If a normal prion protein comes into contact with a

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Unformatted text preview: KES A SINGLE AMINO ACID SHIFT MORE LIKELY. IF A NORMAL PRION PROTEIN COMES INTO CONTACT WITH A SCRAPIE PROTEIN, THEN A CONFORMATIONAL SHIFT WILL HAPPEN AUTOMATICALLY EVEN IN A NORMAL PROTEIN. WHAT HAPPENS IS THERE IS A INTRODUCTION OF A NORMAL PRION PROTEIN IN A GROUP OF NORMAL PROTEINS AND A CONFORMATIONAL SHIFT OCCURS (LIKE AN ICE CRYSTAL)—ONE PRION AFFECTS NEIGHBORS AND CONTINUES TO FORM A CLUSTER OF ABNORMAL PROTEINS THAT HAVE UNDERGONE CONFORMATIONAL SHIFT. “SLOW VIRUSES” PRION PROTEIN: REPRESENTED AS BETA-PLEATED SHEET CONFORMATION. NORMAL PROTEIN IN OUT CELLS FUNCTION IS PROBABLY CHAPERONIN TO PROTECT FROM HEAT OR STRESS DAMAGE SAME AMINO ACID SEQ, DIFF CONFORMATIONAL SHAPE WHEN PRION PROTEIN COMES INTO CONTACT WITH NORMAL PROTEIN, PRION FACILITATES A CHANGE IN AMINO ACID SEQUENCE TO FORM BETA-PLEATED SHEET. PRIONS Prion protein Amyloid plaques (CJD) IN BRAIN TISSUE, AMYLOID PLAQUES FORM. AMYLOID PLAQUES CRYSTALLIZE AND RECRUIT, CELLS MAKE MORE PROTEIN DUE TO LOSS OF PROTEIN AND AMYLOID PLAQUES CONTINUE TO GROW. AMYLOID PLAQUES CAN PROGRESS INTO SPONGIFORM ENCEPHALOPATHY (SPONGE APPEARANCE) LEADS TO SPONGIFORM ENCEP. cow brain (normal) cow brain (BSE) CJD CAN LEAD TO LOSS OF BRAIN FUNCTION HOW THIS OCCURS? SPONTANEOUS! THEN GIVEN TO REST OF POPULATION INHEIRITED DUE TO SINGLE GENE PREDISPOSITION SOMATIC MUTATION THAT LEADS TO CONVERSION 12/4 27:38 SEEMS TO BE ALIVE FOR ALL PRACTICAL PURPOSES IN MICROBIOLOGY, VIRUSES AND PRIONS ARE CONSIDERED ALIVE DUE TO REPLICATION E. coli RICKESTTSIA CHLAMYDIA Nucleic acid: DNA& MYCOPLASMA VIRUS PRION DNA& RNA DNA& RNA DNA& RNA Ribosomes: 70s 70s 70s Cell wall: PG (-?) RNA PG yes DNAor RNA none 70s none none none none none (?) no no yes no no Binary fission: yes yes Macro-molecular synthesis yes some yes ATP-generating system yes yes no yes no no Sensitive to penicillin: yes yes yes no no no Sensitive to yes yes yes yes no no...
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This document was uploaded on 02/25/2014 for the course MICROBIOLO 101 at San Jose State University .

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