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Ok leggiamolo questo articolo.
SARS-CoV-2 seems to have an RBD that binds with high affinity to ACE2 from humans, ferrets, cats and other species with high receptor homology7.
First, the sequence of 2019-nCoV RBD, including its receptor-binding motif (RBM) that directly contacts ACE2, is similar to that of SARS-CoV, strongly suggesting that 2019-nCoV uses ACE2 as its receptor. Second, several critical residues in 2019-nCoV RBM (particularly Gln493) provide favorable interactions with human ACE2, consistent with 2019-nCoV’s capacity for human cell infection. Third, several other critical residues in 2019-nCoV RBM (particularly Asn501) are compatible with, but not ideal for, binding human ACE2, suggesting that 2019-nCoV has acquired some capacity for human-to-human transmission. Last, while phylogenetic analysis indicates a bat origin of 2019-nCoV, 2019-nCoV also potentially recognizes ACE2 from a diversity of animal species (except mice and rats),
Ok, devono decidersi, o ha affinità o non ce l'ha.
While the analyses above suggest that SARS-CoV-2 may bind human ACE2 with high affinity, computational analyses predict that the interaction is not ideal and that the RBD sequence is different from those shown in SARS-CoV to be optimal for receptor binding7,11. Thus, the high-affinity binding of the SARS-CoV-2 spike protein to human ACE2 is most likely the result of natural selection on a human or human-like ACE2 that permits another optimal binding solution to arise. This is strong evidence that SARS-CoV-2 is not the product of purposeful manipulation.
Perchè ?
No sul serio, perchè ?
Nessuna motivazione, hanno deciso che è naturale, così.
It is improbable that SARS-CoV-2 emerged through laboratory manipulation of a related SARS-CoV-like coronavirus. As noted above, the RBD of SARS-CoV-2 is optimized for binding to human ACE2 with an efficient solution different from those previously predicted7,11. Furthermore, if genetic manipulation had been performed, one of the several reverse-genetic systems available for betacoronaviruses would probably have been used
Perchè ? Perchè devono per forza usare i modelli che vuoi tu ? La logica è ancora "non hanno fatto come farei io, quindi è naturale".
However, the genetic data irrefutably show that SARS-CoV-2 is not derived from any previously used virus backbone
E ? Non hanno usato i virus che vuoi tu ? E ?
As many early cases of COVID-19 were linked to the Huanan market in Wuhan1,2, it is possible that an animal source was present at this location. Given the similarity of SARS-CoV-2 to bat SARS-CoV-like coronaviruses2, it is likely that bats serve as reservoir hosts for its progenitor. Although RaTG13, sampled from a Rhinolophus affinis bat1, is ~96% identical overall to SARS-CoV-2, its spike diverges in the RBD, which suggests that it may not bind efficiently to human ACE2
Ok, quindi da dove è arrivata la mutazione ?
Malayan pangolins (Manis javanica) illegally imported into Guangdong province contain coronaviruses similar to SARS-CoV-221. Although the RaTG13 bat virus remains the closest to SARS-CoV-2 across the genome1, some pangolin coronaviruses exhibit strong similarity to SARS-CoV-2 in the RBD, including all six key RBD residues21 (Fig. 1). This clearly shows that the SARS-CoV-2 spike protein optimized for binding to human-like ACE2 is the result of natural selection.
Ok allora sono stati i pipistrelli o i pangolini ?
Neither the bat betacoronaviruses nor the pangolin betacoronaviruses sampled thus far have polybasic cleavage sites.
AH, e questo come lo spiegate allora ?
Although no animal coronavirus has been identified that is sufficiently similar to have served as the direct progenitor of SARS-CoV-2, the diversity of coronaviruses in bats and other species is massively undersampled.
ok la loro logica, ancora è, "non sappiamo abbastanza dei pipistrelli e dei pangolini".
Che la cosa sia chiara, gente, io gli articoli che postate li leggo, a differenza vostra.
Al momento stanno navigando a vista, dicendo che bisogna fare altre ricerche, non hanno trovato alcun coronavirus di base animale che sia progenitore di questo qui. Nulla.
Nel mentre i cinesi sperimentano dal 2015 con pipistrelli topi e dio solo sa quali altri animali con centinaia di ricercatori che ci vivono assieme.
Ma diamo all'articolo il beneficio del dubbio, vi va ? Proseguiamo.
Mutations, insertions and deletions can occur near the S1–S2 junction of coronaviruses22, which shows that the polybasic cleavage site can arise by a natural evolutionary process.
Ok, quindi dato che i coronavirus mutano, così come tutti i virus, questo può essere naturale.
Che sia ancora più chiaro, stanno dicendo, "dato che i virus mutano, questo è mutato".
Studies of banked human samples could provide information on whether such cryptic spread has occurred. Retrospective serological studies could also be informative, and a few such studies have been conducted showing low-level exposures to SARS-CoV-like coronaviruses in certain areas of China26. Critically, however, these studies could not have distinguished whether exposures were due to prior infections with SARS-CoV, SARS-CoV-2 or other SARS-CoV-like coronaviruses. Further serological studies should be conducted to determine the extent of prior human exposure to SARS-CoV-2.
E questo è per quanto riguarda la POSSIBILE via "naturale".
3. Selection during passage
Basic research involving passage of bat SARS-CoV-like coronaviruses in cell culture and/or animal models has been ongoing for many years in biosafety level 2 laboratories across the world27, and there are documented instances of laboratory escapes of SARS-CoV28. We must therefore examine the possibility of an inadvertent laboratory release of SARS-CoV-2.
E
The acquisition of both the polybasic cleavage site and predicted O-linked glycans also argues against culture-based scenarios. New polybasic cleavage sites have been observed only after prolonged passage of low-pathogenicity avian influenza virus in vitro or in vivo17.
E non è questo che esattamente succede in un laboratorio di ricerca ? Ancora, mi sembra di essere preso in giro.
Furthermore, a hypothetical generation of SARS-CoV-2 by cell culture or animal passage would have required prior isolation of a progenitor virus with very high genetic similarity, which has not been described.
Non "che non è successo", ma "di cui non sappiamo nulla".
Subsequent generation of a polybasic cleavage site would have then required repeated passage in cell culture or animals with ACE2 receptors similar to those of humans, [B]but such work has also not previously been described.
Cosa diavolo vuol dire "has not been described ?"
Mi hai appena detto che i gatti hanno i nostri stessi recettori ! E poi hai detto che non ce li hanno !Che i furetti hanno i nostri stessi recettori !
COSA esattamente avrebbe impedito di fare esperimenti su animali che hanno i nostri stessi recettori ? Cosa ?
Has not been described ? We need more researches ?
Ok, continuate pure a ricercare. Ma che sia chiaro, non hanno la più pallida idea al momento, da dove sia arrivato e come si sia evoluto, E LO DICONO APERTAMENTE NEGLI ARTICOLI CHE MI LINKATE DICENDOMI "GUARDA COGLIONE, HANNO DIMOSTRATO TUTTO"
Almeno LEGGETELI gli articoli che mi postate.
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