Growth Factors
CD Antigens
Enzymes
Viral Antigens
Recombinant Proteins
Natural Proteins
Monoclonal Antibodies
Cytokines
Polyclonal Antibodies
Neurotrophins
Chemokines
Hormones
Natural Proteins
Introduction
Definition and Classification
Natural proteins are large, complex molecules made up of amino acids and are essential for the structure, function, and regulation of the body’s tissues and organs. They are classified based on their structure and function into several categories:
- Fibrous Proteins: These are elongated and insoluble, providing structural support (e.g., collagen, keratin).
- Globular Proteins: These are compact and soluble, playing roles in metabolic processes (e.g., enzymes, hemoglobin).
- Membrane Proteins: These are associated with cell membranes and involved in signaling and transport (e.g., receptors, ion channels).
Biological Properties
Key Biological Properties:
- Structure: Proteins have primary, secondary, tertiary, and quaternary structures that determine their function.
- Expression Patterns: Protein expression varies across different tissues and developmental stages.
- Tissue Distribution: Proteins are distributed throughout the body, with specific proteins localized to particular tissues (e.g., myosin in muscles, insulin in the pancreas).
Biological Functions
Primary Biological Functions:
- Enzymatic Activity: Catalyzing biochemical reactions.
- Structural Support: Providing strength and support to cells and tissues.
- Transport: Carrying molecules across cell membranes and within the bloodstream.
- Immune Responses: Recognizing and neutralizing pathogens (e.g., antibodies).
- Pathogen Recognition: Identifying and binding to foreign molecules to initiate an immune response.
Modes of Action
Mechanisms with Other Molecules and Cells:
- Binding Partners: Proteins interact with other molecules through specific binding sites.
- Downstream Signaling Cascades: Binding of a protein to its partner can trigger a series of intracellular events, leading to a cellular response.
Regulatory Mechanisms
Regulatory Mechanisms:
- Transcriptional Regulation: Control of protein expression at the gene level.
- Post-Translational Modifications: Chemical modifications after protein synthesis that affect protein function (e.g., phosphorylation, glycosylation).
Applications
In Biomedical Research:
- Diagnostic Tools: Proteins are used as biomarkers for disease diagnosis.
- Therapeutic Strategies: Proteins are used in treatments (e.g., insulin for diabetes, monoclonal antibodies for cancer).
Role in the Life Cycle
Role Throughout the Life Cycle:
- Development: Proteins are crucial for growth and development.
- Aging: Changes in protein function and expression are associated with aging.
- Disease: Abnormal protein function can lead to diseases (e.g., Alzheimer’s, cystic fibrosis).
