Pneumolysin

File:Pneumolysin-protein-3d-structure-RCSB.jpg

Pneumolysin is a virulence factor of the Gram-positive bacteria Streptococcus pneumoniae.{{cite journal|last1= Rossjohn |first1= J |last2= Gilbert |first2= RJ |last3= Crane |first3= D |last4= Morgan |first4= PJ |last5= Mitchell |first5= TJ |last6= Rowe |first6= AJ |last7= Andrew |first7= PW |last8= Paton |first8= JC |last9= Tweten |first9= RK |last10= Parker |first10= MW |display-authors= 4 |title= The molecular mechanism of pneumolysin, a virulence factor from Streptococcus pneumoniae |journal=Journal of Molecular Biology|date=Nov 27, 1998|volume=284|issue=2|pages=449–61|pmid=9813129|doi=10.1006/jmbi.1998.2167}}

It is a pore-forming toxin of 53 kDa composed of 471 amino acids.{{cite journal|last1= Marriott |first1= HM |last2= Mitchell |first2= TJ |last3= Dockrell |first3= DH |title= Pneumolysin: A double-edged sword during the host-pathogen interaction |journal= Current Molecular Medicine |date= September 2008 |volume= 8 |issue= 6 |pages= 497–509 |pmid= 18781957 |doi= 10.2174/156652408785747924}} It has a range of biological activity, including the ability to lyse{{cite journal |last1= Baba |first1= H |last2= Kawamura |first2= I |last3= Kohda |first3= C |last4=Nomura |first4= T |last5= Ito |first5= Y |last6= Kimoto |first6= T |last7= Watanabe |first7= I |last8= Ichiyama |first8= S |last9= Mitsuyama |first9= M |display-authors= 4 |title=Essential role of domain 4 of pneumolysin from Streptococcus pneumoniae in cytolytic activity as determined by truncated proteins |journal=Biochemical and Biophysical Research Communications|date= February 16, 2001|volume=281|issue=1|pages=37–44|pmid=11178957|doi=10.1006/bbrc.2001.4297}} and interfere with the function of cells and soluble molecules of the immune system.{{cite journal |last1= Hirst |first1= RA |last2= Kadioglu |first2= A |last3= O'callaghan |first3= C |last4=Andrew |first4= PW |title=The role of pneumolysin in pneumococcal pneumonia and meningitis.|journal=Clinical and Experimental Immunology |date= November 2004 |volume= 138 |issue= 2 |pages= 195–201 |pmid= 15498026 |doi= 10.1111/j.1365-2249.2004.02611.x |pmc= 1809205}}

Released pneumolysin will aid the bacteria during colonization by facilitating adherence to the host,{{cite journal |last1= Rubins |first1= JB |last2= Paddock |first2= AH |last3= Charboneau |first3= D |last4= Berry |first4= AM |last5= Paton |first5= JC |last6= Janoff |first6= EN |display-authors= 4 |title= Pneumolysin in pneumococcal adherence and colonization |journal= Microbial Pathogenesis |date= December 1998 |volume= 25 |issue= 6 |pages= 337–42 |pmid= 9895272 |doi= 10.1006/mpat.1998.0239}} during invasion by damaging host cells{{cite journal |last1= Rubins |first1= JB |last2= Janoff |first2= EN |title=Pneumolysin: A multifunctional pneumococcal virulence factor |journal= The Journal of Laboratory and Clinical Medicine |date= January 1998 |volume= 131 |issue= 1 |pages= 21–7 |pmid= 9452123 |doi= 10.1016/s0022-2143(98)90073-7}} and during infection by interfering with the host immune response.{{cite journal |last1= Cockeran |first1= R |last2= Anderson |first2= R |last3= Feldman |first3= C |title= The role of pneumolysin in the pathogenesis of Streptococcus pneumoniae infection |journal=Current Opinion in Infectious Diseases |date= June 2002 |volume= 15 |issue= 3 |pages= 235–9 |pmid= 12015456 |doi= 10.1097/00001432-200206000-00004}}

The presence of pneumolysin in sputum,{{cite journal |last1= Wheeler |first1= J |last2= Freeman |first2= R |last3= Steward |first3= M |last4= Henderson |first4= K |last5= Lee |first5= MJ |last6= Piggott |first6= NH |last7= Eltringham |first7= GJ |last8= Galloway |first8= A |display-authors= 4 |title= Detection of pneumolysin in sputum |journal=Journal of Medical Microbiology |date= September 1999 |volume= 48 |issue= 9 |pages= 863–6 |pmid= 10482298 |doi= 10.1099/00222615-48-9-863}} urine,{{cite journal |last1= Rajalakshmi |first1= B |last2= Kanungo |first2= R |last3= Srinivasan |first3= S |last4= Badrinath |first4= S |title= Pneumolysin in urine: A rapid antigen detection method to diagnose pneumococcal pneumonia in children |journal= Indian Journal of Medical Microbiology |date= Oct–Dec 2002 |volume= 20 |issue= 4 |pages= 183–6 |pmid= 17657067}} CSF{{cite journal |last1= Matos Jde |first1= A |last2= Madureira |first2= DJ |last3= Rebelo |first3= MC |last4= Hofer |first4= CB |last5= Barroso |first5= DE |display-authors= 4 |title= Diagnosis of Streptococcus pneumoniae meningitis by polymerase chain reaction amplification of the gene for pneumolysin |journal= Memórias do Instituto Oswaldo Cruz |date= August 2006 |volume= 101 |issue= 5 |pages= 559–63 |pmid= 17072463 |doi= 10.1590/s0074-02762006000500014|doi-access= free }} and blood{{cite journal |last1= Lahti |first1= E |last2= Mertsola |first2= J |last3= Kontiokari |first3= T |last4= Eerola |first4= E |last5= Ruuskanen |first5= O |last6= Jalava |first6= J |display-authors= 4 |title= Pneumolysin polymerase chain reaction for diagnosis of pneumococcal pneumonia and empyema in children |journal= European Journal of Clinical Microbiology & Infectious Diseases |date= December 2006 |volume= 25 |issue= 12 |pages= 783–9 |pmid= 17089094 |doi= 10.1007/s10096-006-0225-9}} can be indicative of an S. pneumoniae infection.