin resistance, where cells become less responsive to insulin. This can be due to defects in insulin signaling pathways or reduced expression of GLUT4.
Consequences: High blood sugar levels, leading to various complications such as heart disease, kidney disease, and nerve damage.

5.3. Alzheimer’s Disease: The Role of Transport Proteins in Amyloid-Beta Clearance

Alzheimer’s disease is a neurodegenerative disorder characterized by the accumulation of amyloid-beta plaques in the brain. Transport proteins are involved in the clearance of amyloid-beta from the brain, and defects in these proteins may contribute to the development of the disease.

Mechanism:
- Reduced clearance: Defects in transport proteins like LRP1 (LDL receptor-related protein 1) can impair the removal of amyloid-beta from the brain.
- Increased accumulation: This leads to the accumulation of amyloid-beta plaques, which are toxic to neurons and contribute to cognitive decline.
Consequences: Memory loss, cognitive impairment, and dementia.

5.4. Wilson’s Disease: Copper Transport Gone Wrong

Wilson’s disease is a genetic disorder caused by mutations in the ATP7B gene, which encodes a copper-transporting ATPase.

Mechanism: Defective ATP7B protein leads to impaired copper transport and excretion.
Consequences: Copper accumulates in the liver, brain, and other organs, causing damage.
Symptoms: Liver disease, neurological problems, and psychiatric symptoms.

5.5. Drug Resistance in Cancer: ABC Transporters to Blame

ABC transporters play a significant role in drug resistance in cancer cells. These proteins can pump chemotherapeutic drugs out of cancer cells, reducing their effectiveness.

Mechanism: Overexpression of ABC transporters like P-glycoprotein (MDR1) in cancer cells.
Consequences: Reduced intracellular drug concentration, leading to drug resistance and treatment failure.

5.6. Linking Cellular Dysfunction to Macro-Level Challenges

These examples illustrate how essential transport proteins are for maintaining health. When these proteins malfunction, the resulting diseases can have devastating effects.

6. How Are Transport Proteins Studied?

Studying transport proteins involves a variety of techniques aimed at understanding their structure, function, and regulation.

6.1. Biochemical Assays: Measuring Transport Activity

Biochemical assays are used to measure the activity of transport proteins in vitro. These assays can provide information about the rate of transport, substrate specificity, and the effects of inhibitors or activators.

Techniques:
- Uptake assays: Measure the rate at which a substrate is transported into cells or vesicles.
- Binding assays: Determine the affinity of a transport protein for its substrate.
- Enzyme kinetics: Analyze the kinetics of transport, including Km (Michaelis constant) and Vmax (maximum velocity).

6.2. Electrophysiology: Studying Ion Channels

Electrophysiology is a technique used to study the electrical properties of cells and ion channels. It involves measuring the flow of ions across the cell membrane.

Techniques:
- Patch-clamp technique: Allows the study of single ion channels by isolating a small patch of cell membrane.
- Voltage-clamp technique: Controls the membrane potential and measures the resulting current flow.
- Current-clamp technique: Measures the membrane potential in response to current injection.

6.3. Structural Biology: Unraveling the 3D Structure

Structural biology techniques, such as X-ray crystallography and cryo-electron microscopy (cryo-EM), are used to determine the three-dimensional structure of transport proteins. This information can provide insights into the mechanism of transport and the binding site for substrates.

Techniques:
- X-ray crystallography: Involves crystallizing the protein and then bombarding it with X-rays to determine its structure.
- Cryo-EM: Involves freezing the protein in a thin layer of ice and then imaging it with an electron microscope.

6.4. Molecular Biology: Manipulating Transport Protein Genes

Molecular biology techniques are used to manipulate the genes encoding transport proteins. This allows researchers to study the effects of mutations on protein function and to identify regulatory elements that control gene expression.

Techniques:
- Gene cloning: Isolating and copying the gene encoding the transport protein.
- Site-directed mutagenesis: Introducing specific mutations into the gene to study their effects on protein function.
- Gene expression analysis: Measuring the levels of mRNA and protein to study the regulation of gene expression.

6.5. Cell Biology: Visualizing Transport Proteins in Cells

Cell biology techniques are used to visualize transport proteins in cells and to study their localization and trafficking.

Techniques:
- Immunofluorescence microscopy: Uses antibodies to label transport proteins and visualize them in cells.
- Confocal microscopy: Provides high-resolution images of cells and tissues.
- Live-cell imaging: Allows the study of transport protein dynamics in real-time.

6.6. Bridging Microscopic Insights with Macroscopic Understanding

These techniques provide valuable insights into the world of transport proteins. Understanding these processes is essential for developing new therapies for diseases caused by defects in transport proteins. These techniques are like the diagnostic tools and analytical methods used in the transportation industry to assess efficiency, safety, and performance. To see how worldtransport.net covers the analytical side of transportation, explore our analytics and data-driven decision-making articles.

7. What Are the Latest Advances in Transport Protein Research?

Research on transport proteins is a dynamic field, with new discoveries and advances being made all the time.

7.1. New Structures of Transport Proteins

Recent advances in cryo-EM have led to the determination of high-resolution structures of many transport proteins, providing new insights into their mechanisms of action.

Example: The structure of the human glucose transporter GLUT1 has been determined by cryo-EM, revealing the conformational changes that occur during glucose transport.

7.2. New Inhibitors and Activators of Transport Proteins

Researchers are developing new inhibitors and activators of transport proteins as potential therapeutic agents.

Example: New inhibitors of the sodium-glucose cotransporter 2 (SGLT2) are being used to treat type 2 diabetes by blocking the reabsorption of glucose in the kidneys.

7.3. Transport Proteins and Drug Delivery

Transport proteins are being exploited for drug delivery. By targeting specific transport proteins, drugs can be selectively delivered to certain cells or tissues.

Example: The use of peptide transporters to deliver drugs across the blood-brain barrier.

7.4. Transport Proteins and Personalized Medicine

Advances in genomics and proteomics are leading to a better understanding of the role of transport proteins in personalized medicine.

Example: Identifying genetic variations in transport protein genes that may affect drug response.

7.5. The Future of Transport Protein Research

The future of transport protein research is bright, with new technologies and approaches promising to reveal even more about these essential proteins. These advances hold great promise for the development of new therapies for a wide range of diseases.

7.6. Parallels in Transportation Innovation

Just as transport protein research is constantly evolving, the transportation industry is also undergoing rapid innovation. To learn more about the newest developments in transport, stay connected with worldtransport.net for breaking stories and in-depth analysis.

8. How Do Transport Proteins Relate to Membrane Permeability?

Transport proteins are critical components that determine the permeability of cell membranes. Understanding how these proteins function sheds light on the overall membrane dynamics and cellular activities.

8.1. Membrane Permeability Basics

Cell membranes are primarily composed of a lipid bilayer, which is inherently impermeable to many molecules, particularly ions and polar substances. This impermeability is essential for maintaining distinct cellular environments.

Selective Barrier: The lipid bilayer acts as a barrier, preventing the free diffusion of hydrophilic molecules while allowing small, nonpolar molecules like oxygen and carbon dioxide to pass through.
Hydrophobic Core: The hydrophobic core of the lipid bilayer repels charged and polar molecules, necessitating specialized mechanisms for their transport.

8.2. Role of Transport Proteins in Enhancing Permeability

Transport proteins enhance membrane permeability by providing pathways or mechanisms for specific molecules to cross the membrane. These proteins can either form channels or bind to the molecule and undergo conformational changes to facilitate transport.

Increased Specificity: Unlike simple diffusion, transport proteins allow cells to selectively control which molecules enter or exit, maintaining precise intracellular conditions.
Facilitated Diffusion: Channel proteins and carrier proteins operating through facilitated diffusion increase the permeability of the membrane without requiring energy input, following the concentration gradient.
Active Transport: Active transport proteins, on the other hand, use energy (ATP) to move molecules against their concentration gradient, further enhancing permeability while maintaining cellular homeostasis.

8.3. Types of Transport Proteins and Their Impact on Membrane Permeability

The type of transport protein present in a membrane directly impacts its permeability characteristics.

Channel Proteins: These form open pores allowing specific ions or small molecules to flow through rapidly. For example, aquaporins dramatically increase water permeability in certain cells.
Carrier Proteins: These bind to specific solutes and undergo conformational changes, making them slower but more selective. The presence of different carrier proteins allows cells to regulate the transport of a wide range of substances, from sugars to amino acids.

8.4. Regulation of Transport Proteins

Cells can regulate the number and activity of transport proteins to adjust membrane permeability in response to changing conditions.

Expression Levels: Cells can increase or decrease the synthesis of specific transport proteins, altering the number available in the membrane.
Post-Translational Modifications: Phosphorylation or other modifications can change the activity or localization of transport proteins.
trafficking: Transport proteins can be inserted into or removed from the membrane through vesicular trafficking, providing a rapid way to change permeability.

8.5. Clinical Implications

Understanding the relationship between transport proteins and membrane permeability is crucial in medicine.

Drug Delivery: Designing drugs that can effectively cross cell membranes often involves targeting specific transport proteins.
Disease Mechanisms: Many diseases, such as cystic fibrosis and diabetes, involve defects in transport proteins that alter membrane permeability and cellular function.

8.6. Drawing Parallels with Global Logistics

The selective control of membrane permeability by transport proteins mirrors the strategies employed in global logistics to selectively move goods across borders. Just as cells rely on transport proteins to maintain internal balance, worldtransport.net explores how industries streamline the movement of goods and resources to meet global demands efficiently.

9. What Is the Significance of Transport Protein Research for Drug Development?

Transport protein research plays a pivotal role in modern drug development, offering insights and opportunities to enhance drug efficacy, specificity, and safety.

9.1. Understanding Drug Transport

Many drugs need to cross cell membranes to reach their intracellular targets. Transport proteins often mediate this process, either facilitating drug entry or efflux from cells.

Influx Transporters: These proteins promote the uptake of drugs into cells, increasing their intracellular concentration and therapeutic effect.
Efflux Transporters: These proteins pump drugs out of cells, reducing their intracellular concentration and potentially leading to drug resistance.

9.2. Enhancing Drug Delivery

Targeting transport proteins can improve drug delivery to specific tissues or cells.

Exploiting Influx Transporters: By designing drugs that are substrates for specific influx transporters, drug uptake can be increased in target cells.
Inhibiting Efflux Transporters: Inhibiting efflux transporters can prevent drugs from being pumped out of cells, increasing their intracellular concentration and efficacy.

9.3. Overcoming Drug Resistance

Drug resistance is a major challenge in cancer therapy and other fields. Transport proteins, particularly efflux transporters, often play a key role in this phenomenon.

Mechanisms of Resistance: Cancer cells can upregulate the expression of efflux transporters, reducing the intracellular concentration of chemotherapeutic drugs.
Strategies to Overcome Resistance:
- Developing Inhibitors: Inhibitors of efflux transporters can restore drug sensitivity in resistant cells.
- Designing Alternative Drugs: Developing drugs that are not substrates for efflux transporters can bypass resistance mechanisms.

9.4. Personalized Medicine

Genetic variations in transport protein genes can affect drug response, making transport protein research valuable for personalized medicine.

Pharmacogenomics: Identifying genetic polymorphisms in transport protein genes that influence drug absorption, distribution, metabolism, and excretion (ADME).
Tailored Therapies: Using this information to tailor drug selection and dosing to individual patients, optimizing therapeutic outcomes and minimizing adverse effects.

9.5. Blood-Brain Barrier (BBB) Penetration

Delivering drugs to the brain is particularly challenging due to the BBB, a highly selective barrier that restricts the passage of many substances. Transport proteins at the BBB can be targeted to enhance drug delivery to the brain.

BBB Transporters: Identifying and exploiting transporters that can carry drugs across the BBB.
Nanoparticle Strategies: Using nanoparticles to encapsulate drugs and target them to specific transporters at the BBB.

9.6. Analogies in Transportation Logistics

The challenges in drug delivery—crossing biological barriers, overcoming resistance, and tailoring therapies to individual needs—find parallels in the world of transportation logistics. Understanding these intricate processes is essential for optimizing drug development and improving patient outcomes.

10. Frequently Asked Questions (FAQs) About Transport Proteins

Here are some frequently asked questions about transport proteins to enhance your understanding of these essential molecules.

Q1: What exactly are transport proteins?

Transport proteins are specialized proteins that facilitate the movement of molecules across cell membranes, enabling essential substances to enter and exit cells.

Q2: What are the main types of transport proteins?

The main types are channel proteins and carrier proteins. Channel proteins form pores for molecules to pass through, while carrier proteins bind to molecules and undergo conformational changes to transport them.

Q3: How do transport proteins work?

Transport proteins work through passive transport (facilitated diffusion) or active transport. Passive transport follows the concentration gradient, while active transport requires energy to move molecules against the gradient.

Q4: Can you give some examples of transport proteins?

Examples include aquaporins (water channels), GLUTs (glucose transporters), the sodium-potassium pump, and ion channels.

Q5: What role do transport proteins play in diseases?

Defects or dysfunction in transport proteins can lead to diseases like cystic fibrosis, diabetes, Alzheimer’s, and Wilson’s disease.

Q6: How are transport proteins studied?

Transport proteins are studied using biochemical assays, electrophysiology, structural biology, molecular biology, and cell biology techniques.

Q7: What are some recent advances in transport protein research?

Recent advances include determining new structures of transport proteins, developing new inhibitors and activators, and exploiting transport proteins for drug delivery.

Q8: How do transport proteins relate to membrane permeability?

Transport proteins enhance membrane permeability by providing pathways for specific molecules to cross the membrane, either through facilitated diffusion or active transport.

Q9: What is the significance of transport protein research for drug development?

Transport protein research helps enhance drug efficacy, specificity, and safety by understanding drug transport mechanisms and designing strategies to overcome drug resistance.

Q10: Where can I find more information about transport proteins?

For more information about transport proteins and related topics in transportation and logistics, visit worldtransport.net.

By understanding the definition, types, mechanisms, and significance of transport proteins, we gain valuable insights into the fundamental processes that sustain life. worldtransport.net provides a wealth of resources to further explore the fascinating world of transportation, from the microscopic to the macroscopic.

Explore worldtransport.net today to discover more insights, trends, and solutions that are shaping the future of transportation in the USA and beyond. Visit our website at worldtransport.net, or contact us at Address: 200 E Randolph St, Chicago, IL 60601, United States. Phone: +1 (312) 742-2000.