ENZYMES, GROWTH FACTORS, PROTEINS, AND RECEPTORS

Catalase

What enzyme differentiates Staphylococcus from Streptococcus and converts hydrogen peroxide to water and oxygen?

Coagulase

What enzyme produced by S. aureus acts with a plasma factor to convert fibrinogen to a fibrin clot, helping the bacteria evade phagocytosis?

Hyaluronidase

What enzyme breaks down hyaluronic acid and proteoglycans in connective tissues, acting as a "spreading factor" for bacteria?

Staphylokinase

What enzyme results in fibrinolysis, degrading clots and allowing bacteria to spread?

β-Lactamase

What enzyme produced by S. aureus confers resistance to penicillin?

Lipase

What enzyme degrades fats and oils, such as those found in sebaceous glands?

Proteinase

What general enzyme is responsible for degrading proteins?

α Hemolysin

What hemolysin causes hemolysis of RBCs, skin necrosis, and the release of cytokines?

β toxin Hemolysin

What hemolysin acts as a sphingomyelinase on the lipid membrane?

𝛿 toxin Hemolysin

What hemolysin disrupts biologic membranes and may contribute to diarrheal pathogenesis?

𝛾 Hemolysin

What hemolysin functions as a leukocidin, lysing WBCs and leading to inflammation and necrosis?

Panton Valentine Leukocidin (PVL)

What special leukocidin, found in CA-MRSA, lyses WBCs and forms pores in host cell membranes?

Exfoliative toxin

What superantigenic toxin dissolves the mucopolysaccharide matrix of the skin, causing generalized desquamation?

Toxic Shock Syndrome Toxin 1 (TSST1)

What superantigen binds with MHC II, promoting T-cell stimulation and leading to toxic shock syndrome?

Enterotoxin (Staphylococcus)

What heat-stable superantigen from Staphylococcus induces diarrhea and vomiting by stimulating gut neural receptors?

Streptokinase (Fibrinolysin)

What enzyme produced by Streptococcus allows bacteria to escape blood clots and invade the host?

Deoxyribonuclease (Streptodornase)

What enzyme, also known as Streptodornase, lyses DNA and is used for enzymatic cleaning of pus/abscesses?

Streptococcal Pyrogenic Exotoxins (Spe)

What superantigens (types A, B, and C) stimulate T-cells for cytokine release, cause fever, and are associated with scarlet fever and Streptococcal TSS?

Streptolysin S

What non-antigenic streptolysin causes hemolysis and is oxygen stable?

Streptolysin O

What antigenic streptolysin causes hemolysis, is oxygen labile, and is used as a biomarker for Anti-Streptolysin O (ASO) titers?

Peptidases (host)

What host enzymes activate envelope and pre-membrane proteins of the Dengue virus during replication?

Botulinum toxin

What neurotoxin from C. botulinum causes flaccid paralysis by cleaving SNARE proteins at presynaptic motor neurons, preventing acetylcholine release?

Tetanospasmin

What neurotoxin from C. tetani causes spastic paralysis by allowing continuous neurotransmitter release at the receptor?

Clostridium perfringens Enterotoxin (CPE)

What toxin causes hypersecretion in the small intestines, leading to intense diarrhea?

α-toxin (Lecithinase)

What invasive toxin of C. perfringens lyses lecithin in cell walls, causes platelet aggregation, and promotes anaerobic conditions for bacterial growth?

θ-toxin (Cytolysin)

What invasive toxin of C. perfringens has hemolytic and necrotizing effects, forming pores in cells?

ε-toxin (Epsilon)

What invasive toxin of C. perfringens causes edema and hemorrhage?

DNAse (C. perfringens)

What spreading factor of C. perfringens is responsible for lysing DNA?

Collagenase (C. perfringens)

What spreading factor of C. perfringens breaks down collagen?

Toxin A (C. difficile)

What enterotoxin produced by C. difficile causes watery or bloody diarrhea?

Toxin B (C. difficile)

What cytotoxin produced by C. difficile causes plaques and microabscesses in the colon?

Listeriolysin O (LLO)

What protease produced by Listeria monocytogenes helps the bacteria escape phagocytosis by being activated at low vacuolar pH?

Collagenase (SANTYL)

What enzyme-based ointment is used for chemical/enzymatic debridement to liquefy and remove dead tissue?

Body's own enzymes (wound healing)

What naturally occurring substances, along with neutrophils and proteases, are utilized in autolytic debridement to clean wounds?

Proteases (wound cleaning)

What enzymes, released by neutrophils, help clean wounds and are involved in autolytic debridement?

Platelet-derived growth factor (PDGF)

What growth factor is the strongest chemotactic factor for fibroblasts, stimulates angiogenesis, collagen synthesis, and enhances re-epithelialization?

Vascular endothelial growth factor (VEGF)

What growth factor is a mitogen for endothelial cells, primarily responsible for angiogenesis, and is proinflammatory?

Tumor Necrosis Factor (TNF)

What cytokine is a major source released by neutrophils during inflammation?

Fibroblast growth factor (FGF)

What growth factor stimulates angiogenesis by promoting endothelial cell proliferation and migration, and induces mitogenesis for mesoderm and neuroectoderm?

Hepatocyte growth factor (HGF)

What growth factor stimulates fibroblasts, keratinocytes, and myoblasts, but suppresses inflammation and granulation tissue formation?

Keratinocyte growth factor

What growth factor, with significant homology to FGF, specifically stimulates keratinocytes?

Epidermal growth factor (EGF)

What growth factor stimulates the proliferation and migration of all epithelial cell types?

Transforming growth factor-alpha (TGF-ɑ)

What growth factor has homology to EGF, binds to the EGF receptor, and is mitogenic and chemotactic for epidermal and endothelial cells?

Transforming growth factor-beta (TGF-β)

What growth factor (with isoforms β1, β2, β3) stimulates angiogenesis and leukocyte chemotaxis, with TGF-β1 stimulating wound matrix production and TGF-β3 inhibiting scar formation?

Insulin-like growth factors (IGF-1, IGF-2)

What growth factors promote protein/extracellular matrix synthesis and increase membrane glucose transport?

Interleukin-1 (IL-1)

What proinflammatory cytokine stimulates angiogenesis, re-epithelialization, and tissue remodeling?

Interleukin-4 (IL-4)

What cytokine is known for enhancing collagen synthesis?

Interleukin-6 (IL-6)

What cytokine stimulates inflammation, angiogenesis, re-epithelialization, collagen deposition, and tissue remodeling?

Activin

What growth factor stimulates granulation tissue formation, keratinocyte differentiation, and re-epithelialization?

Angiopoietin-1/-2

What growth factors are primarily involved in stimulating angiogenesis?

CX3CL1

What cytokine stimulates inflammation, angiogenesis, and collagen deposition?

Granulocyte macrophage colony stimulating factor

What growth factor stimulates macrophage differentiation and proliferation?

Cytokines (general function)

What polypeptides stimulate cellular migration, proliferation, and function, and may overlap with growth factors?

Epidermal Growth Factor (spray)

What growth factor, when applied as a spray, promoted wound healing but was removed from the market due to high costs?

EGF receptor

What receptor binds Transforming Growth Factor-alpha (TGF-ɑ)?

Fc region of IgG

What region of IgG does Staphylococcus aureus Protein A bind to, thereby decreasing opsonization and phagocytosis?

MHC II (Major Histocompatibility Complex II)

What host molecule does Toxic Shock Syndrome Toxin 1 (TSST1) bind to, promoting T-cell stimulation?

Neural receptors (gut)

What receptors in the gut are stimulated by Staphylococcus enterotoxins, inducing diarrhea and vomiting?

Cognate receptor (DENV)

What cell surface receptor does the Dengue virus envelope protein bind to for normal entry into host cells?

Fc receptor (DENV)

What cell surface receptor is involved in antibody-dependent enhancement in Dengue virus infection, facilitating increased viral internalization by sub-neutralizing antibodies?

Receptor ATR

What host cell receptor does the Protective Antigen of Bacillus anthracis toxin attach to, initiating endocytosis of the exotoxins?

SNARE proteins

What protein complex (Synaptobrevin, SNAP-25, Syntaxin) is crucial for normal neurotransmitter release but is cleaved by Botulinum toxin?

E-cadherin

What receptor on host cells binds to Internalin A of Listeria monocytogenes to facilitate bacterial entry?

Glycoprotein Ib (GpIb)

What platelet surface receptor binds to von Willebrand Factor (vWF), mediating platelet adhesion to exposed subendothelial collagen?

Glycoprotein IIb-IIIa (GpIIb-IIIa)

What platelet surface receptor binds fibrinogen, connecting multiple platelets to form large aggregates?

Toll-like receptors (TLRs)

What receptors recognize microbial elements and trigger immune responses that initiate sepsis?

Prothrombin (Factor II)

What protein, involved in primary and common hemostasis, is converted to thrombin?

Fibrinogen

What soluble protein in the common coagulation pathway is converted to insoluble fibrin by thrombin?

Fibrin clot

What insoluble protein structure is the endpoint of secondary hemostasis, forming a stable plug?

Factor XII (Hageman factor)

What coagulation factor initiates the intrinsic pathway of the coagulation cascade?

Factor XI

What coagulation factor is involved in the intrinsic pathway of the coagulation cascade?

Factor IX

What coagulation factor is involved in the intrinsic pathway of the coagulation cascade?

Factor VIII

What coagulation factor is involved in the intrinsic pathway and is carried by von Willebrand Factor?

Factor VII

What coagulation factor is involved in the extrinsic pathway of the coagulation cascade?

Factor X

What coagulation factor is involved in the common pathway of the coagulation cascade?

Factor V

What coagulation factor is involved in the common pathway of the coagulation cascade?

Histamine (wound healing)

What molecule causes vasodilation and increased vascular permeability in the inflammatory phase of wound healing?

Collagen

What major ECM protein is synthesized by fibroblasts, being Type I normally and Type III during repair?

Glycosaminoglycan

What molecule, synthesized by fibroblasts, couples with proteins to form proteoglycans?

Proteoglycans (ECM)

What molecules are formed by glycosaminoglycans coupling with proteins?

Myofibroblasts

What specialized cells are crucial for wound contraction?

Polypeptides

What chemical class do growth factors and cytokines belong to?

Albumin

What protein is primarily responsible for maintaining plasma oncotic pressure, and its deficiency can lead to edema?

Interleukin 1 (IL-1)

What pyrogenic protein is elicited by peptidoglycan and activates the complement system and PMNs?

Protein A

What S. aureus adhesin binds to the Fc region of IgG, inhibiting opsonization and phagocytosis?

Clumping Factor

What S. aureus adhesin binds to fibrinogen and platelets, promoting bacterial aggregation and helping hide bacteria?

Peptidoglycan

What Gram-positive cell wall component elicits IL-1 and activates the complement system and PMNs?

Teichoic acid

What Gram-positive cell wall component serves as a biomarker for S. aureus in active endocarditis?

Capsules (bacterial)

What polysaccharide structure, found in some bacteria like S. aureus and S. pneumoniae, inhibits phagocytosis?

MSCRAMM (Microbial Surface Components Recognizing Adhesive Matrix Molecules)

What bacterial surface molecules facilitate host adherence?

Fibrin

What insoluble protein solidifies and stabilizes the primary hemostatic plug into a definitive secondary hemostatic plug?

Cytokines (tissue response)

What small chemical mediators are released by injured tissue to attract WBCs and cause vasodilation?

Chemokines

What chemical mediators specifically attract white blood cells to a site of injury?

M protein

What Streptococcus pyogenes virulence factor prevents phagocytosis, mediates bacterial attachment, and can cause rheumatic fever due to antibody cross-reactivity?

CAMP Factor

What protein promotes synergistic hemolysis of RBCs between Streptococcus and Staphylococcus?

Capsular polysaccharides (Streptococcus)

What Streptococcus components are used for serotyping and vaccine development?

E Envelope Protein Dimer (DENV)

What DENV surface protein facilitates viral entry into host cells by interfering with endosomal phospholipid bilayers?

M Membrane Protein (DENV)

What DENV structural protein is synthesized in the host's endoplasmic reticulum?

Capsid Protein (DENV)

What DENV structural protein encloses the viral RNA genome?

Non-structural Protein 1 (NS1) (DENV)

What DENV protein is solubilized by the virus and detected as an antigen for dengue diagnostic tests?