I'd do it this way: (This requires 5.8.x) 

$str = 'MKTVEQTSPTMTSEKARWIY ... ELLTDVYVSYDHEGRNG';
print join ' ', unpack '(a10)*', $_ for unpack '(a50)*', $str;;

MKTVEQTSPT MTSEKARWIY QKMVEIRMFE DRVHDIFSKG EIPGFVHLYA
GEEAIAVGLC AHLDHNDYIT STHRGHGHCI AKGCELDGMM AEIYGKSTGL
CKGKGGSMHI ADLDRGMLGA NGIVGGGFTL AAGAALTAKF KQTGGVAVCF
FGDGANNQGT FHEGINLAAI WDLPVVFVAE NNGYGEATPF HYASACEQIT
DRAKGYNIPG VKVDGKDVVA VYEVAREAVE RARRGEGPTL IECITYRNYG
HFEGDAQTYK TGREKEEHTE ERDAITLFEK YALSNNLLTE EAIQTVRHEV
EQSVDRAVDF ANASDYPQPE ELLTDVYVSY DHEGRNG

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Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal?
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In the absence of evidence, opinion is indistinguishable from prejudice.

In reply to Re: spliting a lengthy text by BrowserUk
in thread splitting and coloring by sanku

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