Signal Peptides

Origin of signal peptide	Amino acid sequence	% relative activity
Gaussia luciferase	MGVKVLFALICIAVAEA	100
Human albumin	MKWVTFISLLFLFSSAYS	5
Human chymotrypsinogen	MAFLWLLSCWALLGTTFG	59
Human interleukin-2	MQLLSCIALILALV	37
Human trypsinogen-2	MNLLLILTFVAAAVA	71

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4338144/

heavy
MELGLSWIFLLAILKGVQC ATGGAGTTGGGACTGAGCTGGATTTTCCTTTTGGCTATTTTAAAAGGTGTCCAGTGT
MELGLRWVFLVAILEGVQC ATGGAACTGGGGCTCCGCTGGGTTTTCCTTGTTGCTATTTTAGAAGGTGTCCAGTGT
MKHLWFFLLLVAAPRWVLS ATGAAACACCTGTGGTTCTTCCTCCTGCTGGTGGCAGCTCCCAGATGGGTCCTGTCC
MDWTWRILFLVAAATGAHS ATGGACTGGACCTGGAGGATCCTCTTCTTGGTGGCAGCAGCAACAGGTGCCCACTCG
MDWTWRFLFVVAAATGVQS ATGGACTGGACCTGGAGGTTCCTCTTTGTGGTGGCAGCAGCTACAGGTGTCCAGTCC
MEFGLSWLFLVAILKGVQC ATGGAGTTTGGGCTGAGCTGGCTTTTTCTTGTGGCGATTCTAAAAGGTGTCCAGTGT
MEFGLSWVFLVALFRGVQC ATGGAGTTTGGGCTGAGCTGGGTTTTCCTCGTTGCTCTTTTTAGAGGTGTCCAGTGT
MDLLHKNMKHLWFFLLLVAAPRWVLS ATGGACCTCCTGCACAAGAACATGAAACACCTGTGGTTCTTCCTCCTCCTGGTGGCAGCTCCCAGATGGGTGCTGTCC
light chain Amino acid sequence DNA sequence
L1 MDMRVPAQLLGLLLLWLSGARC ATGGACATGAGGGTCCCTGCTCAGCTCCTGGGGCTCCTGCTGCTCTGGCTCTCAGGTGCCAGATGT
L2 MKYLLPTAAAGLLLLAAQPAMA ATGAAATACCTATTGCCTACGGCAGCCGCTGGATTGTTATTACTCGCGGCCCAGCCGGCCATGGCC

In general, residues that comprise the N-terminal region of the mature protein are either electroneutral or electronegative [4], [5], [6] (Fig. 1). Analysis of the start of mature proteins reveal a high prevalence of acidic residues, particularly in bacterial species [7]. Previous studies have shown that the addition of the signal peptide to the N-terminus of a cytoplasmic proteins is not sufficient to allow export to the periplasm in gram-negative bacteria [8], [9], [10]. Experimental evidence has shown that long hydrophobic stretches after the signal peptide cleavage site prevent export to the periplasm of pIII protein [11]. Hence, these studies indicate that N-terminus of the mature protein, adjacent to the signal peptide may contain amino acids that are permissive for, or prevent, efficient recognition and/or cleavage by signal peptidase 1.

Amino acidP1′P2′Expected 

Ala 1712140.86 

Asp3675 21.65 

Glu3170 24.03

Amino acidP1′P2′P3′P4′P5′Expected

Ala70a1212131313.715

Asp1231a41277.267

Glu1633a61098.067

i.e., P1' should be Ala, A, P2' should be Asp, D, Glu E

Based on this paper, 

https://amb-express.springeropen.com/articles/10.1186/s13568-017-0394-1

NSP4

MKKI TAAAGLLLLA AQPAMA

is much better than

E coli PelBss

MKYLLP TAAAGLLLLA AQPAMA, it is also the secretion signal for human light chain kappa https://www.ncbi.nlm.nih.gov/protein/BAC01725